Peptide-binding motif prediction by using phage display library for SasaUBA*0301, a resistance haplotype of MHC class I molecule from Atlantic Salmon (Salmo salar)

• Published in: Molecular Immunology
• Main Authors: Zhao, H., Hermsen, G.J., Stet, R.J.M., Skjodt, K., Savelkoul, H.F.J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: anemia-virus; complexes; epitope; histocompatibility class-i; ligands; polymorphism; Atlantic salmon; Salmo salar
• Online Access: https://research.wur.nl/en/publications/peptide-binding-motif-prediction-by-using-phage-display-library-f; https://doi.org/10.1016/j.molimm.2007.10.014

The structure of the peptide-binding specificity of major histocompatibility complex (MHC) class I has been analyzed extensively in human and mouse. For fish, there are no crystallographic models of MHC molecules, neither are there data on the peptide-binding specificity. In this study, we describe for the first time the identification of a fish class I peptide-MHC ligand binding motif. Phage display technology using both 7 mer and 12 mer libraries enabled us to identify peptide ligands with unique specificity that interacts with the recombinant Salmon MHC class I molecule. The recombinant proteins, ß2m/SasaUBA*0301, were produced in Escherichia coli, in which the carboxyl terminus of ß2-microglobulin is joined together with a flexible (GGGGS)3 linker to the amino terminus of the heavy chain. One hundred and seven individual phages bound to ß2m/SasaUBA*0301 were isolated after four rounds of panning from the 7 mer random-peptide library. The peptide encoding sequences were determined and peptide alignment led to the prediction of position-specific anchor residue. A prominent proline at position 2 was observed and we predict that it might be one of the anchors at the N-terminus. Meanwhile, phage display peptide library encoding random 12 mer peptides was also screened against ß2m/SasaUBA*0301. Eighty-five percentages of the corresponding peptides have an enrichment of leucine, methionine, valine, or isoleucine at the C-terminus. We predict that this particular allele of Salmon class I molecule might have a very similar binding motif at the C-terminus compared with a known mouse class I molecule H2-Kb which has L, or I, V, M at p8. Previous work showed that Atlantic Salmon carrying the allele SasaUBA*0301 are resistant to infectious Salmon aneamia virus and there is a significant association between MHC polymorphism and the disease resistance. Therefore, our study might contribute to designing a peptide vaccine against this viral disease.