title: HIV-specific IL-10-positive CD8+ T cells suppress cytolysis and IL-2 production by CD8+ T cells.
abstract: IL-10 producing T cells inhibit Ag-specific CD8+ T cell responses and may play a role in the immune dysregulation observed in HIV infection. We have previously observed the presence of HIV-specific IL-10-positive CD8+ T cells in advanced HIV disease. In this study, we examined the suppressive function of the Gag-specific IL-10-positive CD8+ T cells. Removal of these IL-10-positive CD8+ T cells resulted in increased cytolysis and IL-2, but not IFN-gamma, production by both HIV- and human CMV-specific CD8+ T cells. In addition, these IL-10-positive CD8+ T cells mediated suppression through direct cell-cell contact, and had a distinct immunophenotypic profile compared with other regulatory T cells. We describe a new suppressor CD8+ T cell population in advanced HIV infection that may contribute to the immune dysfunction observed in HIV infection.
authors.affiliation: Viral and Ricksettial Disease Laboratory, California Department of Health Services, 850 Marina Bay Parkway, Richmond, CA 94804, USA. melrefae@dhs.ca.gov
authors.forename: Mohamed
authors.initials: M
authors.lastname: Elrefaei
authors.forename: Florence L
authors.initials: FL
authors.lastname: Ventura
authors.forename: Chris A R
authors.initials: CA
authors.lastname: Baker
authors.forename: Richard
authors.initials: R
authors.lastname: Clark
authors.forename: David R
authors.initials: DR
authors.lastname: Bangsberg
authors.forename: Huyen
authors.initials: H
authors.lastname: Cao
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005260:Female; D015683:Gene Products, gag / Q000276:immunology; D006679:HIV Seropositivity / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology*; D007376:Interleukin-2 / Q000276:immunology*; D008297:Male
chemical_list: D015683:Gene Products, gag; D007376:Interleukin-2; D016753:Interleukin-10; D007371:Interferon-gamma