Evaluation of the protective effect of pVAX-EtMIC3-recombined plasmid against E. tenella in chicken

Abstract

Coccidiosis caused by protozoan parasites of the genus Eimeria has a severe economic impact on commercial production worldwide. Micronemes of Eimeria play important roles in invading intestinal cell processes. In this study, the DNA vaccine expressing Eimeria tenella microneme protein 3 (EtMIC3) was constructed to evaluate its immune protective effect against E. tenella infection in chickens. The results demonstrated that chickens immunized with pVAX-EtMIC3 produced strong immune responses in the body, as shown by significant lymphocyte proliferation, cytokine production, and antibody responses. The average body weight gains of chickens in all the vaccinated groups were higher than those of non-vaccinated and challenged groups. In general, oocyst shedding was reduced, and bloody feces and gut lesion scores decreased. In addition, the survival rate of the immunized chickens increased compared to that of the unvaccinated and challenged control chickens. In summary, this study indicated that pVAX-EtMIC3 could induce protective immune effects against coccidiosis and that EtMIC3 is a potential vaccine candidate against coccidiosis.

Probiotic Enterococcus faecalis surface-delivering key domain of EtMIC3 proteins: immunoprotective efficacies against Eimeria tenella infection in chickens

“…In this study, the levels of antigen-specific IgG in sera and sIgA in cecal lavage fluids elicited by the four recombinant E. faecalis expressing BC1 or C4D proteins were higher than those in the PBS and vector groups ( P < 0.01), indicating that recombinant bacteria indeed stimulate significant humoral immune responses. Moreover, BC1 or C4D protein fused with DCpep induced higher levels of IgG and sIgA than BC1 or C4D protein alone delivered by E. faecalis , respectively ( P < 0.05), indicating that DCpep effectively improved the target delivery of BC1 or C4D antigens to dendritic cells, increased uptake and antigen presentation, and offered more protective efficacies against homologus challenge, which are consistent with previous reports ( 11 , 21 ).…”

Vaccination Against Poultry Parasites

“…For this reason, proteins expressed in the microneme, the organelle of sporozoites and merozoites involved in host invasion, have frequently been investigated. Microneme proteins (MICs) EaMIC2 (60), EaMIC3 (61), EaMIC5 (62) of E. acervulina ; EmiMIC3 of E. mitis (63); EmMIC2 (64) and EmMIC7 (65) of E. maxima ; and EtMic1 (66), EtMIC2 (67), EtMIC3 (68), and EtMIC8 (30) of E. tenella all have induced an immune response and some degree of protection. Functionally related to MICs are rhomboid-like proteins, which cleave MICs, a necessary step in host cell invasion.…”