CHICAGO - US scientists have discovered the basic mechanisms that allow HIV to wipe out the body's immune system and cause AIDS, which could lead to new approaches to treatment and research for a cure for the disease that affects 35 million people around the world.
Instead of actively killing immune system cells known as CD4 T cells, much of the damage done by HIV occurs when the virus tries to invade these cells and fails, triggering an innate immune response that causes the cells to self-destruct in a fiery kind of cell suicide known as pyroptosis.
The findings, published simultaneously in the scientific journals Science and Nature, also suggest that an experimental anti-inflammatory drug owned by Vertex Pharmaceuticals Inc that has already been tested in people with epilepsy could be repurposed as a possible new treatment for AIDS.
"Our papers deal with the fundamental issue that causes AIDS, and that is the loss of CD4 T cells," said Dr Warner Greene of the Gladstone Institutes, an independent biomedical research nonprofit based in San Francisco, whose lab produced the research in both papers.
Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, said the papers offer an "elegant" solution to a question that has eluded scientists since the virus was first identified in 1983.
Greene said for years, scientists had thought that HIV killed immune system cells by infecting them directly, hijacking their DNA machinery and turning them into virus-producing factories.
But this only happens to a small portion of CD4 T cells. In a series of experiments in human spleen, tonsil and lymph node tissues from HIV-infected patients, the Gladstone scientists discovered that the real damage of HIV infection occurs in so-called "bystander cells," the most common type of CD4 T cell.