Probioticsurface-delivering key domain of EtMIC3 proteins: immunoprotective efficacies againstinfection in chickens.

Abstract

Avian coccidiosis caused bybrings huge economic losses to the poultry industry. Although live vaccines and anti-coccidial drugs were used for a long time,infection in chicken farms all over the world commonly occurred. The exploration of novel, effective vaccines has become a research hotspot.parasites have complex life cycles, and effective antigens are particularly critical to developing anti-coccidial vaccines. Microneme proteins (MICs), secreted from microneme organelles located at the parasite apex, are considered immunodominant antigens.microneme 3 (EtMIC3) contains four conserved repeats (MARc1, MARc2, MARc3, and MARc4) and three divergent repeats (MARa, MARb, and MARd), which play a vital role during theinvasion.is a native probiotic in animal intestines and can regulate intestinal flora. In this study, BC1 and C4D domains of EtMIC3, BC1 or C4D fusing to dendritic cells targeting peptides, were surface-displyed byrespectively. Oral immunizations were performed to investigate immune protective effects againstinfection.