The February 15 issue of the medical journal, ‘Nature Medicine,’ carries the full report of a clinical trial on a gene therapy for treating human immunodeficiency virus (HIV).  The therapy has proven so promising it is being hailed as a ‘major advance’ in the fight against this devastating disease.

Researchers at the University of California, Los Angeles (UCLA), led by Ronald T. Mitsuyasu, introduced an anti-HIV gene into the bone marrow of 38 HIV patients and monitored their medical status for 100 weeks after treatment. A second group of 36 HIV patients were infused with inactive (placebo) cells and served as the control group for the study.  Every study participant, regardless of which group he or she was assigned, had their HIV infection under control at the outset of the study by using highly active antiretroviral (HAART) drug therapies.

Some of the highlights of the research include:

• Patients getting the treated cells had higher T-cell counts than the control group, indicating a strengthened immune system.
• When patients receiving the active genes stopped taking anti-HIV medications, they were able to enjoy a drug-free period that lasted longer than those who got the placebo cells.
• When drugs were stopped, those patients treated with the active genes had higher T-cell counts and a lower viral load than those getting the placebo.
• No one was harmed by the therapy or by participation in the study.

In the UCLA study, participants were first given a human growth factor to stimulate production of virus-fighting white blood cells (T cells).  These white blood cells were then removed from the blood and stem cells were isolated.

Once isolated, the stem cells in the active group were infected with OZ1, which is a mouse virus genetically engineered to produce an anti-HIV gene.  This gene targets HIV genes, which it renders inactive.

After HIV-resistant T cells developed, they were placed back into the patient’s body, where they reproduced in the bone marrow, populating it with HIV-resistant T cells.  As the HIV infection killed untreated T cells or they died off naturally, they were replaced by the new, HIV-resistant T cells.

The therapy is a one-time event that involves some complicated steps but the results thus far have been so promising that further studies are anticipated.  Some areas under consideration for future study include increasing the dose of OZ1-treated cells, improving the way the treated cells home in on the bone marrow, using an even more powerful anti-HIV gene, and starting gene therapy before anti-HIV drugs are prescribed.