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 dysregulation 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 findings, purified T cells from HIV-infected patients in different stages of disease were also tested for STAT expression; decreases in STAT5A, STAT5B, and STAT1 alpha were observed in all patients, The reduction in STATs seen in vivo and in vitro after HIV infection may contribute to the loss of T cell function in HIV disease.