Structural and Biochemical Analyses of Swine Major Histocompatibility Complex Class I Complexes and Prediction of the Epitope Map of Important Influenza A Virus Strains

Abstract

We crystalized and solved the first SLA-3 structure, SLA-3*hs0202, and found that it could present the same IAV peptide with two distinct conformations. Unlike previous findings showing that variable peptide conformations are caused only by the flexibility of the side chains in the groove, the skewing of the α1 and α2 helixes is important in the different peptide conformations in SLA-3*hs0202. We also determined the fundamental motif for SLA-3*hs0202 to be X-(M/A/R)-(N/Q/R/F)-X-X-X-X-X-(V/I) based on a series of structural and biochemical analyses, and 28 SLA-3*hs0202-restricted epitope candidates were identified from important IAV strains. We believe our structure and analyses of pSLA-3*hs0202 can benefit vaccine development to control IAV in swine.