Elite controllers' T cells resist HIV-1 infection by selective upregulation of protein p21

In the years since the AIDS epidemic began, it has become clear that there is substantial variation in the way that individuals respond to HIV infection. Although most progress quickly from initial infection to immunodeficiency, a small subset survive for long periods without developing symptoms. These patients, dubbed elite controllers, display undetectable levels of viral replication, but the mechanism that explains how their immune systems effectively control the virus is not understood.

In this paper, Mathias Lichterfeld and colleagues, at Massachusetts General Hospital in Boston, describe that the T cells from elite controllers are relatively resistant to infection with HIV because they upregulate a protein called p21, which in turn inhibits an enzyme required for the virus to replicate. In addition, blocking p21 increased the expression of viral genes. The researchers hope that this finding may inform the design and development of treatment strategies for patients who are more susceptible to the virus' tragic effects