HSP81.2 from Arabidopsis thaliana enhances the immune response against NcSAG1 from Neospora caninum protein and partially protects mice from congenital neosporosis

BENGOA LUONI, SOFIA A; CORIGLIANO, MARIANA G; CLEMENTE, MARINA; SANDER, VALERIA A

Madrid

Congreso; 4th International Meeting on Apicomplexa in Farm Animals, 11-14 October 2017 - Madrid, Spain; 2017

Neosporosis is caused by Neospora caninum, the main pathogen agent responsible for economiclosses in the cattle industry. Currently, thereare not cost-effective control options for neosporosis, and the development ofa vaccine appears to be the best approach. In this study we administrateda novel vaccine formulation including the well characterized major surfaceantigen of N. caninum (NcSAG1) and asadjuvant the 81 KDa heat shock protein (HSP81.2) from Arabidopsis thaliana in a murine model of congenital neosporosis. Both proteinswere expressed in Escherichia coli. BALB/cfemale mice were i.p. immunized on 0 and 15 dpi with a combination of equimolarquantities of rNcSAG1(10 µg) and rAtHSP81.2(30 µg) or each protein alone.Control group was administered 200µl of PBS. Mice were bled on 0, 15, 30, 60and 90 dpi to determine total Immunoglobulin G (IgGt), IgG1 and IgG2a. On 60dpi, mice were mated. Five pregnant mice per group were s.c. challenged with2.106 NC-1 N. caninum tachyzoiteson day 7.5-10.5 after vaginal plug was observed. Five pregnant mice from thecontrol group were not challenged. The offspring were euthanized 60d of age. HighIgGt, IgG1 and IgG2a specific antibody levels directed against rNcSAG1 proteinwere developed by the group that received the combined vaccine formulation andtheir offspring showed improved survival rates. In conclusion, therNcSAG1+rAtHSP81.2 vaccine was able to induce an important humoral response inimmunized mice and confers partial protection against N. caninum to their offspring encouraging us to further study itseffectiveness against congenital neosporosis.