HIV "Elite Controllers" are characterized by a high frequency of memory CD8CD73 T cells involved in the antigen-specific CD8 T-cell response

Human immunodeficiency virus type 1 (HIV-1) infection is characterized by chronic immune activation and suppressed T-lymphocyte functions. Here we report that CD73, both a coactivator molecule of T cells and an immunosuppressive ecto-enzyme through adenosine production, is only weakly expressed by CD8 T cells of HIV-infected patients and only partially restored after successful antiviral treatment. CD73 expression on CD8 T cells correlates inversely with cell activation both ex vivo and in vitro. However, CD8 T cells from HIV controllers (HICs), which spontaneously control HIV replication, express CD73 strongly, despite residual immune activation. Finally, we demonstrate that CD73 is involved in the HIV-specific CD8 T-cell expansion. Thus, we show that CD73 is central to the functionality of HIV-specific CD8 T cells and that the preservation of HIV-specific CD73CD8 T cells is a characteristic of HICs. These observations reveal a novel mechanism involved in the control of viral replication. © The Author 2013.