title: Enhanced activation of human T cell clones specific for virus-like particles expressing the HIV V3 loop in the presence of HIV V3 loop-specific polyclonal antibodies.
abstract: Recombinant virus-like particles (VLP), formed by the yeast Ty p1 protein, carrying the HIV gp120 V3 loop on their surface (V3-VLP) have been tested in vitro for immunogenicity and antigenicity by using VLP p1-specific human CD4+ T cell lines and clones. VLP-specific human T cell lines and clones were generated from normal individuals, indicating that VLP-specific precursor cells present in the peripheral lymphocyte pool can be induced to expand clonally upon antigen challenge in vitro, in the absence of previous immunization. It was also shown that V3-specific polyclonal antibodies enhance V3-VLP-induced activation of VLP-specific T cell clones. Antibody-dependent potentiation has been shown previously in other antigen systems, and it depends on enhanced uptake of complexed antigen by Fc receptor-positive antigen-presenting cells. Since in this case antigen is internalized by presenting cells as a complex, it can be inferred that a similar event of antibody-mediated antigen uptake can take place with V3-specific B cells, resulting in presentation by the B cells of T helper epitopes derived from processing of the VLP p1 moiety. This suggests that T helper cells specific for the carrier VLP p1 protein can be activated to provide help to V3-specific B cells in the presence of the appropriate antigen construct.
authors.affiliation: Department of Immunology, San Martino Hospital, University of Genoa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Peifang
authors.forename: G L
authors.initials: GL
authors.lastname: Pira
authors.forename: D
authors.initials: D
authors.lastname: Fenoglio
authors.forename: S
authors.initials: S
authors.lastname: Harris
authors.forename: M G
authors.initials: MG
authors.lastname: Costa
authors.forename: V
authors.initials: V
authors.lastname: Venturino
authors.forename: V
authors.initials: V
authors.lastname: Dessì
authors.forename: G
authors.initials: G
authors.lastname: Layton
authors.forename: J
authors.initials: J
authors.lastname: Laman
authors.forename: J G
authors.initials: JG
authors.lastname: Huisman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D016367:Baculoviridae / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D002999:Clone Cells; D015483:HIV Antibodies / Q000276:immunology*; D015488:HIV Antigens / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000276:immunology
chemical_list: D015483:HIV Antibodies; D015488:HIV Antigens; D015699:HIV Envelope Protein gp120; D010455:Peptides; D011993:Recombinant Fusion Proteins