Immunogenicity of Mycobacterium bovis BCG expressing Anaplasma marginale MSP1a antigen.
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.
Michelon
André
A
Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, 96010-900 Pelotas, RS, Brazil.
Conceição
Fabricio Rochedo
FR
Binsfeld
Pedro Canisio
PC
da Cunha
Cristina Wetzel
CW
Moreira
Angela Nunes
AN
Argondizzo
Ana Paula
AP
McIntosh
Douglas
D
Armôa
Geraldo R G
GR
Campos
Adriano S
AS
Farber
Marisa
M
McFadden
Johnjoe
J
Dellagostin
Odir Antônio
OA
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*
D001500:BCG Vaccine; D001425:Bacterial Outer Membrane Proteins; C449089:major surface protein 1a, Anaplasma