title: Induction of cytolytic T lymphocytes directed towards the V3 loop of the human immunodeficiency virus type 1 external glycoprotein gp120 by p55gag/V3 chimeric vaccinia viruses.
abstract: T cell-mediated cytotoxicity may play an important role in controlling infection by human immunodeficiency virus (HIV). In order to study the ability of rationally designed antigens to induce cytolytic T lymphocytes (CTLs) we replaced stretches of 30 to 50 amino acids at the p17-MA/p24-CA cleavage site, within the p24-CA moiety and within the p6-LI portion of the HIV type 1 p55gag precursor by the third variable domain (V3) of the external glycoprotein gp120. This site is known to be a target for CTL attack in mice and humans. The chimeric antigens were recombined into highly attenuated vaccinia viruses in order to investigate class I major histocompatibility complex (MHC)-restricted presentation of antigenic V3 peptides. Immunoprecipitation and Western blot analysis of the group-specific antigen (p55gag)/V3 chimeric proteins demonstrated significant differences in the accessibility of the V3 domain for a monoclonal antibody or polyclonal V3-specific antisera, depending on the position of the V3 loop within the p55gag carrier protein. Immunization of BALB/c mice with three variants of p55gag/V3 recombinant vaccinia virus, however, resulted in a comparable priming of CD4-CD8+ CTLs in vivo irrelevant of the position of the V3 loop within p55gag. Local conformational changes, including the V3 domain within the p55gag/V3 chimeras, did not demonstrate a significant effect on V3-specific lysis of the target cells when compared to the authentic gp120 envelope protein. Class I MHC-restricted CTLs induced by a V3 consensus sequence cross-reacted perfectly with the LAI strain-derived V3 loop sequence. These data indicate that the combination of selected epitopes (V3) with immunologically relevant complex carrier proteins (p55gag) can be accomplished without the loss of biological activity.
authors.affiliation: Institute for Medical Microbiology, University of Regensburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Wagner
authors.forename: T
authors.initials: T
authors.lastname: Böltz
authors.forename: L
authors.initials: L
authors.lastname: Deml
authors.forename: S
authors.initials: S
authors.lastname: Modrow
authors.forename: H
authors.initials: H
authors.lastname: Wolf
mesh_terms: D016915:AIDS Vaccines / Q000096:biosynthesis* / Q000276:immunology / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D015683:Gene Products, gag / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D015750:Genes, gag; D015699:HIV Envelope Protein gp120 / Q000276:immunology* / Q000302:isolation & purification; D015497:HIV-1 / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins / Q000276:immunology* / Q000302:isolation & purification; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014616:Vaccinia virus / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D016915:AIDS Vaccines; D000911:Antibodies, Monoclonal; D000939:Epitopes; D015683:Gene Products, gag; D015699:HIV Envelope Protein gp120; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins