Objective: To determine the functions of in vitro primed Natural Killer (NM) cells in Human Immunodeficiency Virus (HIV-1) infection and the role of IL-2, IL-12 and IL-15 in enhancing the NM survival and activity in terms of viral suppression and of purging of HIV provirus. Methods: Peripheral Blood Mononuclear Cells (PBMCs) and CD4+ T lymphocytes cells obtained from eight healthy donors were infected in vitro with HIV-1 and p24 was measured with and without IL-2, IL-12 and IL-15. We studied the effect of NM pulsed in vitro with IL-2, IL-12 and IL-15 on HIV replication by measurement of p-24 and DNA-provirus load when added into the culture of PBMCs and CD4+ T lymphocytes cells infected in vitro. We evaluated the effect of NK cells pulsed with IL-2, IL-12 and IL-15 on HIV replication and DNA-load into the culture of CD4+ T lymphocytes cells and PBMCs by trans-well chamber. Results: We found high levels of p24 in the supernatants of PBMCs and CD4+ T lymphocytes cells cultured with IL-2, IL-12, and IL-15. We observed a significant reduction of p24 in the culture both of infected PBMCs and CD4+ T lymphocytes cells in which was added NK pulsed with IL-15. We did not obtain the some results with NM pulsed with IL-2 and IL-12. We observed a power effect of NK pulsed with IL-15 on HIV-DNA. The trans-well chamber experiments showed that the effect of NM is both direct and both mediated by realizing of soluble factors. Conclusions: This study highlights some important effects of IL 15 on NK in HIV patients anyway our results are preliminary and descriptive and others studies will be needed to provide rationale for immune therapies. (C) 2011 Elsevier Ltd. All rights reserved.