Designing T-cell epitope-based vaccine against Eimeria infection in chicken using immunoinformatics approach.

Abstract

Chicken coccidiosis is the most significant ubiquitous, intestinal parasitic disease known to infect chickens globally. It is recognised for incurring significant production loss to the poultry industry, caused by single or multiple Eimeria spp. infections which threaten chicken welfare and productivity. The emergence of drug resistance in parasites and pathogenicity reversion has put pressure on the poultry industry to reduce chemoprophylactic drugs and live vaccines as preventive measures against coccidiosis. Recombinant DNA vaccines have shown promising results as an alternative option, but complete protection has not been reported highlighting the need for the design of new vaccine against this disease. In this study, Eimeria antigens Immune Mapped Protein-1(IMP1) and Microneme Protein-2(MIC2) were explored using reverse vaccinology and immunoinformatics tool to predict and design potential multiepitope vaccine candidate against coccidiosis. A total of 28 and 19 antigenic T-cell epitopes were predicted and used to construct two multiepitope vaccines with 610 and 512 amino acids for IMP1 and MIC2, respectively. The produced vaccines exhibited favoured characteristics for an ideal vaccine candidate; they were antigenic (Vaxijen score of 0.5989 and 0.5103), immunogenic (scores: 10.15 and 9 419), thermostable (instability index <40 ), and non-allergic. The presence of IFN-gamma and IL-4 inducing epitopes in the constructed vaccine enables vaccine to trigger a cellular and humoral response within the host. Molecular docking of designed vaccines with toll-like receptors (TLR4 and TLR5) to determine vaccine interaction and stability was confirmed by molecular dynamics simulation root-mean square deviation (RMDS) and root-mean-square fluctuation (RMSF) analysis. The designed vaccines induced immune response through production of cytokines and antibodies associated with tertiary response. When exposed to online immune simulation C-ImmSim, both vaccines produced potent immune response through production of IgG, Tc and Th cell and memory Bcells. The constructed multiepitope vaccine in this present study is highly promising and as such further experimental work should be done to confirm its suitability against chicken coccidiosis.