At least one YMHCI molecule in the chicken is alloimmunogenic and dynamically expressed on spleen cells during development.
Transcriptionally active, MHC class I (MHCI) loci are located in two separate polymorphic genomic regions in the chicken called B and Y. The YMHCI gene sequences encode molecules with uncommon substitutions in the antigen-binding region indicating that YMHCI molecules are likely unique and may bind a specialized form of antigen distinct from that of other antigen-binding MHCI molecules. To learn whether YMHCI gene expression results in the production of alloantigens at the cell surface, we immunized 15I(5) x 7(2) : chickens using syngeneic RP9 cells expressing transduced YF1w*7.1, a potentially alloimmunogenic YMHCI allele from the Y7 haplotype present in line C. The resulting antisera show that YF1w*7.1 MHCI molecules are immunogenic and expressed on the surfaces of cells in blood and spleen of line C chickens. Virtually all CD3+, CD4+, and CD8+ cells circulating in line C blood are positive, as are BU1+ cells. The YF1w*7.1 MHCI allele is dynamically expressed at levels comparable to but transcriptionally independent of classical BMHCI on erythrocytes, lymphocytes, granulocytes, monocytes, and thrombocytes within the spleen pre- and post-hatching. The antisera react with cells from two among four haplotypes segregating in closed populations of lines N and P. YMHCI shares features associated with both classical and non-classical MHCI. It is becoming increasingly likely that YMHCI has a fundamental role in avian immunity and thereby needs to be included in the growing spectrum of functionally active, diverse MHCI molecules no longer adequately described by the classical/non-classical dichotomy.
Hunt
Henry D
HD
Avian Disease and Oncology Laboratory, Agricultural Research Service, USDA, 3606 East Mount Hope Road, East Lansing, MI 48823, USA. hunthd@MSU.edu
Goto
Ronald M
RM
Foster
Douglas N
DN
Bacon
Larry D
LD
Miller
Marcia M
MM
D000818:Animals; D030801:Animals, Genetically Modified; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002642:Chick Embryo / Q000254:growth & development*; D000939:Epitopes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D005805:Genes, MHC Class I; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007106:Immune Sera / Q000276:immunology; D012150:Polymorphism, Restriction Fragment Length; D013154:Spleen / Q000196:embryology / Q000378:metabolism*; D014162:Transfection
D000939:Epitopes; D015395:Histocompatibility Antigens Class I; D007106:Immune Sera