title: Immunogenicity of Mycobacterium bovis BCG expressing Anaplasma marginale MSP1a antigen.
abstract: Humoral and cellular immune responses of mice inoculated with recombinant Mycobacterium bovis BCG expressing the MSP1a antigen of Anaplasma marginale were evaluated. The msp1a gene was amplified by PCR and cloned into the mycobacterial expression vectors pUS2000 and pMIP12. Immunization of isogenic BALB/c mice with the rBCG/pUS2000-msp1a construct induced significant seroconversion to MSP1a (p<0.001), which was 26 times above pre-immunization levels at day 63 post-initial immunization and which remained stable for the duration of the experiment (6 months). In contrast, rBCG/pMIP12-msp1a induced seroconversion at a level of 6 times above pre-immunization values, which peaked at day 63. Western blot analysis showed that sera derived from mice vaccinated with either rBCG construct recognized both native and recombinant forms of A. marginale MSP1a. In contrast to the humoral response data, immunization with rBCG/pMIP12-msp1a was found to induce a markedly stronger cellular response than that recorded for BCG/pUS2000-msp1a. These observations clearly demonstrated the immunogenicity of recombinant BCG expressing the MSP1a antigen and suggested that the immune responses were influenced by the level of antigen expression. The results of this research warrant studies of recombinant M. bovis BCG expressing MSP1a in cattle to test for protective antibody production for control of bovine anaplasmosis.
authors.affiliation: Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, 96010-900 Pelotas, RS, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Michelon
authors.forename: Fabricio Rochedo
authors.initials: FR
authors.lastname: Conceição
authors.forename: Pedro Canisio
authors.initials: PC
authors.lastname: Binsfeld
authors.forename: Cristina Wetzel
authors.initials: CW
authors.lastname: da Cunha
authors.forename: Angela Nunes
authors.initials: AN
authors.lastname: Moreira
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Argondizzo
authors.forename: Douglas
authors.initials: D
authors.lastname: McIntosh
authors.forename: Geraldo R G
authors.initials: GR
authors.lastname: Armôa
authors.forename: Adriano S
authors.initials: AS
authors.lastname: Campos
authors.forename: Marisa
authors.initials: M
authors.lastname: Farber
authors.forename: Johnjoe
authors.initials: J
authors.lastname: McFadden
authors.forename: Odir Antônio
authors.initials: OA
authors.lastname: Dellagostin
mesh_terms: D042322:Anaplasma marginale; D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D001500:BCG Vaccine / Q000235:genetics / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002417:Cattle; D003001:Cloning, Molecular; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009163:Mycobacterium bovis / Q000235:genetics / Q000276:immunology*
chemical_list: D001500:BCG Vaccine; D001425:Bacterial Outer Membrane Proteins; C449089:major surface protein 1a, Anaplasma