Humoral and cellular immune response induced by the chimeric BLSOmp31 vaccine in ovine brucellosis

DÍAZ A.G.; CLAUSSE M.; PAOLICCHI F.A.; FIORENTINO M.A.; GHERSI G.; ZYLBERMAN V.; GOLDBAUM F.A.; ESTEIN S.M.

La Habana

Conferencia; Modern biotechnologies for animal health. Biotecnología Habana 2011.; 2011

Center for Genetic Engineering and Biotechnology

Brucella ovis is the etiologic agent of ovine brucellosis. Control measures include culling of animals positive to serological tests and/or bacteriological culture. Vaccination with B. melitensis Rev 1 gives protection against B. ovis but it has important disadvantages. Consequently, there is a need for new brucellosis vaccines to be developed. We have previously reported that the polymeric subcellular vaccine BLSOmp31 confers protection against experimental challenge with B. ovis in rams and it is a safe alternative to control of this disease. The aim of this work was to evaluate in rams: A) the humoral and in vivo cellular immune response induced by BLSOmp31 using different doses of chimeric BLSOmp31 (200 μg, 300 μg or 500 μg) administered alone or with different adjuvants (Quil A or Incomplete Freund Adjuvant (IFA)) two times with an interval of 4 weeks between immunizations by parenteral injection, ii) the humoral, in vivo and in vitro cellular immune response induced by the best formulation used in A). Sera reactivities against BLSOmp31 antigen were determined by specific I-ELISA. Cellular immune responses were explored by intradermal testing with chimera and/or determination of IFN- in supernatant of stimulated whole blood culture. Independently of the doses evaluated, soluble BLSOmp31 did not induce IgG specific antibodies or increase in skin thickness. BLSOmp31-IFA formulation elicited higher and more homogeneous specific humoral and in vivo cellular immune responses as compared with chimera in Quil A when 500 μg doses were used. Only rams immunized exhibited a marked local increase in skin thickness and showed the highest levels of IFN-g when compared with nonimmunized rams. As described in previous reports(1), we found that the higher dose of chimera formulated in IFA induced the best and well balanced immune response in sheep in the period evaluated. (silmares@vet.unicen.edu.ar)