title: Increased IFN-gamma production by NK and CD3+/CD56+ cells in sexually HIV-1-exposed but uninfected individuals.
abstract: The mechanisms involved in controlling the establishment of HIV-1 infection are not fully understood. In particular, the role of innate immunity in natural resistance exhibited by individuals who are continuously exposed to HIV-1 but remain seronegative (ESN) has not been thoroughly evaluated. We determined the frequency and function of peripheral blood innate immune cells (plasmacytoid and myeloid dendritic cells, monocytes, NK cells, CD3+/CD56+ cells and invariant NKT cells) in ESN, chronically HIV-1-infected and low-risk HIV-1 seronegative individuals. ESN demonstrated a similar frequency of innate immune cells in comparison to controls and a higher frequency of dendritic cells, NK and invariant NKT cells compared to HIV-1-infected subjects. Incubation of mononuclear cells with stimulatory CpG ODN induced CD86 and CD69 up-regulation to a similar degree on innate cells from the three study groups. CpG ODN-stimulated secretion of cytokines was also similar between ESN and controls, while secretion of IFN-alpha was significantly decreased in HIV-1+ individuals. Importantly, expression of IFN-gamma by PMA/Ionomycin-activated CD56(bright) NK cells and CD3+/CD56+ cells was significantly higher in ESN when compared with controls. The anti-viral effects of IFN-gamma are well established, and so our results suggest that IFN-gamma production by innate immune cells might be one of the multiple factors involved in controlling the establishment of sexually transmitted HIV-1 infection.
authors.affiliation: Group of Immunovirology, Biogenesis Corporation, University of Antioquia, Medellin, Colombia. cmontoya@virologia.udea.edu.co
authors.forename: Carlos Julio
authors.initials: CJ
authors.lastname: Montoya
authors.forename: Paula Andrea
authors.initials: PA
authors.lastname: Velilla
authors.forename: Claire
authors.initials: C
authors.lastname: Chougnet
authors.forename: Alan L
authors.initials: AL
authors.lastname: Landay
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rugeles
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000097:blood; D000945:Antigens, Differentiation, T-Lymphocyte / Q000097:blood; D051940:B7-2 Antigen / Q000097:blood; D017252:CD3 Complex / Q000096:biosynthesis*; D019002:CD56 Antigen / Q000096:biosynthesis*; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D018023:HIV Seronegativity / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007109:Immunity; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis*; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008297:Male; D008875:Middle Aged; D015854:Up-Regulation; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D051940:B7-2 Antigen; D017252:CD3 Complex; D019002:CD56 Antigen; D007371:Interferon-gamma; D037181:Lectins, C-Type; D000099192:CD69 Antigens