We investigated the effects of human immunodeficiency type-1 virus (HIV-1) matrix protein p17 on freshly isolated and purified human natural killer (NK) cells. HIV-1 p17 increased the cytokines interleukin (IL) 2, IL-12 and IL-15, and induced natural killer cell proliferation, but not cytotoxicity. This effect was specific because it was abrogated by anti-p17 monoclonal antibody. Moreover, HIV-1 p17 enhanced the cytokine-induced production of tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by NK cells. IL-4 downregulated IFN-gamma and TNF-alpha secretion in IL-2- and IL-15-treated NK cells. HIV-1 p17 restored the ability of NK cells to produce both cytokines when added to the cultures simultaneously with IL-4. The property of p17 to increase the production of TNF-alpha and IFN-gamma might be a mechanism used by HIV-1 to modulate the immune system to support its replication and spreading.
HIV-1 matrix protein p17 enhances the proliferative activity of natural killercells and increases their ability to secrete proinflammatory cytokines / Vitale, Marco; Caruso, A.; DE FRANCESCO, M. A.; Rodella, L.; Bozzo, L.; Garrafa, E.; Grassi, M.; Gobbi, Giuliana; Cacchioli, Antonio; Fiorentini, S.. - In: BRITISH JOURNAL OF HAEMATOLOGY. - ISSN 0007-1048. - 120(2)(2003), pp. 337-343.