Integrated analysis on immunoreactivity and immunogenetics of Hantaan virus glycoprotein epitopes.

As a bridge between humoral and cellular immunity in the body, CD4+ T cells play an important role in the clearance of Hantaan virus (HTNV) infection. The envelope-anchored glycoprotein (GP) is responsible for orchestrating host cell entry and fusion. In the bioinformatics stage of this study, we assessed 22 dominant B-cell epitopes and 191 T-cell epitopes (including MHC-I and MHC-II restricted) covering MHC genotype frequencies ≥30% in various regions worldwide, using multiple prediction algorithms and HLA population-frequency criteria. Through affinity analysis and molecular docking, the relationship between nonapeptide determinants and 15-mer epitopes suggested that consecutive CD4+ T-cell epitopes may share a nonapeptide that plays a major binding role in multiple HLA genotypes. Sequence alignment of the reported viral variants showed that affinity changes of non-conserved epitopes were tiny in either humoral or cellular immunity. Toxicity and allergenicity screening identified 23 peptides as safe and available to the body. Based on these bioinformatics predictions, we selected candidate peptides for experimental validation. In the wet-lab stage, specialized immunological assays (ELISA and ELISpot) were performed using human peripheral blood samples from vaccinated volunteers, and anti-HTNV humoral and cellular immune epitopes were validated. The results are strongly representative in a certain population and HLA genotypes. Our research is grounded in HTNV GP and provides a theoretical basis for the use of epitopes in the prevention and control of HTNV. More importantly, studies of T-cell and B-cell epitopes from multiple dimensions and perspectives would further deepen the understanding of peptide-based immunotherapy against emerging viral infections and accelerate the development of global public health services.