Computational Optimisation of EtAMA1 Reveals Its Potential as a Vaccine Candidate Against Eimeria tenella

Eimeria tenella is among the most pathogenic chicken-infecting Eimeria species; hence, coccidiosis remains one of the most economically damaging diseases in the poultry industry globally due to poor growth performance, reduced feed efficiency, intestinal pathology, and increased mortality. Conventional control measures, including chemotherapeutic drugs and live-attenuated vaccines, are increasingly limited due to drug resistance, residue concerns, safety concerns, and high production costs, prompting interest in alternative strategies such as apical membrane antigen-1 (AMA1), a conserved and highly immunogenic microneme protein essential for host-cell invasion. Previous studies in Plasmodium, Toxoplasma, and Babesia have demonstrated the successful use of AMA1 in recombinant and immunoinformatic-designed vaccines, underscoring its potential as a cross-species subunit vaccine candidate. This study explored Eimeria tenella AMA1 (EtAMA1) with the aim of investigating the physicochemical and structural properties, identifying antigenic T-cell and B-cell epitopes using immunoinformatic tools and evaluating the effectiveness of EtAMA1 in inducing an immune response within the host. The structural analysis revealed a z-score of -6.86 and a Ramachandran plot of 97.19%. EtAMA1 contained three CD8+, seven CD4+ T-cell epitopes, one linear, and eight discontinuous B-cell epitopes. The ability of EtAMA1 to elicit an immune response was assessed via an in silico immune simulation. The binding interaction energy generated via molecular docking and dynamics simulations indicated a strong binding interaction of EtAMA1 to Toll-like receptor 5. The results indicate that EtAMA1 is a strong vaccine candidate; however, experimental validation is required.