Mass cytometry identifies distinct CD4+ T cell clusters distinguishing HIV-1-infected patients according to antiretroviral therapy initiation.

Recent guidelines recommend antiretroviral therapy (ART) to be administered as early as possible during HIV-1 infection. Few studies addressed the immunological benefit of commencing ART during the acute phase of infection. We used mass cytometry to characterize blood CD4+ T cells from HIV-1-infected patients who initiated ART during acute or chronic phase of infection. Using this method, we analyzed a large number of markers on millions of individual immune cells. The results revealed that CD4+ T cell clusters with high expression of CD27, CD28, CD127, and CD44, whose function involves T cell migration to inflamed tissues and survival, are more abundant in healthy controls and patients initiating ART during the acute phase; on the contrary, CD4+ T cell clusters in patients initiating ART during the chronic phase had reduced expression of these markers. The results are suggestive of a better preserved immune function in HIV-1-infected patients initiating ART during acute infection.