title: DNA vaccine encoding human immunodeficiency virus-1 Gag, targeted to the major histocompatibility complex II compartment by lysosomal-associated membrane protein, elicits enhanced long-term memory response.
abstract: Antigen presentation by major histocompatibility complex type II (MHC II) molecules and activation of CD4+ helper T cells are critical for the generation of immunological memory. We previously described a DNA vaccine encoding human immunodeficiency virus-1 p55Gag as a chimera with the lysosome-associated membrane protein (LAMP/gag). The LAMP/gag chimera protein traffics to the MHC II compartment of transfected cells and elicits enhanced immune responses as compared to a DNA vaccine encoding native gag not targeted to the MHC II compartment. We have now investigated the long-term responses of immunized mice and show that the LAMP/gag DNA vaccine promotes long-lasting B cell- and CD4+ and CD8+ T-cell memory responses induced by DNA encoding non-targeted Gag decay rapidly and elicit very low or undetectable levels of gag DNA is sufficient to generate T-cell memory. Following this initial priming immunization with LAMP/gag DNA, booster immunizations with native gag DNA or the LAMP/gag chimera are equally efficient in eliciting B- and T-cell secondary responses, results in accordance with observations that secondary expansion of CD8+ cells in the boost phase does not require additional CD4+ help. These findings underscore the significance of targeting DNA-encoded vaccine antigens to the MHC II processing compartments for induction of long-term immunological memory.
authors.affiliation: Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Luciana Barros
authors.initials: LB
authors.lastname: de Arruda
authors.forename: Priya R
authors.initials: PR
authors.lastname: Chikhlikar
authors.forename: J Thomas
authors.initials: JT
authors.lastname: August
authors.forename: Ernesto T A
authors.initials: ET
authors.lastname: Marques
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D015483:HIV Antibodies / Q000096:biosynthesis; D015497:HIV-1 / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000276:immunology; D051907:Lysosomal Membrane Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D015703:Antigens, CD; D015683:Gene Products, gag; D015483:HIV Antibodies; D000949:Histocompatibility Antigens Class II; D051907:Lysosomal Membrane Proteins; D019444:Vaccines, DNA