title: In vivo induction of cellular and humoral immune responses by hybrid DNA vectors encoding simian/human immunodeficiency virus/hepatitis B surface antigen virus particles in BALB/c and HLA-A2-transgenic mice.
abstract: To improve the immunogenicity of epitopes derived from Gag proteins of simian immunodeficiency virus (SIV) and from the envelope (Env) protein of human immunodeficiency virus type 1 (HIV-1), we have designed hybrid DNA vaccines by inserting sequences encoding antigenic domains of SIV and HIV-1 into the hepatitis B virus envelope gene. This gene encodes the hepatitis B surface antigen (HBsAg) capable of spontaneous assembly into virus-like particles that were used here as carrier. Injections of hybrid vectors encoding B-cell epitopes from the gp41 and the gp120 envelope proteins of HIV-1 induced specific humoral responses in BALB/c mice. Furthermore, high frequencies of IFN-gamma-secreting CD8+ T cells specific for various antigenic determinants of SIV-Gag were observed after intramuscular injections of hybrid DNA vectors in BALB/c mice. Genetic immunization of HLA-A2.1-transgenic mice with HIV-Env/HBsAg-encoding DNA generated a strong CTL response and IFN-gamma-secreting CD8+ T lymphocytes specific for HIV-1 envelope-derived peptide. H-2d-restricted HBs-specific T-cell responses dominated over SIV-Gag responses in BALB/c mice whereas HLA-A2-restricted HIV-Env response was enhanced after fusion with HBsAg. These data demonstrate that different B and T-cell epitopes of vaccine-relevant viral antigens can be expressed in vivo as fusion proteins with HBsAg but that the optimal immunogenicity may differ strikingly between individual epitopes.
authors.affiliation: INSERM U 370 Carcinogenèse Hépatique et Virologie Moléculaire, Département de Médecine Moléculaire, Institut Pasteur, 28, rue du Docteur Roux, 75724 PARIS CEDEX 15, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Marsac
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Puaux
authors.forename: Yves
authors.initials: Y
authors.lastname: Rivière
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Michel
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002460:Cell Line; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D015683:Gene Products, gag / Q000276:immunology; D015488:HIV Antigens / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000235:genetics; D006509:Hepatitis B / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D015302:Simian Immunodeficiency Virus / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins / Q000276:immunology; D014771:Virion / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; D015683:Gene Products, gag; D015488:HIV Antigens; D015789:HLA-A2 Antigen; D006514:Hepatitis B Surface Antigens; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D007371:Interferon-gamma