title: An influenza haemagglutinin-specific IgG enhances class I MHC-restricted CTL killing in vitro.
abstract: Lungs of H-2k mice co-inoculated with type A/WSN influenza virus+detective interfering WSN virus contain haemagglutinin (HA)-specific IgG which have three different activities. These have been purified by adsorbtion and elution using different forms of HA. The first IgG recognizes HA in a form present on H-2k cells infected with a vaccinia virus recombinant expressing the WSN HA gene (vaccinia-HA virus), but not on virus particles, and enhances class I major histocompatibility complex (MHC)-restricted killing of WSN-infected H-2k target cells by primary cytotoxic T lymphocytes (CTL) from the lungs of WSN-infected H-2k mice; it also confers on primary CTL from the lungs of WSN-infected H-2d mice the ability to lyse WSN-infected H-2k targets. This IgG is therefore analogous to the T-cell receptor in that it is antigen specific and MHC restricted. A second IgG recognizes HA in a form present on both H-2k and H-2d cells infected with the vaccinia-HA virus but not present on virus particles and inhibits CTL lysis of WSN-infected syngeneic target cells. Only the third binds to virus particles; this inhibits agglutination of red cells, but is non-neutralizing. It also inhibits CTL lysis of WSN-infected syngeneic targets. Thus we present evidence that HA-specific IgG may have a significant role in regulating CTL responses to influenza virus in vivo and that one of these IgG is MHC-restricted in its recognition of viral antigen. Finally, in vivo significance of these antibodies is indicated by the finding that adoptively transferred CTL-enhancing IgG protects mice from lethal WSN infection.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry, U.K.
authors.forename: L
authors.initials: L
authors.lastname: McLain
authors.forename: N J
authors.initials: NJ
authors.lastname: Dimmock
mesh_terms: D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology* / Q000627:therapeutic use; D009980:Influenza A virus / Q000276:immunology; D008168:Lung / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D009976:Orthomyxoviridae Infections / Q000517:prevention & control
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D015395:Histocompatibility Antigens Class I; D007074:Immunoglobulin G