Stories of Hope: HIV/AIDS
We have come a long way in our ability to help people infected with HIV, the virus that causes AIDS. Antiretroviral therapy, using a combination of HIV medicines, means the disease can now often be managed as a chronic condition. But many researchers are still working on developing a cure, so that people no longer need to take medications to control their HIV.
CIRM has funded four different clinical trials targeting HIV. These use a similar approach, taking the patient’s own blood forming stem cells and genetically “editing” them to either block the ability of HIV to infect cells, or boost the patient’s own immune system to fight back against the virus.
Dr. John Zaia and a team at City of Hope and Sangamo Therapeutics is genetically modifying patients' blood forming stem cells to functionally cure people with HIV. The team is using a technology called zinc finger nucleases – a kind of molecular scissors – to snip out the target gene that codes for the CCR5 receptor. This receptor is the gateway for the HIV virus into immune cells. The hope is that this treatment will provide a renewable, long-lasting source of HIV resistant immune cells in patients.
Dr. Steve Deeks and a team at the University of California San Francisco (UCSF) is conducting a clinical trial that modifies a patient’s own immune cells in order to treat and potentially cure HIV. The team will take a patient’s blood and extract T cells, a type of immune cell. The T cells are then genetically modified to express two different chimeric antigen receptors (CAR), which enable the newly created duoCAR-T cells to recognize and destroy HIV infected cells. The modified T cells are then reintroduced back into the patient. The goal of this one-time therapy is to act as a long-term control of HIV with patients no longer needing to take ART, in effect a form of HIV cure. This approach would also address the needs of those who are not able to respond to current approaches, which is estimated to be 50% of those affected by HIV globally.
A team at UC Davis, led by Dr. Mehrdad Abedi, is taking a patient’s blood forming stem cells and inserting three anti-HIV genes into them and then returning them to the individual to help rebuild their immune system. The anti-HIV genes are then passed on to all new immune system cells, which makes them resistant to HIV. Because AIDS-related lymphoma is linked to the constant immune cell stimulation caused by HIV infection, getting rid of the virus should prevent return of the cancer.