The Avian MHC-Antigen System

Abstract Background The Major Histocompatibility Complex (MHC) codes for the key vertebrate immune receptors responsible for pathogen recognition. Foreign antigens are recognized via their compatibility to hyper-variable region of the peptide-binding groove (PBR), which consists of two separate protein domains. Specifically, the PBR of the MHC class I receptors, which recognize intra-cellular pathogens, has two α domains encoded by exon 2 (α1) and exon 3 (α2) of the same gene. Most research on avian MHC class I polymorphism has traditionally focused exclusively on exon 3 and comparisons of selection between the two domains have been hampered by the scarcity of molecular data for exon 2. Thus, it is not clear whether the two domains vary in their specificity towards different antigens and whether they are subject to different selective pressure. Results Here, we took advantage of rapidly accumulating genomic resources to test for the differences in selection patterns between both MHC class I domains of the peptide-binding groove in birds. For this purpose, we compiled a dataset of MHC class I exon 2 and 3 sequences for 120 avian species from 46 families. Our phylogenetically-robust approach provided strong evidence for highly consistent levels of selection on the α1 and α2 domains. There were strong correlations in all selection measures (number of positively/negatively selected residues and dN/dS ratios) between both PBR exons. Similar positive associations were found for the level of amino acid polymorphism across the two domains. Conclusions We conclude that the strength of selection and the level of polymorphism are highly consistent between both peptide-binding domains (α1 and α2) of the avian MHC class I.

Download Full-text

Biochemical and functional characteristics of class II MHC antigen (Ia) on freshly-prepared Langerhans cells (fLC) and cultured Langerhans cells (cLC)

Journal of Dermatological Science ◽

10.1016/0923-1811(91)90113-c ◽

1991 ◽

Vol 2 (3) ◽

pp. 227

Author(s):

Setsuya Aiba ◽

Stephen I. Katz

Keyword(s):

Langerhans Cells ◽

Class Ii ◽

Functional Characteristics ◽

Class Ii Mhc ◽

Mhc Antigen

Download Full-text

LYMPHOID CELL REGULATION OF MHC ANTIGEN EXPRESSION ON TERATOCARCINOMA CELLS IN VlVO

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1982.tb36141.x ◽

1982 ◽

Vol 392 (1 Immunological) ◽

pp. 407-407

Author(s):

Suzanne Ostrand-Rosenberg ◽

Allen Cohn

Keyword(s):

Lymphoid Cell ◽

Antigen Expression ◽

Cell Regulation ◽

Teratocarcinoma Cells ◽

Mhc Antigen

Download Full-text

Class I MHC Antigen Processing

Immunodominance ◽

10.1002/3527608028.ch1 ◽

2006 ◽

pp. 1-30

Author(s):

Peter J. Miller ◽

Edward J. Collins

Keyword(s):

Antigen Processing ◽

Class I ◽

Class I Mhc ◽

Mhc Antigen

Download Full-text

Introduction to the Hla Antigen System

HLA and Disease: A Comprehensive Review ◽

10.1201/9781351073226-1 ◽

2019 ◽

pp. 1-21

Author(s):

William E. Braun

Keyword(s):

Hla Antigen ◽

Antigen System

Download Full-text

Biallelic neutrophil Na-antigen system is associated with a polymorphism on the phospho-inositol-linked Fc gamma receptor III (CD16)

Blood ◽

10.1182/blood.v75.1.213.bloodjournal751213 ◽

1990 ◽

Vol 75 (1) ◽

pp. 213-217 ◽

Cited By ~ 1

Author(s):

TW Huizinga ◽

M Kleijer ◽

PA Tetteroo ◽

D Roos ◽

AE von dem Borne

Keyword(s):

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Specific Antigen ◽

Phosphatidyl Inositol ◽

Structural Features ◽

Fc Gamma Receptor ◽

Gamma Receptor ◽

Sds Page ◽

Antigen System ◽

Genetically Determined

Neutrophils express two distinct types of receptor for the Fc region of IgG, FcRII and FcRIII, in amounts of 10,000 to 20,000 FcRII (40 Kd) and 100,000 to 200,000 FcRIII (50 to 80 Kd) per neutrophil. We showed that the FcRIII exhibits genetically determined heterogeneity, detectable by differences in electrophoretic mobility with sodium dodecyl sulfate (SDS) as well as by reaction with antibodies against the biallelic neutrophil-specific antigen system NA. FcRIII was precipitated with an FcRIII-specific monoclonal antibody (MoAb) from the neutrophils of 35 donors. NA1NA1 donors expressed an FcRIII with a molecular weight (mol wt) of 50 to 65 Kd, NA1NA2 donors expressed an FcRIII with a mol wt of 50 to 80 Kd, and NA2NA2 donors expressed an FcRIII with a mol wt of 65 to 80 Kd. Statistical analysis showed that the electrophoretic heterogeneity corresponds with the NA polymorphism (k = 1). Sequential immunoprecipitation with a MoAb against NA1 and a MoAb against anti- FcRIII, followed by SDS-polyacrylamide gel electrophoresis (PAGE), showed that NA1-FcRIII is distinct from NA2-FcRIII. Moreover, immunoprecipitation with a MoAb against NA1 yielded a protein of 50 to 65 Kd, and immunoprecipitation with human anti-NA2 sera or an MoAb against NA2 yielded a protein of 65 to 80 Kd. Preincubation of NA1NA2 neutrophils with F(ab')2 fragments of an MoAb against anti-NA1 reduced binding of IgG dimers to these cells with about 50%, whereas it completely prevented binding of the dimers to NA1NA1 neutrophils. Inhibition experiments with the MoAb against NA2 yielded the same results for NA1NA2 cells, whereas binding of IgG dimers to NA2NA2 cells was completely prevented. Thus, the products of both NA alleles bind IgG. Immunoprecipitation from the medium of neutrophils either stimulated with formyl- methionyl-leucyl-phenylalanine (FMLP) or treated with glycosyl-phosphatidyl-inositol-specific phospholipase C (GPI- PLC) showed that both the NA1-FcRIII and the NA2-FcRIII are released from the cell surface, indicating that both forms of FcRIII have some structural features in common. Deglycosylation of FcRIII from homozygous donors yielded material that showed several bands on SDS- PAGE. GPI-PLC treatment of neutrophils indicated that all of this material is phosphatidyl-inositol linked.

Download Full-text