Two research groups of scientists have announced that they know why the immune system is unable to control the HIV virus and how the system may be manipulated to fight various diseases, including cancer, according to CBS News. Healthy individuals generate T-cells, which attack viruses. However, in people affected by HIV, those cells cease to work properly. Although one hypothesis stipulates that the T-cells are destroyed, Dr. Bruce Walker, M.D., of Massachusetts General Hospital, is among those who have discovered that the cells are actually present—they just have been turned off. 'A major puzzle has been that even in late-stage illness, when one can still measure great numbers of these immune cells, they don't seem to be controlling the virus at all,' he said in an item printed in MedPage Today. The result raises the possibility that physicians could switch a chronically ill patient's immune system back on to continue its fight against HIV, cancer or even hepatitis C.
However, doctors are concerned that the switch could actually start an autoimmune disease that would attack healthy parts of the body. Walker, whose research findings appeared online in Nature, led one of the teams reporting that an inhibitory molecule called programmed death-1 ( PD-1 ) is overexpressed on HIV-specific CD8 T-cells in people with high viral loads. Rafick-Pierre Sékaly, Ph.D., of the University of Montreal, helmed the other team, whose findings were published online in Nature Medicine.