Humoral immune response in ewes and maternal passive transfer after immunization with polymeric BLSOmp31 formulated with a nanostructureformed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16)

DÍAZ A.G.; SANCHEZ VALLECILLO M.F.; PARDO, R.; MALETTO B.A.; PALMA S.; ALLEMANDI D; GOLDBAUM F.A; ESTEIN S.M

Buenos Aires

Congreso; LXIII Reunión anual de SAI; 2015

Brucellaovis causes reproductive failure in sheepwith significant economic losses. The only available vaccine is an attenuated strain which shows important disadvantages. Consequently, there is a need for developing of safe andefficient brucellosis vaccines. Previous studies demonstrate that polymeric BLSOmp31 was immunogenic and conferred protection against B. ovis infection in rams.The aim of this study was toanalyze thehumoral immune response induced in pregnant ewes in serum, secretions and milk after immunization with BLSOmp31 using Coa-ASC16 asvaccine platform.Twelve pregnant ewes were randomly distributed in two groups immunized with BLSOmp31/Coa-ASC16 (0.5 mg/animal) bysubcutaneous(n=5) (G1) orby conjunctivalroute (n=5) (G2)twice (days 0 and 21).Nonimmunizedgroup was included (n=2) (G3). Samples of sera, saliva, lacrimal, nasal and vaginal secretions were obtained periodically until day 80. After parturition samples of milk were obtained and lambs were bled for obtaining sera. All samples wereanalyzedby ELISA anti-BLSOmp31 to determine specific IgG antibodies.The immunization of ewes with BLSOmp31/Coa-ASC16 by subcutaneous route induced higher levels of antibodies in serum than conjunctival administration until day 60 while both of them were similar at day 80. No levels of IgG antibodies were detected in any secretion. Milk samples and sera from lambs showed significant levels of IgGantibodies which were higher in ewes immunized by subcutaneous route.These results suggest that vaccination of ewes with BLSOmp31/Coa-ASC16 offers an alternative to induce passive immunity which could help to prevent B. ovis infection in lambs.