title: Enhancement of NK cell-mediated antibody-dependent lysis of recombinant gp120-coated CD4 cells by complement.
abstract: The contribution of complement to NK cell lysis of CD4 cells expressing recombinant gp120 (rgp120) was investigated. Peripheral blood mononuclear cells were used as effector cells in a Cr release assay against purified CD4 target cells that had been coated with rgp120. Assays included human immunodeficiency virus (HIV) antibodies and a complement source alone and in combination to determine their importance in mediating cytotoxicity. NK cells were confirmed to be the effector cells in the lysis of rgp120-coated CD4 targets. Anti-HIV was crucial for lysis and cytotoxicity was enhanced by C3 deposition on targets. However, a prozone effect was observed, with reduced IgG binding, C3 deposition, and NK cell lysis at serum concentrations > 10 micrograms IgG/mL. The susceptibility of these CD4-gp120-antibody-C3 complexes to NK cell lysis may contribute to progressive depletion of CD4 cells in HIV infection.
authors.affiliation: Department of Microbiology and Infectious Diseases, Flinders Medical Centre, South Australia, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Parker
authors.forename: T A
authors.initials: TA
authors.lastname: Sadlon
authors.forename: D L
authors.initials: DL
authors.lastname: Gordon
mesh_terms: D000920:Antibody-Dependent Cell Cytotoxicity; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D003176:Complement C3 / Q000276:immunology; D003165:Complement System Proteins / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D003176:Complement C3; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D003165:Complement System Proteins