Characterization of the conserved regions of E1A protein from human adenovirus for reinforcement of cytotoxic T lymphocytes responses to the all genogroups causes ocular manifestation through an in silico approach

Iran J Microbiol. 2022 Oct;14(5):746-758. doi: 10.18502/ijm.v14i5.10971.

Abstract

Background and objectives: Adenovirus species B, C, D, and E are the most common causes of ocular manifestations caused by adenoviruses. FDA-approved treatment agents for adenovirus infections are not available. Cell-mediated immunity is the major protective mechanism versus human adenoviruses (HAdVs) infection and T cells specific for peptide epitopes from nonstructural proteins can prevent adenoviral dissemination. E1A CR2 region of HAdVs Epitopes predicted for reinforcing cytotoxic T lymphocytes (CTLs) in the EKC patients. Among human adenoviruses E1 protein, four distinct E1A regions had a significantly higher level of homology than the rest of E1A protein. E1A protein inhibits IFN signal transduction. Epitope-based vaccines are designed to have flexible and simple methods to synthesize a vaccine, using an adjuvant to trigger fast immune responses. CTL epitopes were applied to create a multiepitope vaccine. Conserve region1 (CR1) and CR3 have less antigenicity compared to CR2. Additionally, CR3 in HAdV-D8 contains three toxic areas. CR4 similar to the two regions CR1 and CR3 do not show acceptable antigenic properties.

Materials and methods: Bioinformatics' tools were used to predict, refine and validate the 3D structure of the construct. Effective binding was predicted by protein-protein docking of the epitope vaccine with MHC-I molecules and revealed the safety and efficacy of the predicted vaccine construct.

Results: In silico analysis show that rising levels of cytotoxic CD8 + T cells, TH1 cells, macrophages, and neutrophils are linked to IFN-dominant TH1-type responses, which are detected in putative immune individuals.

Conclusion: Combined with 3D protein modeling, this study predicted the epitopes of E1A CR2 protein in HAdVs.

Keywords: Adenovirus E1A proteins; Cytotoxic T-lymphocyte; In silico model; Keratoconjunctivitis; Molecular docking.