title: Expression of Babesia bovis rhoptry-associated protein 1 (RAP1) in Brucella abortus S19.
abstract: Brucella abortus strain 19 (live vaccine) induces a strong humoral and cellular immune response and therefore, it is an attractive vector for the delivery of heterologous antigens. The objective of the present study was to express the rhoptry-associated protein (RAP1) of Babesia bovis in B. abortus S19, as a model for heterologous expression of immunostimulatory antigens from veterinary pathogens. A plasmid for the expression of recombinant proteins fused to the aminoterminal of the outer membrane lipoprotein OMP19 was created, pursuing the objective of increasing the immunogenicity of the recombinant antigen being expressed by its association to a lipid moiety. Recombinant strains of B. abortus S19 expressing RAP1 as a fusion protein either with the first amino acids of beta-galactosidase (S19pBB-RAP1) or B. abortus OMP19 (S19pBB19-RAP1) were generated. Plasmid stability and the immunogenicity of the heterologous proteins were analyzed. Mice immunized with S19pBB-RAP1 or S19pBB19-RAP1 developed specific humoral immune response to RAP1, IgG2a being the predominant antibody isotype. Furthermore, a specific cellular immune response to recombinant RAP1 was elicited in vitro by lymphocytes from mice immunized with both strains. Therefore, we concluded that B. abortus S19 expressing RAP1 is immunostimulatory and may provide the basis for combined heterologous vaccines for babesiosis and brucellosis.
authors.affiliation: Instituto de Biotecnología, CICVyA, INTA-Castelar, Las Cabañas y Los Reseros s/n (B1712WAA) Castelar, Buenos Aires, Argentina.
authors.forename: Julia V
authors.initials: JV
authors.lastname: Sabio y García
authors.forename: Marisa
authors.initials: M
authors.lastname: Farber
authors.forename: Mariela
authors.initials: M
authors.lastname: Carrica
authors.forename: Silvio
authors.initials: S
authors.lastname: Cravero
authors.forename: Gilson C
authors.initials: GC
authors.lastname: Macedo
authors.forename: Fabiana
authors.initials: F
authors.lastname: Bigi
authors.forename: Sergio C
authors.initials: SC
authors.lastname: Oliveira
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Rossetti
authors.forename: Eleonora
authors.initials: E
authors.lastname: Campos
mesh_terms: D000818:Animals; D016793:Babesia bovis / Q000235:genetics*; D001404:Babesiosis / Q000276:immunology / Q000517:prevention & control; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D002004:Brucella Vaccine / Q000276:immunology; D002003:Brucella abortus / Q000235:genetics / Q000378:metabolism*; D002006:Brucellosis / Q000276:immunology / Q000517:prevention & control; D005822:Genetic Vectors; D051379:Mice; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002004:Brucella Vaccine; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D017778:Vaccines, Combined; C097551:rhoptry-associated protein-1, Babesia