title: Antibody-dependent cellular cytotoxicity via humoral immune epitope of Nef protein expressed on cell surface.
abstract: Antibodies against various proteins of HIV type 1 (HIV-1) can be detected in HIV-1-infected individuals. We previously reported that the level of Ab response against one Nef epitope is correlated with HIV-1 disease progression. To elucidate the mechanism for this correlation, we examined Ab-dependent cellular cytotoxicity (ADCC) against target cells expressing Nef. We observed efficient cytotoxicity against Nef-expressing target cells in the presence of patient plasma and PBMCs. This ADCC activity was correlated with the dilution of plasma from HIV-1-infected patients. Addition of a specific synthetic peptide (peptide 31:FLKEKGGLE) corresponding to the Nef epitope reduced cell lysis to approximately 50%. These results suggest that PBMCs of HIV-1-infected patients may exert ADCC via anti-Nef Abs in the patients' own plasma and serve as a mechanism used by the immune system to regulate HIV-1 replication.
authors.affiliation: Department of Infectious Disease and Applied Immunology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamada
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Watanabe
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Aikichi
authors.initials: A
authors.lastname: Iwamoto
mesh_terms: D000328:Adult; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism / Q000821:virology; D003601:Cytotoxicity Tests, Immunologic; D018450:Disease Progression; D015693:Gene Products, nef / Q000096:biosynthesis / Q000276:immunology*; D015483:HIV Antibodies / Q000096:biosynthesis*; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016056:Immunodominant Epitopes / Q000096:biosynthesis / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism* / Q000821:virology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology; D029082:Sendai virus / Q000276:immunology; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015693:Gene Products, nef; D015483:HIV Antibodies; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D054311:nef Gene Products, Human Immunodeficiency Virus