Hopes for a stem cell cure of therapy for HIV infection were boosted in late 2010 when scientists reported that Timothy Ray Brown, also known as the Berlin Patient, had effectively had his HIV supposedly cured. Brown had received a bone marrow transplant as part of a treatment for leukaemia that came from a donor whose cells were resistant to HIV infection.
The donor of the bone marrow had a genetic mutation in a gene called CCR5, which makes a protein that is required for HIV to enter cells. The problem is that there aren’t enough people with naturally occurring CCR5 mutations to serve as bone marrow donors for all HIV patients.
The goal is to introduce a CCR5 mutation in the patient’s own blood forming stem cells then reintroduce those cells into the patient. The hope is that these cells then repopulate the immune system. Restoring a competent immune system with cells that are no longer a target for HIV is why eradication or cure becomes a possibility.
California Institute for Regenerative Medicine also provides funds to scientists at UCLA to dtudy other therapeutic strategies using stem cells to target HIV and genetic modification of the human genome to help the immune system resists HIV infection or disease progression. CIRM is providing further funds to City of Hope in order to develop other RNA-based approaches to stem cell gene therapy for HIV.
In the next few years, experts want to start testing their approach in clinical trials. Building on work that members of the CIRM have pursued over the last decade, they developed several anti-HIV genes that were inserted into blood stem cells using standard gene-therapy techniques and viral vectors.
Bone marrow transplants mark one of the earliest uses of adult stem cells. The first successful one was performed in 1968. Today, they are used to treat a host of blood and bone marrow disease, blood cancers and immune disorders. Beyond their use in bone marrow transplants, adult stem cells are used to cure or treat nearly 80 diseases.