title: Strong ability of Nef-specific CD4+ cytotoxic T cells to suppress human immunodeficiency virus type 1 (HIV-1) replication in HIV-1-infected CD4+ T cells and macrophages.
abstract: A restricted number of studies have shown that human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic CD4+ T cells are present in HIV-1-infected individuals. However, the roles of this type of CD4+ T cell in the immune responses against an HIV-1 infection remain unclear. In this study, we identified novel Nef epitope-specific HLA-DRB1*0803-restricted cytotoxic CD4+ T cells. The CD4+ T-cell clones specific for Nef187-203 showed strong gamma interferon production after having been stimulated with autologous B-lymphoblastoid cells infected with recombinant vaccinia virus expressing Nef or pulsed with heat-inactivated virus particles, indicating the presentation of the epitope antigen through both exogenous and endogenous major histocompatibility complex class II processing pathways. Nef187-203-specific CD4+ T-cell clones exhibited strong cytotoxic activity against both HIV-1-infected macrophages and CD4+ T cells from an HLA-DRB1*0803+ donor. In addition, these Nef-specific cytotoxic CD4+ T-cell clones exhibited strong ability to suppress HIV-1 replication in both macrophages and CD4+ T cells in vitro. Nef187-203-specific cytotoxic CD4+ T cells were detected in cultures of peptide-stimulated peripheral blood mononuclear cells (PBMCs) and in ex vivo PBMCs from 40% and 20% of DRB1*0803+ donors, respectively. These results suggest that HIV-1-specific CD4+ T cells may directly control HIV-1 infection in vivo by suppressing virus replication in HIV-1 natural host cells.
authors.affiliation: Division of Viral Immunology, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
authors.forename: Nan
authors.initials: N
authors.lastname: Zheng
authors.forename: Mamoru
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Takamasa
authors.initials: T
authors.lastname: Ueno
authors.forename: Shinichi
authors.initials: S
authors.lastname: Oka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takiguchi
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D002478:Cells, Cultured; D015536:Down-Regulation; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000821:virology; D008264:Macrophages / Q000276:immunology / Q000821:virology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000821:virology; D014779:Virus Replication / Q000187:drug effects; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000276:immunology* / Q000627:therapeutic use
chemical_list: D054311:nef Gene Products, Human Immunodeficiency Virus