Cutting edge: HIV-1 infection induces a selective reduction in STAT5 protein expression

HIV-1 infection is accompanied by qualitative and quantitative defects in CD4⁺ T lymphocytes. Loss of immune function in HIV patients is usually associated with a profound dyregulation of cytokine production. To investigate whether cytokine signaling defects occur during HIV infection, PHA blasts from healthy human donors were infected with two strains of HIV-1 and screened for the expression of STAT proteins used in cytokine signaling. A selective decrease in STAT5B was seen 8 days after infection with the BZ167 dual tropic HIV isolate, but not with the Ba-L, M-tropic strain. Based on these findns, purified T cells from HIV-infected patients in different stages of disease were also tested for STAT expression; deceases in STAT5A, STAT5B- and STAT1α were obsevd in all paients. The reducton in STATs seen in vivo and in vitro after HIV infection may contribute to the loss of T cell function in HIV disease.