Protection of chimeric subcellular vaccines against Brucella ovis in rams

ESTEIN S., FIORENTINO A, PAOLICCHI F, CLAUSSE M, MANAZZA J, CASSATARO J, GIAMBARTOLOMEI

Tandil

Otro; XL Reunión Sociedad Argentina de Farmacología Experimental 2008; 2008

PROTECTION OF CHIMERIC SUBCELLULAR VACCINES AGAINST BRUCELLA OVIS IN RAMS Estein S1*, Fiorentino A2, Paolicchi F2, Clausse M1, Manazza J2, Cassataro J3, Giambartolomei G3, Coria L3, Zylberman V4, Fossati C3, Goldbaum F4 1Lab. de Inmunología, F.C.V., U.N.C.P.B.A..,Pinto 399, Tandil, Bs. As., Argentina, silmares@vet.unicen.edu.ar; 2Lab. de Bacteriología, INTA-Balcarce; 3IDEHU-CONICET, FFyB, U.B.;, 4Fundación Instituto Leloir. Chimera BLS-OMP31 as a recombinant protein (rBLS-Omp31) or DNA vaccine (pCIbls-Omp31) has been identified as a protective antigen against B. ovis in mice. In this work, groups of 10 rams were vaccinated three times with: a) Chimera in oil based adjuvant (IFA), b) Chimera in saponin (QUIL A), c) DNA with electro-poration, d) DNA without electroporation and e) Prime-boost (PB) (3 times with electroporated DNA, and a fourth with protein). Control group was immunized with hot saline extract (HS) of B. ovis. Unvaccinated group was included. Rams were challenged with virulent B. ovis 7 months after last immunization and slaughtered 6 months thereafter, taking bacteriological samples from 12 organs. Chimera in IFA and PB strategy induced the highest IgG specific antibodies followed by chimera in QUIL A. Electroporation enhanced humoral immune response in DNA vaccinated rams. However PB stimulated the best levels of specific gamma IFN. The highest rates of protection were obtained with PB (75%) and chimera with IFA (63%). In the other groups the level of protection remained between 10-20 %, including HS vaccine. Percentages of infection in unvaccinated rams and DNA without electroporation were 100%. Altogether these results indicate that chimera should be considered as potential vaccine in ovine brucellosis.