Specialized Antigen Presentation by YF MHC Class I-Like Molecules in Poultry Health

Genetic selection is a powerful means for increasing poultry health.  For example, particular haplotypes in the MHC-B region (containing loci for peptide antigen presentation and the BG genes) are routinely selected in commercial breeding stocks to take advantage of the contribution of genes within the MHC-B region in reducing the incidence of Marek’s disease.  Genes in the nearby polymorphic MHC-Y region (inherited independently from MHC-B because of an intervening recombination hotspot) encode specialized class I-like molecules (YF molecules).  The polymorphic nature of expressed YF genes and the structural similarity known between the YF isoform YF1*7.1 and mammalian MHC class I-like molecule MR1 have led us to postulate that chicken YF molecules have a specialized role in immune defense.  We postulate that YF molecules function in early immunity in the “middle ground” between the earliest innate immune responses and the later responses controlled through adaptive (memory-based) immunity.  Results of experiments to define the nature of YF ligands will be presented in this station report.