Blocking a protein called PD-1 (programmed death 1) might provide a way to boost the function of T cells crippled by HIV, according to two studies published online in Nature and Nature Medicine.
Earlier this year, a study showed that blocking the function of PD-1 in virally infected mice could restore the function of ailing T cells and help fight infection.
In the paper published in Nature, Bruce Walker and his colleagues have now examined seventy one chronically infected HIV patients and found that their T cells have dramatically more PD-1 receptors on their surface, and that the degree of PD-1 production correlates with markers of disease progression including the extent to which T cells are disabled and the levels of virus within the body.
In the Nature Medicine study, Rafick-Pierre Sekaly and his colleagues find similar correlations in nineteen HIV infected patients and show that, over time, fluctuations in HIV load mirror levels of PD-1 expression on the T cells.
Notably, both groups of researchers find that an antibody that blocks this receptor promotes the immune response to HIV in laboratory experiments, raising hope that a similar strategy might work to fight the disease in humans.