title: Immune response to a potyvirus with exposed amino groups available for chemical conjugation.
abstract: BACKGROUND
  The amino terminus of the tobacco etch virus (TEV) capsid protein is located on the external surface of infectious TEV particles, as proposed by previous studies and an in silico model. The epsilon amino groups on the exposed lysine residues are available for chemical conjugation to any given protein, and can thus act as antigen carriers. The availability of amino groups on the surfaces of TEV particles was determined and the immune response to TEV evaluated.
  
  
  RESULTS
  Using a biotin-tagged molecule that reacts specifically with amino groups, we found that the TEV capsid protein has amino groups on its surface available for coupling to other molecules via crosslinkers. Intraperitoneal TEV was administered to female BALB/c mice, and both their humoral and cellular responses measured. Different IgG isotypes, particularly IgG2a, directed against TEV were induced. In a cell proliferation assay, only spleen cells from vaccinated mice that were stimulated in vitro with TEV showed significant proliferation of CD3+/CD4+ and CD3+/CD8+ subpopulations and secreted significant amounts of interferon γ.
  
  
  CONCLUSIONS
  TEV has surface amino groups that are available for chemical coupling. TEV induces both humoral and cellular responses when administered alone intraperitoneally to mice. Therefore, TEV should be evaluated as a vaccine adjuvant when chemically coupled to antigens of choice.
authors.affiliation: Unidad de Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Normalistas 800, Colinas de la Normal, Guadalajara, Jalisco 44270, México.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Manuel-Cabrera
authors.forename: Ana
authors.initials: A
authors.lastname: Márquez-Aguirre
authors.forename: Hernández-Gutiérrez
authors.initials: HG
authors.lastname: Rodolfo
authors.forename: Pablo César
authors.initials: PC
authors.lastname: Ortiz-Lazareno
authors.forename: Gabriela
authors.initials: G
authors.lastname: Chavez-Calvillo
authors.forename: Mauricio
authors.initials: M
authors.lastname: Carrillo-Tripp
authors.forename: Laura
authors.initials: L
authors.lastname: Silva-Rosales
authors.forename: Abel
authors.initials: A
authors.lastname: Gutiérrez-Ortega
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology; D036022:Capsid Proteins / Q000737:chemistry* / Q000276:immunology; D004337:Drug Carriers; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D017800:Potyvirus / Q000737:chemistry / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000737:chemistry / Q000276:immunology; D014765:Viral Vaccines / Q000737:chemistry / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D017252:CD3 Complex; D036022:Capsid Proteins; D004337:Drug Carriers; D007074:Immunoglobulin G; D018074:Vaccines, Conjugate; D014765:Viral Vaccines; D007371:Interferon-gamma