Function of NKT cells, potential anti-HIV effector cells, are improved by beginning HAART during acute HIV-1 infection.

NKT cells are a subset of lymphocytes that share features of T cells and NK cells and bridge the innate and adaptive immune responses. They are able to be infected by HIV, but their function in HIV-infected individuals is not known. NKT cell percentage and function was measured in individuals with acute HIV infection before and 1 year into highly active anti-retroviral therapy (HAART). This study demonstrates that percentages of both CD161+ NKT cells and CD161+, CD4+ NKT cells decline within the first few months after HIV-1 infection, but initiating therapy during the acute infection period can prevent a further decline in these NKT cell subsets during the first year. NKT cell function is also impaired during early HIV infection, but significantly improved by effective treatment with HAART. Finally, preservation of NKT cell function may be important in HIV-infected individuals, as NKT cells display an anti-HIV-1 activity in vitro, mediated by IFN-gamma secretion.