However, no T cell epitope of H5N1 AIV NP has yet been identified in the chicken [7] , while no information is available on the structure of chicken MHC class I molecules belonging to the B4, B12, B15, and B19 haplotypes. For the first time, the current study reports the homology modelling structures of the peptidebinding domains of chicken MHC class I molecules for the B4, B12, B15, and B19 haplotypes. Potential T cell epitopes were predicted by molecular docking of 25 peptides in the H5N1 AIV NP in chicken. NP 89-97 and NP 198-206 were shown to be T cell epitopes of H5 AIV NP by analysing the CD8 + T cell proliferation and the interferon (IFN-c) expression. To our knowledge, this is the first report to describe the structure of chicken MHC class I molecules from the B4, B12, B15 and B19 haplotypes and the T cell epitopes of H5N1 AIV NP in chicken.