CD73+ CD127high long-term memory CD4 T cells are highly proliferative in response to recall antigens and are early targets in HIV-1 infection

HIV-1 infection rapidly leads to a loss of the proliferative response of memory CD4+ T lymphocytes, when cultured with recall antigens. We report here that CD73 expression defines a subset of resting memory CD4 T cells which highly express the alpha-chain of the receptor for IL-7 (CD127), but not CD38 or Ki-67 in vivo, yet are highly proliferative in response to mitogen and recall antigens, and to IL-7, in vitro. These cells also preferentially express CCR5 and produce IL-2. We reasoned that CD73+ memory CD4+ T cells decrease early in HIV-1 infection. We compared gene expression profiles of healthy subjects recovered CD4+CD73+ to CD4+CD73- T cells, and also CD8+CD73+ to CD8+CD73- T cells Lymphocytes were recovered from healthy subjects. T lymphocytes CD4+CD73+ were compared to CD4+CD73- and CD8+CD73+ were compared to CD8+CD73-