Novel SLA-DR Alleles of Three Chinese Pig Strains and the Related Function in Human T Cell Response

To elucidate the structures of SLA-DR(swine leukocyte antigen DR)genes of three Chinese pig strains (Gz,Bm and Yn),the SLA-DRA and SLA-DRB cDNA were amplified by RT-PCR and subjected to determine the sequences.The whole structures of SLA-DRA alleles are identical among three strains,consisting of 759 nucleotides including an open reading frame(ORF),and are shared with those reported from NIH minipigs SLA-DRA^c and SLA-DRA^d.The same length of the ORF-containing SLA-DRB genes of three Chinese pig strains was also identified.They are composed of 801 nucleotides encoding a xenogeneic antigen molecule of 266 amino acid residues.The nucleotide sequences of the SLA-DRB genes,however,are different when compared either among the three strains or with the published data of SLA-DRB sequences,which allowed our novel SLA-DRB alleles receiving their accession numbers AY102479,AY102480 and AY102481 from the GenBank.This study further reveals that the phylogenic homologies of MHC DR or DR-like genes in structures of nucleotides and deduced amino acids between Chinese pigs(SLA)and human(HLA-DRB1*0901)are better than those between pigs and mice (H-2~b Eβ).High similarities were also found for DRα-DRβ heterodimers between Chinese pigs and human in terms of amino acids sequences critical for binding with human CD4 coreceptor molecule,which are better than those between SLA-DR and H-2 I-E molecules.A functional test indicated that,by cotransfection with Bm-DRA and Bm-DRB genes,the Bm-DR molecule-expressed L929 cells could stimulate human T cells quite well in a xenogeneic reaction in presence of human APCs.Cellular & Molecular Immunology.2004;1 (3):212-218.