The
infections of chicken
coccidiosis impact the welfare of chickens and the economical production of poultry. Eimeria mitis is ubiquitous in chicken
coccidiosis, and E. mitis
infection can significantly affect the productivity of birds. Up to now, few efficient
vaccines against E. mitis have been reported, whereas the recombinant
subunit vaccines delivered by nanomaterials may elicit an encouraging outcome. Thus, in this study, we chose E. mitis 1a (Em1a)
protein as the candidate
antigen to generate Em1a preparations. The recombinant Em1a (rEm1a)
protein was encapsulated with
poly lactic-co-glycolic acid (PLGA) and
chitosan (CS)
nanospheres. The physical characterization of the rEm1a-PLGA and rEm1a-CS
nanospheres was investigated, and the resulting
nanospheres were proven to be nontoxic. The protective efficacy of rEm1a-PLGA and rEm1a-CS preparations was evaluated in E. mitis-challenged birds in comparison with two preparations containing rEm1a
antigen emulsified in commercially available adjuvants. ELISA assay, flow cytometry analysis, and quantitative real-time PCR (qPCR) analysis indicated that vaccination with rEm1a-loaded
nanospheres significantly upregulated the secretions of
antibodies and
cytokines and proportions of CD4+ and CD8+ T lymphocytes. Compared with the other three preparations, rEm1a-PLGA
nanosphere was more effective in improving growth performance and inhibiting oocyst output in feces, indicating that the PLGA
nanosphere was associated with optimal protection against E. mitis. Collectively, our results highlighted the advantages of
nanovaccine in eliciting protective immunity and may provide a new perspective for developing effective
vaccines against chicken
coccidiosis.