Blood Disorders

Coding Dimension ID: 
278
Coding Dimension path name: 
Blood Disorders
Funding Type: 
Strategic Partnership II
Grant Number: 
SP2-06902
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$6 374 150
Disease Focus: 
Blood Disorders
Pediatrics
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
β-thalassemia is a genetic disease caused by diverse mutations of the β-globin gene that lead to profoundly reduced red blood cell (RBC) development. The unmet medical need in transfusion-dependent β-thalassemia is significant, with life expectancy of only ~30-50 years despite standard of care treatment of chronic blood transfusions and iron chelation therapy. Cardiomyopathy due to iron overload is the major cause of mortality, but iron-overload induced multiorgan dysfunction, blood-borne infections, and other disease complications impose a significant physical, psychosocial and economic impact on patients and families. An allogeneic bone marrow transplant (BMT) is curative. However, this therapy is limited due to the scarcity of HLA-matched related donors (<20%) combined with the significant risk of graft-versus-host disease (GvHD) after successful transplantation of allogeneic cells. During infancy, gamma-globin-containing fetal hemoglobin protects β-thalassemia patients from developing disease symptoms until gamma globin is replaced by adult-type β-globin chains. The proposed therapeutic intervention combines the benefits of re-activating the gamma globin gene with the curative potential of BMT, but without the toxicities associated with acute and chronic immunosuppression and GvHD. We hypothesize that harvesting hematopoietic stem and progenitor cells (HSPCs) from a patient with β-thalassemia, using genome editing to permanently re-activate the gamma globin gene, and returning these edited HSPCs to the patient could provide transfusion independence or greatly reduce the need for chronic blood transfusions, thus decreasing the morbidity and mortality associated with iron overload. The use of a patient’s own cells avoids the need for acute and chronic immunosuppression, as there would be no risk of GvHD. Moreover, due to the self-renewing capacity of HSPCs, we anticipate a lifelong correction of this severe monogenic disease.
Statement of Benefit to California: 
Our proposed treatment for transfusion dependent β-thalassemia will benefit patients in the state by offering them a significant improvement over current standard of care. β-thalassemia is a genetic disease caused by diverse mutations of the β-globin gene that lead to profoundly reduced red blood cell (RBC) development and survival resulting in the need for chronic lifelong blood transfusions, iron chelation therapy, and important pathological sequelae (e.g., endocrinopathies, cardiomyopathies, multiorgan dysfunction, bloodborne infections, and psychosocial/economic impact). Incidence is estimated at 1 in 100,000 in the US, but is more common in the state of California (incidence estimated at 1 in 55,000 births) due to immigration patterns within the State. While there are estimated to be about 1,000-2,000 β-thalassemia patients in the US, one of our proposed clinical trial sites has the largest thalassemia program in the Western United States, with a population approaching 300 patients. Thus, the state of California stands to benefit disproportionately compared to other states from our proposed treatment for transfusion dependent β-thalassemia. An allogeneic bone marrow transplant (BMT) is curative for β-thalassemia, but limited by the scarcity of HLA-matched related donors (<20%) combined with the significant risk of graft-versus-host disease (GvHD) after successful transplantation of allogeneic cells. Our approach is to genetically engineer the patient’s own stem cells and thus (i) solve the logistical challenge of finding an appropriate donor, as the patient now becomes his/her own donor; and (ii) make use of autologous cells abrogating the risk of GvHD and need for acute and chronic immunosuppression. Our approach offers a compelling pharmacoeconomic benefit to the State of California and its citizens. A lifetime of chronic blood transfusions and iron chelation therapy leads to a significant cost burden; despite this, the prognosis for a transfusion dependent β-thalassemia patient is still dire, with life expectancy of only ~30-50 years. Our proposed one-time treatment aims to reduce or eliminate the need for costly chronic blood transfusions and iron chelation therapy, while potentially improving the clinical benefit to patients, including the morbidity and mortality associated with transfusion-induced iron overload.
Progress Report: 
  • Summary of progress
  • Our CIRM-funded effort aims to develop a treatment for beta-thalassemia. Beta-thalassemia is an inherited genetic disorder that is caused by mutations (changes in the DNA) in a gene called beta-globin. This gene produces a protein that forms hemoglobin in red blood cells that carry oxygen to through the body. In an individual with beta-thalassemia, beta-globin is not produced (or is made in dramatically reduced quantities), and so the person does not make enough healthy red blood cells. The treatment, which is essential for life in these patients, is repeated blood transfusions (typically once a month or more frequently). The transfusion of blood this frequently results in a dangerous condition called “iron overload,” which must be treated with costly drugs. In general, the quality of life of many people with beta-thalassemia is poor.
  • At present, there is only one cure, and that is to carry out a bone marrow transplant. This involves taking special cells from a healthy person called “hematopoietic stem cells” that give rise to blood cells for the whole of a person's life, and giving them to the patient so that they that they are now able to make healthy red blood cells for their lifetime. However, the cell donor must be an immunologic match to the patient and for many people with beta-thalassemia, such donors are not available.
  • Our approach to treating beta-thalassemia aims to genetically engineer a person’s hematopoietic stem cells (change the DNA inside the cell) to allow them to make healthy red blood cells using a technology that we have developed called "zinc finger nucleases,” or ZFNs. We plan to obtain stem cells from a beta-thalassemia patient, genetically engineer them by transiently exposing them to ZFNs, and then transplant them back into the same individual, making the patient their own donor. The genetic engineering is designed to replicate a situation observed in certain people with beta-thalassemia who have milder symptoms than others. Such patients have a much higher than average level of a “backup” form of beta-globin, called fetal globin, in their blood.
  • All people make fetal globin while in utero and after birth, but in infancy the levels of fetal globin decrease and the child begins to make adult beta-globin. It is at this stage that the symptoms of beta-thalassemia become evident. However, if person with beta-thalassemia has high level of fetal globin, they will be spared the severe effects of the disease.
  • We know that certain individuals who have an elevated level of fetal globin do so because they have a less active form of a gene called BCL11A that normally shuts down the production of fetal globin during infancy. Making use of this observation, our approach is to knock out BCL11A in a patient’s own stem cells, transplant them back into the patient to allow the production of fetal hemoglobin and, as a consequence, increase production of healthy red blood cells.
  • In order to test drugs in humans investigators must consult with the US Federal Drug Administration (FDA) and ultimately submit data about the investigational drug to various regulatory bodies including the FDA as part of Investigational New Drug (IND) application. This past year, we held a meeting with the Center for Biologics Evaluation and Research of the FDA known as a “pre-IND” and received useful guidance on issues that we should address in preparing the IND filing. We also presented our program to the Recombinant DNA Advisory Committee of the NIH (RAC); our proposed preclinical safety assessment program and plan for the phase I clinical trial received unanimous approval from the RAC.
  • Our work this year focused on two major deliverables that are necessary to achieve the goal of beginning a clinical trial of our approach. The first one relates to our ability to purify and efficiently genetically engineer a sufficient quantity of stem cells from a patient with beta-thalassemia. Working with healthy volunteers, and in a setting that is identical to the one we plan to use during our clinical trial, we have been able to consistently obtain sufficient quantities of hematopoietic stem cells to treat an individual with beta-thalassemia, and attain high levels of targeted genetic engineering in those cells.
  • As part of a preclinical safety assessment program, we have initiated and completed a series of studies to determine whether the genetic engineering we perform has any unforeseen untoward consequences in the cell. When we have completed this effort, we aim to file the IND application with the FDA before the end of the year and, pending FDA acceptance, initiate the phase 1 clinical trial in 2015.
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06809
Investigator: 
ICOC Funds Committed: 
$2 322 440
Disease Focus: 
Blood Disorders
Liver Disease
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Hemophilia B is a bleeding disorder caused by the lack of FIX in the plasma and affects 1/30,000 males. Patients suffer from recurrent bleeds in soft tissues leading to physical disability in addition to life threatening bleeds. Current treatment (based on FIX infusion) is transient and plagued by increased risk for blood-borne infections (HCV, HIV), high costs and limited availability. This has fueled a search for gene/cell therapy based alternatives. Being the natural site of FIX synthesis, the liver is expected to provide immune-tolerance and easy circulatory access. Liver transplantation is a successful, long-term therapeutic option but is limited by scarcity of donor livers and chronic immunosuppression; making iPSC-based cell therapy an attractive prospect. As part of this project, we plan to generate iPSCs from hemophilic patients that will then be genetically corrected by inserting DNA capable of making FIX. After validation for correction, we will then differentiate these iPSCs into liver cells that can be transplanted into our mouse model of hemophilia that is capable of accepting human hepatocytes and allowing their proliferation. These mice exhibit disease symptoms similar to human patients and we propose that by injecting our corrected liver cells they will exhibit normal clotting as measured by various biochemical and physiological assays. If successful, this will provide a long-term cure for hemophilia and other liver diseases.
Statement of Benefit to California: 
Generation of iPSCs from adult cells unlocked the potential of tissue engineering, replacement and cell transplant therapies to cure a host of debilitating diseases without the ethical concerns of working with embryos or the practical problems of immune-rejection. We aim to develop a POC for a novel cell- and gene-therapy based approach towards the treatment of hemophilia B. In addition to the obvious and direct benefit to the affected patients and families by providing a potential long-term cure; the successful development of our proposal will serve as a POC for moving other iPSC-based therapies to the clinic. Our proposal also has the potential to treat a host of other hepatic diseases like alpha-1-antitrypsin deficiency, Wilson’s disease, hereditary hypercholesterolemia, etc. These diseases have devastating effects on the patients in addition to the huge financial drain on the State in terms of the healthcare costs. There is a pressing need to find effective solutions to such chronic health problems in the current socio-economic climate. The work proposed here seeks to redress this by developing cures for diseases that, if left untreated, require substantial, prolonged medical expenditures and cause increased suffering to patients. Being global leaders in these technologies, we are ideally suited to this task, which will establish the state of California at the forefront of medical breakthroughs and strengthen its biomedical/biotechnology industries.
Progress Report: 
  • Hemophilia B is a bleeding disorder caused by the lack of FIX in the plasma and affects 1 in 30,000 males. Patients suffer from recurrent bleeds in soft tissues leading to physical disability in addition to life threatening bleeds. Current treatment (based on FIX infusion) is transient and plagued by increased risk for blood-borne infections (HCV, HIV), high costs and limited availability. This has fueled a search for gene/cell therapy based alternatives. Gene therapy with viruses is beset with problems of safety and increased immunogenicity. Being the natural site of FIX synthesis, the liver is expected to provide immune-tolerance and easy circulatory access. Liver transplantation is a successful, long-term therapeutic option but is limited by scarcity of donor livers and chronic immunosuppression, making iPSC-based cell therapy an attractive prospect. As part of this project, we will generate iPSCs from hemophilic patients that will be genetically corrected by inserting FIX coding DNA. After correction, we will differentiate these iPSCs into liver cells which will then be transplanted into our mouse model of hemophilia that can accept human hepatocytes and allow their proliferation. These mice exhibit disease symptoms similar to human patients and we propose that by injecting our corrected liver cells they will exhibit normal clotting as measured by various biochemical and physiological assays. If successful, this will provide a long-term cure for hemophilia and will serve as a proof-of-concept for the treatment of other liver diseases.
  • With this long term aim, during the first year of the project, we have procured two hemophilic patient samples and two control samples from our collaborators. We have successfully generated iPSCs with no long-term genomic changes. We are currently working towards identifying the mutations in the patients that were responsible for the disease. Our efforts are presently directed towards correcting the mutations in the patient derived iPSCs so that they can now produce a functional FIX protein.
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06823
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$1 815 308
Disease Focus: 
Blood Disorders
Pediatrics
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Disorders affecting the blood, including Sickle Cell Disease (SCD), are the most common genetic disorders in the world. SCD causes significant suffering and early death, despite major improvements in medical management and advances in understanding the complex disease-related biology. A bone marrow transplant (BMT) can greatly benefit patients with SCD, by providing a life-long source of normal red blood cells. However, BMT is limited by the availability of suitable donors and immune complications, especially for the more than 80% of patients who lack a matched sibling donor. An alternative treatment approach for SCD is to isolate some of the patient’s own bone marrow and then use gene therapy methods to correct the sickle gene defect in the blood stem cells before transplanting them back into the patient. The gene-corrected stem cells could make normal blood cells for the life of the patient, essentially eliminating the SCD. Such an approach would avoid the complications typically associated with transplants from non-matched donors. We will define the optimal techniques to correct the sickle gene mutation in the bone marrow stem cells to develop as a therapy for patients with SCD.
Statement of Benefit to California: 
Development of methods for regenerative medicine using stem cells will have widespread applications to improve the health and to provide novel, effective therapies for millions of Californians and tens of millions of people worldwide. Many severe medical conditions can be cured or improved by transplantation of blood-forming hematopoietic stem cells (HSC), including genetic diseases of blood cells, such as sickle cell disease and inborn errors of metabolism, cancer and leukemia, and HIV/AIDS. Precise genetic engineering of stem cells to repair inherited mutation may be the best way to correct genetic defects affecting the mature cells they produce. This project will advance methods to precisely repair the genetic defect that underlies sickle cell disease in hematopoietic stem cells, which can then be transplanted to ameliorate the disease. These advances will have direct and immediate applications to enhance current medical therapies of sickle cell disease and will more broadly help to advance the capacities for regenerative medicine. All scientific findings and biomedical materials produced from our studies will be publicly available to non-profit and academic organizations in California, and any intellectual property developed by this Project will be developed under the guidelines of CIRM to benefit the people of the State of California.
Progress Report: 
  • Sickle-cell disease (SCD) is characterized by a single point mutation in the seventh codon of the beta-globin gene. Site-specific correction of the sickle mutation in adult bone marrow hematopoietic stem cells (HSCs) would allow for permanent production of normal red blood cells. Site-specific correction can be achieved using proteins called zinc-finger nucleases (ZFNs) which recognize and bind the region of the genome surrounding the sickle mutation. The ZFNs are able to create a break in the DNA which the cells repair using existing repair machinery. If, at the time of repair, a homologous donor template containing the corrective base is present, the cells' repair machinery can use this template and the resulting cell genome will contain the wild-type base instead of the sickle mutation. By doing this in hematopoietic setm cells, the cell is permanently corrected and each red blood cell (RBC) derived from this corrected stem cell will produce normal, non-sickle RBCs. In this report, we show efficient targeted cleavage by the ZFNs at the beta-globin locus with minimal off-target modification. In addition, we compare two different homologous donor templates (an integrase-defective lentiviral vector [IDLV] and a single-stranded DNA oligonucleotide [oligo]) to determine the optimal donor template. In both wild-type as well as sickle cell disease patient CD34+ HSCs, we are able to deliver the ZFN and donor templates and specifically correct the genome at rates of up to 30%. When these cells are differentiated into RBCs in vitro, we demonstrate that they are not altered in their differentiation capacity and are able to produce wild-type hemoglobin at high levels (35% of all hemoglobins) by HPLC. These results provide a strong basis for moving forward with this work as we begin our efforts to increase the number of treated cells to achieve clinical levels of corrected cells as well as characterize the ability of these cells to engraft a murine model in vivo. The progress made in this year is an exciting step towards a clinical therapy and potential treatment for sickle cell disease.
Funding Type: 
Strategic Partnership I
Grant Number: 
SP1-06477
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$9 363 335
Disease Focus: 
Blood Disorders
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Closed
Public Abstract: 
[REDACTED] plans to carry out a Phase 1/2 study to evaluate the safety and efficacy of [REDACTED] for the treatment of β-Thalassemia Major(BTM). [REDACTED] consists of autologous patient hematopoietic stem cells(HSC) that have been genetically modified ex vivo with a lentiviral vector that encodes a therapeutic form of the β-globin gene. [REDACTED] is administered through autologous hematopoietic cell transplant(HCT), with the goal of restoring normal levels of hemoglobin and red blood cell(RBC) production in BTM patients who are dependent on RBC transfusions for survival. Because they cannot produce functional hemoglobin, BTM patients require lifelong RBC transfusions that cause widespread organ damage from iron overload. While hemosiderosis can be mitigated with chelation therapy, poor compliance, efficacy and tolerability remain key challenges, and a majority BTM patients die in their 3rd-5th decade. The only cure for BTM is allogeneic HCT, which carries a significant risk of mortality and morbidity from immune-incompatibility between the donor and recipient, and is hampered by the limited availability of HLA matched sibling donors. By stably inserting functional copies of β-globin into the genome of a patient’s own HSC, treatment with [REDACTED] promises to be a one-time transformative therapy for BTM. The β-globin gene in the [REDACTED] vector carries a single codon mutation [REDACTED] that allows for quantitative monitoring of therapeutic globin production but that does not alter oxygen carrying capacity. Treatment with an earlier version of the vector has been shown to correct β-thalassemia in mice [REDACTED]. In a clinical trial [REDACTED], 3 BTM patients were treated–one of whom became transfusion independent 1 year after treatment and remains so 4 years later. Given the prevalence of patients with a common BTM genotype in California, [REDACTED] plans to open at least 2, and up to 4, clinical sites in California. Development activities are on track to initiate the trial in 1H 2013, and to complete the trial with 2 years of follow-up within the award window. [REDACTED] has completed a pre-IND meeting with the FDA and successfully manufactured a GMP lot of [REDACTED] vector that is available for clinical use. The Company expects to complete all IND enabling activities by Q4 2012. In the last year, the company has made scientific advances that have allowed for a significant improvement in the efficiency of HSC genetic modification that will be help ensure clinical efficacy in BTM. Moreover, through collaborations with contract manufacturers, [REDACTED] is now producing large scale GMP lots of vector, and is on track to qualify a GMP cell processing facility with commercial capabilities prior to study initiation. [REDACTED].
Statement of Benefit to California: 
The company expects to spend a major component of its financial resources conducting business within the state of California during the period of this CIRM award. Specifically: 1) we will have at least two clinical sites in California, and more likely up to 4 sites, 2) our viral vector manufacturing will occur in California, 3) our cell processing will occur in California, 4) we will hire several consultants and full-time employees within California to support the program. Overall, several million dollars will be spent employing the services of people, academic institutions, and other companies within the state of California. Moreover, the disease we aim to treat occurs at a substantially greater rate of in California than other parts of the United States. As such, it is a significant public health concern, for which our therapy could provide a dramatically improved outcome and significant reduction in the lifetime cost of treatment, along with increased productivity. Due to the prevalence of the disease in California, if brought to the market, the pharmacoeconomic and social benefit of our therapy will accrue disproportionately to the state of California.
Funding Type: 
New Faculty Physician Scientist
Grant Number: 
RN3-06479
Investigator: 
ICOC Funds Committed: 
$3 084 000
Disease Focus: 
Blood Disorders
Blood Cancer
Cancer
Stem Cell Use: 
Directly Reprogrammed Cell
Cell Line Generation: 
Directly Reprogrammed Cell
oldStatus: 
Active
Public Abstract: 
The current roadblocks to hematopoietic stem cell (HSC) therapies include the rarity of matched donors for bone marrow transplant, engraftment failures, common shortages of donated blood, and the inability to expand HSCs ex vivo in large numbers. These major obstacles would cease to exist if an extensive, bankable, inexhaustible, and patient-matched supply of blood were available. The recent validation of hemogenic endothelium (blood vessel cells lining the vessel wall give rise to blood stem cells) has introduced new possibilities in hematopoietic stem cell therapy. As the phenomenon of hemogenic endothelium only occurs during embryonic development, we aim to understand the requirements for the process and to re-engineer mature human endothelium (blood vessels) into once again producing blood stem cells (HSCs). The approach of re-engineering tissue specific de-differentiation will accelerate the pace of discovery and translation to human disease. Engineering endothelium into large-scale hematopoietic factories can provide substantial numbers of pure hematopoietic stem cells for clinical use. Higher numbers of cells, and the ability to grow cells from matched donors (or the patients themselves) will increase engraftment and decrease rejection of bone marrow transplantation. In addition, the ability to program mature lineage restricted cells into more primitive versions of the same cell lineage will capitalize on cell renewal properties while minimizing malignancy risk.
Statement of Benefit to California: 
Bone marrow transplantation saves the lives of millions with leukemia and other diseases including genetic or immunologic blood disorders. California has over 15 centers serving the population for bone marrow transplantation. While bone marrow transplantation can be seen as a standard to which all stem cell therapies should aspire, there still remains the difficulty of finding matched donors, complications such as graft versus host disease, and the recurrence of malignancy. While cord blood has provided another donor source of stem cells and improved engraftment, it still requires pooling from multiple donors for sufficient cell numbers to be transplanted, which may increase transplant risk. By understanding how to reprogram blood vessels (such as those in the umbilical cord) for production of blood stem cells (as it once did during human development), it could eventually be possible to bank umbilical cord vessels to provide a patient matched reproducible supply of pure blood stem cells for the entire life of the patient. Higher numbers of cells, and the ability to grow cells from matched donors (or the patients themselves) will increase engraftment and decrease rejection of bone marrow transplantation. In addition, the proposed work will introduce a new approach to engineering human cells. The ability to turn back the clock to near mature cell specific stages without going all the way back to early embryonic stem cell stages will reduce the risk of malignancy.
Progress Report: 
  • We aim to understand how blood stem cells develop from blood vessels during development. We are also interested in learning whether the blood-making program can be turned back on in blood vessel cells for blood production outside the human body. During the past year we have been able to extract and culture blood vessel cells that once had blood making capacity. We have also started experiments that will help uncover the regulation of the blood making program. In addition, we have developed tools to help the process of understanding whether iPS technology can "turn back time" in mature blood vessels and turn on the blood making program.
Funding Type: 
Early Translational I
Grant Number: 
TR1-01273
Investigator: 
ICOC Funds Committed: 
$6 649 347
Disease Focus: 
Blood Disorders
Immune Disease
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 
The primary aim of this project is to develop treatments for incurable diseases of the blood and immune system. X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi anemia (FA) are two blood diseases where mutations in a single gene results in the disease. XSCID, more commonly known as the “bubble boy” disease, is characterized by a complete failure of the immune system, and typically results in early childhood fatality. The most common treatment for X-SCID is bone marrow transplant using a matched sibling donor. Unfortunately, the lack of suitable donors limits the application of this treatment. In 2000, the first gene therapy "success" resulted in X-SCID patients with a functional immune system. These trials were stopped when it was discovered that several patients in one trial had developed lymphoma, a blood related cancer resulting from unintended consequences of the therapy. FA is a disease where the stability of the genome is compromised and results in premature cell death and lethal anemia. Gene therapy trials for such patients have been largely unsuccessful due to the inability to culture the cells long enough for the correction of the gene. Like XSCID there is a shortage of suitable bone marrow donors for patients, thus development of treatments via other methods is warranted. From this study and others we have learned 1) gene therapy can work to cure certain diseases, 2) adequate safeguards must be developed to prevent unintended cancer formation, and 3) we need better sources of matched cells and tissues to avoid the problems of rejection. Our proposal will be using one of the most exciting new developments in regenerative medicine, that is the ability to reprogram a patient’s skin, or even hair follicle back to an induced pluripotent stem (iPS) cell, which is similar to embryonic stem cells, without involving embryo destruction. The iPS cell is a good candidate for repair of the specific genetic defects that cause diseases like X-SCID and FA. The reprogrammed, genetically corrected cells are a perfect match for transplantation therapy since they come from the patient. At this stage the corrected cells will be augmented with additional safety factors that work to avoid the downstream potential for cancer. These safe and genetically corrected cells will then be coaxed back into the cells that form the blood and immune systems and used for transplant therapy. In this work we will be using mouse models that mimic the human diseases of X-SCID and FA and are amenable to treatment with human hematopoietic stem cells. We will be working with human patient and disease-specific cells to demonstrate the feasibility and evaluate the safety in a pre-clinical setting to advance these pioneering new techniques that combine the latest developments in regenerative medicine and gene therapy. Our proposed work will also benefit the successful stem cell based therapies for many other diseases like Parkinson’s and diabetes.
Statement of Benefit to California: 
The idea that embryonic stem cells (ES cells) have the ability to differentiate into a variety of cell types, tissues, and organs, opens the possibility of tissue engineering, replacement, and cell transplant therapies to cure diseases ranging from Parkinson’s, Alzheimer’s, diabetes, blood disorders and a host of other debilitating disorders. Rarely comes along a new technology that has the potential to make such a major impact on human health. Recently researchers have discovered methods to reprogram adult fibroblasts and skin cells back into a cell referred to as induced pluripotent stem cell (iPS) that appears to be indistinguishable from the pluripotent ES cell. This is accomplished without the need for embryo destruction and offers great potential to alleviate the problems of immune rejection in cell or tissue transplantation by allowing a patient’s own cells to be reprogrammed, expanded then used in therapeutic applications. The principle aim of this proposal is to develop new technologies that can be used to treat two specific devastating hematological disorders X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi Anemia (FA). Both are rare genetic diseases, and both have devastating effects on the immune and blood systems. The successful development of therapies for these diseases will have an obvious and direct effect on the patients and their families affected by these diseases. From a broader perspective, the establishment of these regenerative medicine techniques has the potential to treat a vast array of disease like Parkinson’s, Alzheimer’s, diabetes and other blood disorders like thalassemia, Sickle cell anemia, and hemophilia. These diseases all have devastating effects on the patients afflicted, but they also place a tremendous burden on the State in terms of health care cost. Ever more, we need to spend state resources wisely and finding ways to reduce the continually increasing cost of long-term medical care is critical. The work proposed here seeks to do just that by creating outright cures for diseases that if left untreated require substantial and prolonged medical expenditures and incredible suffering for the patients and their families. In other regards keeping the state of California at the forefront of medical breakthroughs and strengthening our biomedical and biotechnology industries. We are a leading force in these fields, not only across the nation but also worldwide.
Progress Report: 
  • The primary aim of this project is to develop treatments for incurable diseases of the blood and immune system. X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi anemia (FA) are two blood diseases where mutations in a single gene results in the disease. XSCID, more commonly known as the “bubble boy” disease, is characterized by a complete failure of the immune system, and typically results in early childhood fatality. The most common treatment for X-SCID is bone marrow transplant using a matched sibling donor. Unfortunately, the lack of suitable donors limits the application of this treatment. In 2000, the first gene therapy "success" resulted in X-SCID patients with a functional immune system. These trials were stopped when it was discovered that several patients in one trial had developed lymphoma, a blood related cancer resulting from unintended consequences of the therapy. FA is a disease where the stability of the genome is compromised and results in premature cell death and lethal anemia. Gene therapy trials for such patients have been largely unsuccessful due to the inability to culture the cells long enough for the correction of the gene. Like XSCID there is a shortage of suitable bone marrow donors for patients, thus development of treatments via other methods is warranted.
  • From this study and others we have learned: 1) gene therapy can work to cure certain diseases, 2) adequate safeguards must be developed to prevent unintended cancer formation, and 3) we need better sources of matched cells and tissues to avoid the problems of rejection.
  • We proposed to reprogram a patient’s skin, or even hair follicle back to an induced pluripotent stem (iPS) cell, which is similar to embryonic stem cells, without involving embryo destruction. The iPS cell is a good candidate for repair of the specific genetic defects that cause diseases like X-SCID and FA. We have reprogrammed many patients cells to generate iPS. More importantly, we have gotten early hints of success in making hematopoietic stem cells and other blood cells from them. We have also started to make iPS cells from both X-SCID patients.
  • The primary aim of this project is to develop treatments for incurable diseases of the blood and immune system. X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi anemia (FA) are two blood diseases where mutations in a single gene results in the disease. XSCID, more commonly known as the “bubble boy” disease, is characterized by a complete failure of the immune system, and typically results in early childhood fatality. The most common treatment for X-SCID is bone marrow transplant using a matched sibling donor. Unfortunately, the lack of suitable donors limits the application of this treatment. In 2000, the first gene therapy "success" resulted in X-SCID patients with a functional immune system. These trials were stopped when it was discovered that several patients in one trial had developed lymphoma, a blood related cancer resulting from unintended consequences of the therapy. FA is a disease where the stability of a patients genome is compromised and results in premature cell death and lethal anemia. Gene therapy trials for such patients have been largely unsuccessful due to the inability to culture the affected cells long enough for the correction of the gene. Like XSCID there is a shortage of suitable bone marrow donors for patients, thus development of treatments via other methods is warranted.
  • From this study and others we have learned: 1) gene therapy can work to cure certain diseases, 2) adequate safeguards must be developed to prevent unintended cancer formation, and 3) we need better sources of matched cells and tissues to avoid the problems of rejection.
  • Our approach starts with a patient’s skin, hair follicle or other easily accessible adult cell/tissue sample and employs a newly developed and robust technique to safely reprogram these cells back to an induced pluripotent stem (iPS) cell fate, which is similar to that of embryonic stem cells in potential, but is patient specific thereby avoiding downstream problems of immune rejection. The iPS cell is a good candidate for repair of the specific genetic defects that cause diseases like X-SCID and FA. We have successfully reprogrammed cells from human patients of each of these diseases to generate iPS cell lines. We are employing the latest technology to perform genetic correction of these cells. In parallel we are advancing the state-of-the-art in developing reliable methods to direct the differentiation of these disease corrected stem cells into the appropriate therapeutic cell types capable of reconstituting the blood and immune systems and thereby effecting cures for these hematological diseases.
  • The primary aim of this project is to develop treatments for incurable diseases of the blood and immune system. X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi anemia (FA) are two blood diseases where mutations in a single gene results in the disease. XSCID, more commonly known as the “bubble boy” disease, is characterized by a complete failure of the immune system, and typically results in early childhood fatality. The most common treatment for X-SCID is bone marrow transplant using a matched sibling donor. Unfortunately, the lack of suitable donors limits the application of this treatment. In 2000, the first gene therapy "success" resulted in X-SCID patients with a functional immune system. These trials were stopped when it was discovered that several patients in one trial had developed lymphoma, a blood related cancer resulting from unintended consequences of the therapy. FA is a disease where the stability of a patients genome is compromised and results in premature cell death and lethal anemia. Gene therapy trials for such patients have been largely unsuccessful due to the inability to culture the affected cells long enough for the correction of the gene. Like XSCID, there is a shortage of suitable bone marrow donors for patients, thus development of treatments via other methods is warranted.
  • From this study and others we have learned: 1) gene therapy can work to cure certain diseases, 2) adequate safeguards must be developed to prevent unintended cancer formation, and 3) we need better sources of matched cells and tissues to avoid the problems of rejection.
  • Our approach starts with a patient’s skin, hair follicle or other easily accessible adult cell/tissue sample and employs a newly developed and robust technique to safely reprogram these cells back to an induced pluripotent stem (iPS) cell fate, which is similar to that of embryonic stem cells in potential, but is patient specific thereby avoiding downstream problems of immune rejection. The iPS cell is a good candidate for repair of the specific genetic defects that cause diseases like X-SCID and FA. We have successfully reprogrammed cells from human patients of each of these diseases to generate iPS cell lines. We are employing the latest technology to perform genetic correction of these cells. In parallel we are advancing the state-of-the-art in developing reliable methods to direct the differentiation of these disease corrected stem cells into the appropriate therapeutic cell types capable of reconstituting the blood and immune systems and thereby effecting cures for these hematological diseases.
  • This project is focused on developing treatments for incurable diseases of the blood and immune system. X-linked Severe Combined Immunodeficiency (X-SCID) and Fanconi anemia (FA) are two blood diseases where mutations in a single gene results in the disease. XSCID, more commonly known as the “bubble boy” disease, is characterized by a complete failure of the immune system, and typically results in early childhood fatality. The most common treatment for X-SCID is bone marrow transplant using a matched sibling donor. Unfortunately, the lack of suitable donors limits the application of this treatment. In 2000, the first gene therapy "success" resulted in X-SCID patients with a functional immune system. These trials were stopped when it was discovered that several patients in one trial had developed lymphoma, a blood related cancer resulting from unintended consequences of the therapy. FA is a disease where the stability of a patients genome is compromised and results in premature cell death and lethal anemia. Gene therapy trials for such patients have been largely unsuccessful due to the inability to culture the affected cells long enough for the correction of the gene. Like XSCID, there is a shortage of suitable bone marrow donors for patients, thus development of treatments via other methods is warranted. From this study and others we have learned: 1) gene therapy can work to cure certain diseases, 2) adequate safeguards must be developed to prevent unintended cancer formation, and 3) we need better sources of matched cells and tissues to avoid the problems of rejection.
  • Our approach starts with a patient’s skin, hair follicle or other easily accessible adult cell/tissue sample and employs newly developed and robust techniques to safely reprogram these cells back to an induced pluripotent stem (iPS) cell fate, which is similar to that of embryonic stem cells in potential, but is patient specific thereby avoiding downstream problems of immune rejection. The iPS cell is a good candidate for repair of the specific genetic defects that cause diseases like X-SCID and FA. To date, we have successfully reprogrammed cells from human patients of each of these diseases to generate iPS cell lines. We have also had success employing the latest technology to perform genetic correction of these cells, effectively repairing the DNA mutations that cause the diseases. In parallel we are advancing the state-of-the-art in developing reliable methods to direct the differentiation of these disease corrected stem cells into the appropriate therapeutic cell types capable of reconstituting the blood and immune systems and thereby effecting cures for these hematological diseases.
Funding Type: 
Transplantation Immunology
Grant Number: 
RM1-01733
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 403 557
Disease Focus: 
Blood Disorders
Immune Disease
Muscular Dystrophy
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Blood and immune cells originate and mature in the bone marrow. Bone marrow cells are mixtures of blood cells at different stages of development, and include rare populations of blood-forming stem cells. These stem cells are the only cells capable of generating the blood system for the life of an individual. Bone marrow transplants (BMT) have been performed > 50 years, to replace a diseased patient’s blood system with that of a donor. Unfortunately, BMT have associated dangers which make the procedure high risk. Major risks include a syndrome called graft-versus-host disease (GvHD) which results when the donor’s mature blood cells attack the organs of the host, and toxicity from the treatments (radiation and chemotherapy) required to permit the donor cells to take in the recipient. These risk factor limit the use of BMT to only immediate life-threatening diseases. If made safer, BMT could cure many other debilitating diseases. In addition to being curative of blood cancers and non-malignant blood diseases (such as sickle-cell anemia), these transplants can cure autoimmune diseases, such as juvenile (type I) diabetes and multiple sclerosis. In addition, simultaneous BMT with organ transplants induces “tolerance” to the new organ, meaning the recipient will not reject the graft because the new blood system provides continuous proteins to re-train the recipient immune system not to attack it. This establishment of tolerance eliminates the need for drugs that suppress the immune system. In efforts to make BMT safer, our research has focused on isolating the blood stem cells away from the other bone marrow cells because transplants of pure stem cells do not cause GvHD. We developed the methods to purify the blood stem cells from mouse and human blood forming sources and showed in mice that transplants of blood stem cells can cure autoimmune disease and induce tolerance to solid organ transplants. However, this technology has not been tested in human clinical trials because safer methods must be developed that permit the stem cells to engraft in recipients. Our studies in mice show that we can replace the toxic drugs and radiation used to prepare recipients for BMT with non-toxic proteins that target the cells responsible for rejection of blood stem cells. The goal of this study is to translate this technology from mice to patient clinical trials. If successful, the studies will open the door to the use of blood stem cell transplants to the many thousands of patients who could benefit from this approach. The science behind achieving blood stem cell engraftment by the methods we propose look toward the future when blood stem cells and other tissues will be developed from pluripotent stem cells (ES, NT and iPS). We envision that the blood stem cells will induce tolerance to tissues derived from the same pluripotent stem cell line, in the same way that adult blood stem cells induce tolerance to organs from the same living donor.
Statement of Benefit to California: 
The science and the preclinical pathway to induce human immune tolerance in patients with degenerative diseases so that new blood and tissue stem cells can regenerate their lost tissues: For stem cell biology to launch the era of regenerative medicine, stem cells capable of robust and specific regeneration upon transplantation must be found, and methods for safe patient administration must be developed. In the cases where cell donation cannot come from the host, immune responses will reject the donor stem cells. Successful transplants of blood-forming stem cells (HSC) leads to elimination immune cells that reject organ grafts from donors. While bone marrow or cord blood transplants contain immune cells called T cells that will attack the host in a potentially lethal graft against host immune reaction, purified HSC do not do this. Pluripotent stem cells (ES, NT, iPS) can make all cell types in the body and provide a shortcut to find tissue and organ stem cells. Just as co-transplants of adult HSC prevent rejection of organs from the same donor, co-transplants of HSC derived from pluripotent cells should protect tissues derived from the same pluripotent line. Attack by a patient's blood system against one’s own organs cause the syndromes of autoimmune disease including juvenile diabetes, multiple sclerosis, and lupus. Transplanted HSC from donor mice genetically resistant to these diseases end the autoimmune attack permanently. We have in mice, substituted minimally toxic antibodies for toxic chemoradiotherapy to prepare the host for HSC transplants. Now it is time to take these advances to humans, with human immune cell and HSC-targeting antibodies. Long-term potential benefits to the state of California and its residents: The justification for Proposition 71 was to establish in California centers of research not funded adequately in the areas of stem cell biology and regenerative medicine. This research, if successful, is the platform for the application of stem cell biology to regenerative medicine. The costs for long-term immune suppression to patients who receive organ transplants are enormous, both in terms of quality of life, even survival, and healthcare resources. Add to that the lifetime costs of insulin to treat juvenile diabetes, with the inevitable premature diseases of compromised blood vessels and organs, and the shortened lifespan of patients. Add to that the costs to lives and the healthcare system of lupus, of multiple sclerosis, of other autoimmune diseases like juvenile and adult rheumatoid arthritis and scleroderma, and of muscular dystrophy, to mention a few, and the value to Californians and people everywhere is obvious. If our studies are successful, and if the clinical trials were first done in California, our citizens will have the first chance at successful treatment. Further, if these studies are successful - new antibodies, if produced by CIRM funds, will generate royalties which eventually will return to the state.
Progress Report: 
  • The successful transplantation of blood forming stem cells from one person to another can alter the recipient immune system in profound ways. The transplanted blood forming cells can condition the recipient to accept organs from the original stem cell donor without the need for drugs to suppress their immune system; and such transplantations can be curative of autoimmune diseases such as childhood diabetes and multiple sclerosis. Modification of the immune system in these ways is called immune tolerance induction.
  • Unfortunately, the current practice of blood stem cell transplantation is associated with serious risks, including risk of death in 10-20% of recipients. It has been a long-standing goal of investigators in this field to make transplantations safer so that patients that must undergo this procedure have better outcomes, and so that patients who need an organ graft or that suffer from an autoimmune disorder can be effectively treated by this powerful form of cellular therapy. The major objectives of our proposal are to achieve this goal by developing methods to prepare patients to accept blood forming stem cell grafts with reagents that specifically target cell populations in recipients that constitute the barriers to engraftment, and to transplant only purified blood forming stem cells thereby avoiding the potentially lethal complication call graft-vs-host disease.
  • The proposal has four Specific Aims. Aims 1 and 2 focus on development of biologic agents that specifically target recipient barrier cells. Aims 3 and 4 propose to test the reagents and approaches developed in the first two aims in mouse models to induce tolerance to co-transplanted tissues and to cure animals with Type 1 diabetes mellitus or multiple sclerosis. These aims have not changed in this reporting period.
  • One parameter of success in this project is the development of one or more biologic reagents that can replace toxic radiation and chemotherapy that can be used in human clinical trials by the end of the third year of funding (Aim 2). In this regard, significant progress has been made in the last year. A reagent critical to the success of donor blood forming stem cell engraftment is one that targets and eliminates the stem cells that already reside in the recipients. Recipient blood stem cells block the ability of donor stem cells to take. In our prior mouse studies we determined that a protein (antibody) that specifically targets a molecule on the surface of blood forming stem cells called CD117 is capable of eliminating recipient blood stem cells thus opening up special niches and allowing donor stem cells to engraft. This antibody was highly effective in permitting engraftment of purified donor blood stem cells in mice that lack a functional immune system. In this application we proposed to develop and test reagents that could target and eliminate human blood forming stem cells by targeting human CD117. This year we have identified and tested such an antibody which is manufactured by a third party. This anti-CD117 antibody has been evaluated in early clinical trials for an indication separate from our proposed use and appears to be non-toxic. In mice that we generated to house a human blood system, the antibody was capable eliminating the human blood forming stem cells. We plan to pursue the use of this reagent in a clinical trial as a non-toxic way to prepare children with a disease called severe combined immunodeficiency (SCID) for transplantation. Without a transplant children with SCID will die. The use of the anti-CD117 antibody and transplantation of purified blood forming stem cells has the potential to significantly reduce the complications of such transplants and improve the outcomes for these patients. The trial will be the first step to using this form of targeted therapy and serve as a pioneering study for all indications for which a blood forming stem cell transplant is needed, including the induction of immune tolerance.
  • The transplantation of blood forming stem cells from one individual to another can alter the recipient immune system in profound ways. Transplanted blood forming cells can condition the recipient to accept organs from the original stem cell donor without the need for drugs to suppress their immune system. Such transplantations can also be curative of autoimmune diseases such as childhood diabetes and multiple sclerosis. Modification of the immune system in these ways is called immune tolerance induction.
  • The major goal of this project is to enable the use of blood forming stem cell transplantation for the purpose of immune tolerance induction without unwanted side effects. The current practice of blood stem cell transplantation is associated with serious risks, including risk of death in 10-20% of recipients due to complications of transplant conditioning and graft-versus-host disease. We aim to abolish or reduce the risks of these transplantations so that this curative form of stem cell therapy can safely treat patients who need an organ graft or who suffer from an autoimmune disorder. To achieve our goals, we proposed the development of methods to prepare patients to accept blood forming stem cell grafts with reagents that specifically target recipient cell populations that constitute the barriers to engraftment, and to transplant only purified blood forming stem cells, thereby avoiding graft-versus-host disease.
  • The proposal has four Specific Aims. Aims 1 and 2 focus on development of biologic agents that specifically target recipient barrier cells. Aims 3 and 4 propose testing the reagents and approaches developed in the first two aims in mouse models to induce tolerance to co-transplanted tissues and to cure animals with muscular dystrophy, Type 1 diabetes mellitus and multiple sclerosis. These aims have not changed in this reporting period.
  • In this reporting period, significant progress has been made in the first three aims. In prior years we identified a biologic reagent that has the potential to replace toxic radiation and chemotherapy. Radiation and chemotherapy are used in transplantation to eliminate the blood forming stem cells of recipients because recipient stem cells block the ability of donor cells to take. The novel reagent we have studied is a protein, called a monoclonal antibody, which differs from radiation and chemotherapy because it specifically targets and eliminates recipient blood stem cells. This antibody reagent recognizes a molecule on the surface of blood stem cells called CD117. In years 1 and 2 we began testing of an anti-human CD117 (anti-hCD117) antibody in mice. Mice were engrafted with human blood cells and we showed that this antibody safely and specifically eliminated the human blood forming cells. These studies were proof-of-concept that the antibody is appropriate for use in human clinical trials.
  • This last year we were awarded a CIRM Disease Team grant to move the testing of this anti-hCD117 from the experimental phase in mice to a clinical trial for the treatment of children with a disease call severe combined immunodeficiency (SCID), also known as the “bubble boy” disease. Children with SCID are missing certain types of white blood cells (lymphocytes) so they cannot defend themselves from infections. Without a transplant, children with SCID will die. The use of the anti-CD117 antibody and transplantation of purified blood forming stem cells has the potential to significantly reduce the complications of such transplants and improve the outcomes for these patients. The use of the anti-CD117 antibody and transplantation of purified blood forming stem cells has the potential to significantly reduce the complications of such transplants and improve the outcomes for these patients. The trial will be the first step to using this form of targeted therapy and serve as a pioneering study for all indications for which a blood forming stem cell transplant is needed, including the induction of immune tolerance.
  • In the last year we have moved forward with the purification of skeletal muscle stem cells based upon labeling and sorting of primitive muscle cells that express an array of molecules on the cell surface. We have also transplanted a special strain of mice (mdx) that are a model for muscular dystrophy with blood forming stem cells from normal mouse donors. In the coming year we will perform simultaneous transplants of blood forming stem cells and skeletal muscle stem cells from normal donor mice into the mdx mice. We will determine if the blood stem cells permit the long-term survival of the muscle stem cells in recipients transplanted across histocompatibility barriers. Our ultimate goal is to achieve long-term recovery of muscle cell function in the recipients of these co-transplantations.
  • The transplantation of blood forming stem cells from one individual to another is widely used to treat patients with otherwise incurable cancers. Because such transplantations alter the recipient immune system in profound ways there are many other applications for this powerful form of therapy. The studies proposed in this grant focused on the use of blood stem cell transplantation for the purpose of immune tolerance induction. Tolerance induction in this setting means that transplantation of blood stem cells trains the body of a recipient to accept organs from same stem cell donor without the need for drugs to suppress their immune system. Blood stem transplantations can also reverse aberrant immune responses in individuals with autoimmune diseases such as childhood diabetes and multiple sclerosis.
  • In this project we sought to develop new ways to perform blood stem cell transplants to make the procedure safer and therefore more widely useable for a broad spectrum of patients. Transplants can be dangerous and sometimes fatal. Serious complications are caused by the toxic chemotherapy or radiation which are used to permit stem cells to engraft, and by a syndrome called graft-versus-host disease. Our research has aimed to replace the toxic treatments by testing novel reagents that more specifically target and eliminate the cells in recipients that constitute the barriers to stem cell engraftment. Furthermore, we perform transplantations of purified blood forming stem cells, and thus are able to avoid the problem of graft-versus-host disease which is caused by non-stem cell “passenger” immune cells in the donor grafts.
  • The proposal has four Specific Aims. Aims 1 and 2 focus on development of biologic agents that specifically target recipient barrier cells. Aims 3 and 4 propose testing the reagents and approaches developed in the first two aims in mouse models to induce tolerance to co-transplanted tissues and to cure animals with muscular dystrophy, Type 1 diabetes mellitus and multiple sclerosis. These aims have not changed in this reporting period.
  • Our prior reports highlighted our progress in Aim 2, which is now complete. Aim 2 focused on the identification and testing of an antibody directed against a molecule called CD117 present on surface of human blood stem cells. We demonstrated that this antibody can safely target and eliminate human blood stem cells in mice that had been previously engrafted with human cells. Based upon these studies we were awarded a CIRM Disease Team Grant, which will test this anti-human CD117 antibody in a clinical trial for the treatment of children with severe combined immune deficiency (SCID), also known as the “bubble boy” disease. Children with SCID are missing certain types of white blood cells (lymphocytes) so they cannot defend themselves from infections. Without a transplant, SCID patients usually die before the age of two. Our proposed clinical study has the potential to significantly improve the success of transplants for these patients. This clinical trial will be a first to test a reagent that specifically targets recipient stem cells to clear niche space and allow replacement therapy by healthy donor stem cells.
  • In the last year we have continued to make significant progress on Aims 1, 3 and 4. Aim 1 proposed to study how to improve blood stem cell engraftment using novel agents in mice that have intact immune systems. The anti-CD117 antibody discussed above works well in recipients that lack lymphocytes but not recipients with normal immune function. We have tested the anti-CD117 antibody in mice that lack more defined lymphocyte subsets to narrow down which lymphocyte type must be neutralized or eliminated. We have also tested novel reagents that inhibit the activity of specific immune cells and observed a stronger effect of the anti-CD117 antibody when co-administered with these reagents. For Aims 3 and 4, we have successfully achieved our goal of performing blood stem cell transplants that result in the stable mixing of blood cells between donor and recipients (called partial chimerism). For Aim 3, recipients are from a specialized mouse strain that models muscular dystrophy (MDX mice). We have transplanted purified skeletal muscle stem cells (SMSC) and observed engraftment of SMSC in MDX mice injected with genetically-matched SMSC. The next step is to test if co-transplants of blood stem cells plus SMSC from genetically mismatched donors will permanently engraft and expand in MDX recipients. For Aim 4, two mouse models are studied: (1) NOD mice which model childhood diabetes, and (2) mice that develop multiple sclerosis. We can successfully block the progression of disease in these animals with blood stem cell transplants. Our next steps are to apply the therapies developed in Aim 1 to these disease models. In the post-award period we will continue to carry out studies testing the novel approaches developed here in models of tolerance induction.
Funding Type: 
Transplantation Immunology
Grant Number: 
RM1-01730
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$958 808
Disease Focus: 
Blood Disorders
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Closed
Public Abstract: 
One of the great promises of stem cell research is that it will one day be possible to prepare replacement cells or organs from stem cells such as embryonic stem cells, which can be transplanted to patients to substitute for diseased or defective patient tissues or organs. Unfortunately, the immune system reacts against, and rejects, transplanted tissues that are not perfectly matched with the recipient. A promising approach around this problem is a two step procedure, in which a patient is first transplanted with blood stem cells of a specific type, and later with replacement tissues or cells derived from the same embryonic stem cells as the blood stem cells. If the blood cell transplant is successful, the patient’s blood cells will forever after be composed of a mixture of their own blood cells and the donor blood cells (“chimerism”). It is known that blood cell chimerism induces the recipient to be accept diverse types of grafts of the same source as the blood cells. Thus, the blood cell graft prepares the recipient to accept other types of grafts derived from the same stem cells. Unfortunately, blood stem cell grafts are themselves subject to a specific type of immune rejection, mediated by natural killer (NK) cells. Hence, successful application of the two step procedure requires the development of methods to prevent NK cells from rejecting blood cell grafts. We have developed evidence that NK cells can be induced to become tolerant of mismatched blood cell grafts. We propose studies to develop a general procedure to induce tolerance of a recipient’s NK cells to mismatched blood cell grafts. Using an experimental model, we will test whether the procedure facilitates transplantation of blood cells derived from embryonic stem cells, the generation of blood cell chimerism, and the subsequent transplantation of other tissues in a two step procedure.
Statement of Benefit to California: 
The proposed research is designed to provide novel methods to facilitate therapeutic transplantation of stem cell derived cells and tissues to patient’s suffering from numerous disorders and diseases. Such approaches will ultimately benefit millions of Californians suffering from diabetes, heart disease, neurodegenerative diseases, etc. Breakthroughs in stem cell research in California will also generate new industries, reducing joblessness and bolstering the California economy.
Progress Report: 
  • Our plan is to find ways to facilitate transplants of stem cell-derived cells to genetically different recipients. We propose to inactivate the rejection capability of natural killer cells, a white blood cell type that can reject transplanted cells. To explore this we started with a mouse model. Previously we generated evidence that there are one or more cell types in normal mice can inactivate the rejection capacity of natural killer cells. Our first aim is to identify that cell type to see it can be injected into mice to inactivate the natural killer cells. In the last year we have generated evidence that the relevant cell type is a non-blood cell type. We will now test various non-blood cell types to see which ones have this capability. The hope is that once the cell type has been identified, it could be generated from stem cells and injected into patients to facilitate transplants of other cell types derived from the same stem cells.
  • Our plan is to find ways to facilitate transplants of stem cell-derived cells to genetically different recipients. We propose to inactivate the rejection capability of natural killer cells, a white blood cell type that can reject transplanted cells. To explore this we started with a mouse model. Previously we generated evidence that there are one or more cell types in normal mice can inactivate the rejection capacity of natural killer cells. Our first aim is to identify that cell type to see it can be injected into mice to inactivate the natural killer cells. In the last year we discovered that the relevant cells include both blood cell types and non blood cell types. We showed however, that tolerance induced by non-blood cell types induces a more stable type of tolerance than that induced by blood cell types. We went on to develop a system in live mice to test subtypes of cells that can induce tolerance. Using this system, we could show that a heterogeneous mixture of blood cell types could induce tolerance. The system is suitable for testing specific blood cell, or non blood cell, types for their capacity to induce tolerance. We will undertake those studies in the coming months. The hope is that once the cell type has been identified, it could be generated from stem cells and injected into patients to facilitate transplants of other cell types derived from the same stem cells.
  • Stem cell therapy involves transfer of stem cells to patients. Transferring stem cells from a donor to a patient holds particular promise, because the stem cells may be reliably modified to rectify a specific defect and restore a particular function. This approach is limited by the patient’s immune response, which may reject the foreign transplant. Immune suppressive drugs can be used to prevent rejection of the stem cell, but these drugs leave patients sensitive to infections. We aim to find new, less debilitating methods to facilitate transplantation of foreign stem cell derived tissues. One approach is to establish a state of immune tolerance in the patient, by transplanting blood cells to generate blood cell mixing, called chimerism— that the patient tolerates. Once that is successful, stem cells of other tissues will also be tolerated, as long as they are from the same donor as the donor blood cells. Our efforts have focused on enabling patients to accept foreign blood cells—the first step in this approach. Natural killer cells are immune cells that are known to reject foreign blood cells, when the donor cells are mismatched at genes that control tissue rejection. We have shown that natural killer cells can be rapidly converted to a tolerant state when exposed to specific foreign cells from a donor. Subsequently, they will ignore transplants from the same donor. These findings suggested we could develop methods to readily prevent rejection of foreign blood cells by natural killer cells, but we also learned that this tolerance is fragile: when infections occurred, the tolerance could be reversed and the donor cells rejected. If this occurred after stem cell therapy, the donor stem cells would be rejected, abrogating the benefit of stem cell therapy. However, we also learned that this outcome did not occur in all circumstances. We learned that the fragile state of tolerance occurred when natural killer cells were exposed to foreign blood cells, but a distinct or deeper state of tolerance occurred when NK cells were exposed to other types of foreign cells, not of the blood cell lineages. In that case, tolerance was much less fragile and was sustained even when infections occurred. Our research is geared to identifying the key cell types that induce a deeper and less fragile form of tolerance of natural killer cells, in order to improve the effectiveness of therapeutic stem cell therapy.
Funding Type: 
Transplantation Immunology
Grant Number: 
RM1-01709
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$1 746 684
Disease Focus: 
Blood Disorders
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
The research proposed in this project has very high potential to identify new medications to boost the natural ability of stem cells to prevent rejection of transplanted organs. This is a very important goal, because patients that receive a life-saving transplanted organ must take toxic medications that increase their risk for cancer and serious infections. Experimental clinical trials have recently shown that stem cells given to patients at the same time as they receive their transplanted organ can engraft in the patient and prevent rejection of the transplanted organ, without the need to take immunosuppressive medications. The problem though is that the stem cells don't last forever; they are eventually rejected by the patient's own immune system. A promising target to prevent rejection of stem cells in patients is a group of primitive molecules that are receptors on stem cells, as well as many other cells in the body. These primitive receptors are called innate immune receptors and they provide the trigger for activation of a cascade of mechanisms that lead to rejection of the stem cells. If the trigger is not pulled, then the stem cells will not be rejected. Therefore, our proposal focuses on how to block activation of the rejection cascade so that stem cells are able to engraft in the patient and prevent rejection of transplanted organs, without the life-long use of toxic medications. We have extensive experience studying innate immune receptors and transplantation and therefore are poised to make significant advances in our understanding of how stem cells are rejected by signals that depend on innate immune receptors. Furthermore, once we identify which innate immune receptors are relevant, targeted rationale blockade of these receptors can be proposed.
Statement of Benefit to California: 
The proposed research will benefit the State of California and its residents by providing important knowledge about new ways to prevent rejection of transplanted organs. Currently, patients with transplanted organs must take life-long toxic medications to prevent rejection of their organs. This proposal will help develop ways to avoid the use of these toxic medications, while allowing life-saving organ transplants to survive in their new host. The use of stem cells in recipients of solid organ transplants is the first new breakthrough in decades for transplantation and therefore it is very important to try to optimize the use of stem cells to allow the survival of transplanted organs without toxic immunosuppressive medications.
Progress Report: 
  • Recent studies conducted first in animals and subsequently confirmed in humans have shown that tolerance to solid organ transplants can be achieved using donor-derived hematopoietic stem cells (HSCs). HSCs can induce tolerance by embedding in the recipient’s thymus. Once in the thymus they cause the deletion or inhibition of recipient cells that would otherwise cause rejection of a transplanted organ from the same donor. The coexistence of donor and host hematopoietic cells is called mixed chimerism and as long as the donor cells remain in the host, an allograft from the donor can be accepted without the need for immunosuppression.
  • Although many studies have shown that mixed chimerism can be obtained, donor tissue can still reject because the host responses to engrafted organs are not completely suppressed. Therefore, before HSC strategies can be widely used, additional refinements are needed to prevent activation of host responses. A logical approach, based on recent new information about the early activation events, involves targeting primitive receptors that are initial triggers of adaptive immunity – pattern recognition receptors (PRRs).
  • Pattern recognition receptors have recently been linked to activation of HSCs because it is known that HSCs undergo massive expansion and migration in inflammation. Two families of PRRs have been identified in HSCs - toll-like receptors (TLRs) and NOD-like receptors (NLRs). TLRs reside on cell membranes and NLRs are found within the cells HSCs. TLR/NLR-induced expansion and differentiation of HSCs results in their differentiation into activated cells that trigger rejection of donor cells (i.e., chimeric donor cells that would otherwise 'tolerize' host T cells are rejected). The end result of the PRR-induced activation of HSCs is loss of mixed chimerism and graft rejection. We have already shown that targeted blockade of specific PRRs can prevent ischemia-mediated tissue injury, inflammatory responses to the tissue injury, and also prolong survival of highly immunogenic allografts.
  • The overall objective of our project is to identify novel potential drug targets that promote HSC-mediated tolerance to transplanted solid organs. The idea is that signals mediated through PRRs interfere with HSC-mediated mixed chimerism and tolerance induction. We proposed to test our hypothesis in three interrelated aims. The first aim focused on testing the role of PRRs in the induction of tolerance. The second aim focused on the role of donor cells in the induction of host T cell unresponsiveness. The third aim focused on the role of HSC-mediated mixed chimerism on donor graft survival.
  • The first year of funding has already led to some important initial findings that are setting the stage for our understanding the role of hematopoietic stem cell induced tolerance. We believe that many, unavoidable, signals are activated during the course of HSC harvest and transplantation and that some of these signals reduce the ability of the transplanted HSCs to engraft in the host. Our initial findings suggest that if some of these signals are blocked, HSC engraftment, and transplant tolerance, can be enhanced. We are currently testing our initial exciting findings and progressing on the second and third aims of the study.
  • During the past funding period several significant advances were made towards each of the three aims of the proposal. We found that innate immune receptors were critically important to engraftment of hematopoietic stem cells and we have begun to understand how engraftment is enhanced in the absence of some of these receptors. We also discovered important aspects of the biology of the KO cells and how they might confer better engraftment. Our ongoing studies are focused on the mechanistic factors that lead to enhanced hematopoietic stem cell engraftment in our model.
  • Significant progress was made in the three aims of this project. Most important was the finding that we could markedly improve engraftment of foreign hematopoietic stem cells by removing certain receptors of the innate immune system from the donor stem cells. We have pursued an understanding of how cells without these innate immune receptors can be better at engraftment. It appears that T cells lacking these receptors are less able to proliferate in response to the foreign antigens.
Funding Type: 
New Cell Lines
Grant Number: 
RL1-00649
Investigator: 
ICOC Funds Committed: 
$1 737 720
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Autism
Blood Disorders
Rett's Syndrome
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Human embryonic stem cells (hESC) hold great promise in regenerative medicine and cell replacement therapies because of their unique ability to self-renew and their developmental potential to form all cell lineages in the body. Traditional techniques for generating hESC rely on surplus IVF embryos and are incompatible with the generation of genetically diverse, patient or disease specific stem cells. Recently, it was reported that adult human skin cells could be induced to revert back to earlier stages of development and exhibit properties of authentic hES cells. The exact method for “reprogramming” has not been optimized but currently involves putting multiple genes into skin cells and then exposing the cells to specific chemical environments tailored to hES cell growth. While these cells appear to have similar developmental potential as hES cells, they are not derived from human embryos. To distinguish these reprogrammed cells from the embryonic sourced hES cells, they are termed induced pluripotent stem (iPS) cells. Validating and optimizing the reprogramming method would prove very useful for the generation of individual cell lines from many different patients to study the nature and complexity of disease. In addition, the problems of immune rejection for future therapeutic applications of this work will be greatly relieved by being able to generate reprogrammed cells from individual patients. We have initiated a series of studies to reprogram human and mouse fibroblasts to iPS cells using the genes that have already been suggested. While induction of these genes in various combinations have been reported to reprogram human cells, we plan to optimize conditions for generating iPS cells using methods that can control the level of the “reprogramming” genes, and also can be used to excise the inducing genes once reprogramming is complete; thus avoiding unanticipated effects on the iPS cells. Once we have optimized the methods of inducing human iPS cells from human fibroblasts, we will make iPS cells from patients with 2 different neurological diseases. We will then coax these iPS cells into specific types of neurons using methods pioneered and established in our lab to explore the biological processes that lead to these neurological diseases. Once we generate these cell based models of neural diseases, we can use these cells to screen for drugs that block the progress, or reverse the detrimental effects of neural degeneration. Additionally, we will use the reprogramming technique to study models of human blood and liver disease. In these cases, genetically healthy skin cells will be reprogrammed to iPS cells, followed by introduction of the deficient gene and then coaxed to differentiate into therapeutic cell types to be used in transplantation studies in animal models of these diseases. The ability of the reprogrammed cell types to rescue the disease state will serve as a proof of principle for therapeutic grafting in
Statement of Benefit to California: 
It has been close to a decade since the culture of human embryonic stem (hES) cells was first established. To this day there are still a fairly limited number of stem cell lines that are available for study due in part to historic federal funding restrictions and the challenges associated with deriving hES cell lines from human female egg cells or discarded embryos. In this proposal we aim to advance the revolutionary new reprogramming technique for generating new stem cell lines from adult cells, thus avoiding the technical and ethical challenges associated with the use of human eggs or embryos, and creating the tools and environment to generate the much needed next generation of human stem cell lines. Stem cells offer a great potential to treat a vast array of diseases that affect the citizens of our state. The establishment of these reprogramming techniques will enable the development of cellular models of human disease via the creation of new cell lines with genetic predisposition for specific diseases. Our proposal aims to establish cellular models of two specific neurological diseases, as well as developing methods for studying blood and liver disorders that can be alleviated by stem cell therapies. California has thrived as a state with a diverse population, but the stem cell lines currently available represent a very limited genetic diversity. In order to understand the variation in response to therapeutics, we need to generate cell lines that match the rich genetic diversity of our state. The generation of disease-specific and genetically diverse stem cell lines will represent great potential not only for CA health care patients but also for our state’s pharmaceutical and biotechnology industries in terms of improved models for drug discovery and toxicological testing. California is a strong leader in clinical research developments. To maintain this position we need to be able to create stem cell lines that are specific to individual patients to overcome the challenges of immune rejection and create safe and effective transplantation therapies. Our proposal advances the very technology needed to address these issues. As a further benefit to California stem cell researchers, we will be making available the new stem cell lines created by our work.
Progress Report: 
  • Public Summary for: CIRM New Cell Line Project - Progress Report.
  • Our research team has been working over the last year on developing new human stem cell lines that are specifically useful for studying human diseases and developing new therapeutic strategies. Human embryonic stem (hES) cells were first established in 1998 and in the past decade have been shown to be capable to differentiating to a vast array of different cell types. This full developmental potential is termed pluripotency. Until recently these were the only established human cell type that could be robustly grown in the laboratory setting and still maintain full pluripotent developmental potential. In November of 1997, a new type of human pluripotent cell was created. By turning on a set of 4 genes, researchers succeeded in reprogramming human skin cells back into a cell type that appeared to have very similar properties and potential as the hES cell. These new stem cells are called induced pluripotent stem (iPS) cells in order to keep the name distinct from their embryonic derived counterpart. One of the scientific limitations of hES cells is the impracticality of generating patient or disease specific stem cell lines. This opportunity now becomes theoretically practical with the advent of human iPS cell line generation. We report here on significant progress demonstrating the practicality of generating disease-linked cellular models of human diseases.
  • We have identified 2 specific human neurological diseases that have a known, or strongly suggested genetic component, and have set about to generate disease-linked iPS cell lines. We have obtained skin cell samples from patients with these neurological diseases and have successfully reprogrammed them back to iPS cells. These disease-linked pluripotent stem cells have been carefully characterized and we have demonstrated that they do indeed behave very similar to existing hES cells and also to the genetically healthy control iPS cell lines that we have generated. Therefore the disease phenotype is not detrimental to reprogramming or proliferation as a stem cell. Furthermore, we have succeeded in coaxing these disease-linked iPS cells to turn into specific types of human neurons, the very cells that are suspected to be involved in the neurological disorders. We now have established a viable model for studying human neural disorders in the laboratory, and have already observed some potentially important functional differences between the disease-linked and control iPS generated neurons. In the coming year we will be evaluating the differences between the disease-linked and control neurons and investigating potential therapeutic approaches to stop or reverse the defects.
  • We have also been working on developing new methods for generating iPS cells that will make them more useful in clinical or pre-clinical settings where it is important that the original set of 4 genes used to reprogram the skin cells are removed once they have become iPS cells. Significant progress has been made in this regard and will be completed in the coming year. Looking forward we will also be applying this approach to generate human disease-linked iPS cells for specific hematological (blood) related disorders. The derivation of iPS-based models of hematological disorders will allow us develop gene therapy approaches to correct the disease causing defects and establish proof of principle for therapeutic approaches.
  • This research project is focused on developing new human stem cell lines that are specifically useful for studying human diseases and developing new therapeutic strategies. Human embryonic stem (hES) cells were first established in 1998 and in the past decade have been shown to be capable of differentiating to a vast array of different cell types. This full developmental potential is termed "pluripotency." Until recently these were the only established human cell types that could be robustly grown in the laboratory setting and still maintain full pluripotent developmental potential. In November 1997 a new type of human pluripotent cell was created. By turning on a set of 4 genes, researchers succeeded in reprogramming human skin cells back into a cell type that appeared to have very similar properties and potential as the hES cell. These new stem cells are called induced pluripotent stem (iPS) cells in order to keep the name distinct from their embryonic derived counterpart. One of the scientific limitations of hES cells is the impracticality of generating patient or disease specific stem cell lines. This opportunity now becomes theoretically practical with the advent of human iPS cell line generation. We report here on significant progress demonstrating the practicality of generating disease-linked cellular models of human diseases.
  • We have identified 2 specific human neurological diseases that have known, or strongly suggested, genetic components and have set about to generate disease-linked iPS cell lines. We have obtained skin cell samples from patients with these neurological diseases and have successfully reprogrammed them back to iPS cells. These disease-linked pluripotent stem cells have been carefully characterized and we have demonstrated that they do indeed behave very similar to existing hES cells and also to the genetically healthy control iPS cell lines that we have generated. Therefore, the disease phenotype is not detrimental to reprogramming or proliferation as a stem cell. Furthermore, we have succeeded in coaxing these disease-linked iPS cells to turn into specific types of human neurons, the very cells that are suspected to be involved in the neurological disorders. We now have established a viable model for studying human neural disorders in the laboratory, and have already observed some potentially important functional differences between the disease-linked and control iPS-generated neurons. Importantly, we have found defects in the function of disease-linked neurons that can be corrected in part following specific drug treatments. This discovery demonstrates the potential utility to use this method of modeling human diseases in the laboratory as a tool for understanding the detailed pathways, which might contribute to the development of the disease state and, importantly, as a target for screening potential therapeutic compounds that might be used to block or slow the progress of human neural disorders. In the coming year we will finalize our efforts on this project.
  • We have also succeeded in developing an improved method for the delivery of the reprogramming genes into the patient cells in order to become iPS cells. This method allows the reprogramming genes to be removed thus mitigating the potential for unwanted and potentially detrimental reactivation of these reprogramming genes subsequent to the iPS cell state. We have begun work using this new reprogramming methodology to generate iPS cell lines that are specifically linked to diseases of the blood and immune system. The new methodology appears to be working well and we anticipate completing the generation and characterization of these new disease-linked stem cell lines within the next year of this project.
  • This research project has been focused on developing new human stem cell lines that are specifically useful for studying human diseases and developing new therapeutic strategies. Human embryonic stem (hES) cells were first established in 1998 and in the past decade have been shown to be capable to differentiating of a vast array of different cell types. This full developmental potential is termed "pluripotency". Until recently these were the only established human cell type that could be robustly grown in the laboratory setting and still maintain full pluripotent developmental potential. In November of 2007, a new type of human pluripotent cell was created. By turning on a set of 4 genes, researchers succeeded in reprogramming human skin cells back into a cell type that appears to have very similar properties and potential as the hES cell. These new stem cells are called induced pluripotent stem (iPS) cells in order to keep the name distinct from their embryonic derived counterpart. One of the scientific limitations of hES cells is the impracticality of generating patient or disease specific stem cell lines. This opportunity now becomes theoretically practical with the advent of human iPS cell line generation. We report here on significant progress demonstrating the practicality of generating disease-linked cellular models of human diseases.
  • We have identified 2 specific human neurological diseases, Rett’s Syndrome and Schizophrenia that have a known, or strongly suggested genetic components, and have set about to generate disease-linked iPS cell lines. We have obtained skin cell samples from patients with these neurological diseases and have successfully reprogrammed them back to iPS cells. These disease-linked pluripotent stem cells have been carefully characterized and we have demonstrated that they do indeed behave very similar to existing hES cells and also to the healthy control iPS cell lines that we have generated. Therefore, the disease phenotype is not detrimental to reprogramming or proliferation as a stem cell. Furthermore, we have succeeded in coaxing these disease-linked iPS cells to turn into specific types of functional human neurons, the very cells that are suspected to be involved in the neurological disorders. We now have established a viable model for studying human neural disorders in the laboratory, and have already observed some potentially important functional differences between the disease-linked and control iPS generated neurons. Importantly, we have found defects in the function of disease-linked neurons that can be corrected in part following specific drug treatments. This discovery demonstrates the potential utility to use this method of modeling human diseases in the laboratory as a tool for understanding the detailed pathways that might contribute to the development of the disease state and importantly as a target for screening potential therapeutic compounds that might be used to block or slow the progress of human neural disorders.
  • We have also succeeded in developing an improved method for the delivery of the reprogramming genes into the patient cells in order to become iPS cells. This method combines all the of the reprogramming genes into a single cassette, and also allows the reprogramming genes to be removed thus mitigating the potential for unwanted and potentially detrimental reactivation of these reprogramming genes subsequent to the iPS cell state. We have demonstrated the success of this new reprogramming methodology to generate iPS cell lines that are specifically linked to a disease of the immune system. In addition to creating a panel of disease-linked iPS cell lines that are free of the externally introduced reprogramming transgenes, we have shown progress in achieving correction of the DNA mutation that leads to the disease state. Our extended research on these new disease specific iPS cell lines has shown utility for creating in vitro models of human neural disorders, and potential for genetically corrected patient specific iPS cell lines that could be used for cell based transplantation therapies.

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