Isolation and characterization of a pig major histocompatibility complex (SLA) class II DNA cDNA clone

Nomenclature for factors of the swine leukocyte antigen class II system, 2005

A systematic nomenclature for the genes and alleles of the swine major histocompatibility complex (MHC) is essential to the development and communication of research in swine immunology. The Swine Leukocyte Antigen (SLA) Nomenclature Committee of the International Society for Animal Genetics (ISAG) has reviewed all of the DNA-sequence information for MHC class II genes, available in GenBank/EMBL/DDBJ databases, and the associated published reports to develop such a systematic nomenclature. This article summarizes the proposed nomenclature, which parallels the World Health Organization's nomenclature for factors of the human MHC. The SLA class II genes expressed on the cell membrane will be noted as SLA-DRA, SLA-DRB1, SLA-DQA, and SLA-DQB1. Nomenclature assignments for all SLA class II GenBank sequences are now noted. The committee will add new SLA class II allele designations, as they are discovered, and will maintain a publicly available list of all recognized genes and alleles using the Immuno Polymorphism Database (IPD). The sequences will be available from the IPD-MHC section of the database which contains non-human MHC sequences (http://www.ebi.ac.uk/ipd/mhc/sla/).

Differential alloreactivity at SLA-DR and -DQ matching in two-way mixed lymphocyte culture

The major histocompatibility complex (MHC) class II molecules are heterodimeric cell surface glycoproteins important for antigen presentation to CD4+ T lymphocytes. Class II molecules of the pig MHC, termed SLA, identified so far include DR and DQ. Thus far, functional differences between products of different loci in SLalpha class II have not been well characterized. For detailed research on this issue, SLalpha-DRbeta1 and -DQbeta typings were newly developed by restriction fragment length polymorphism (RFLP) of the reverse transcriptase-polymerase chain reaction (RT-PCR) products. Using this method, several RFLP types were chosen from 13 CSK miniature pigs, and alloreactivities in two-way mixed lymphocyte culture (MLC) derived from these pigs were examined by cell proliferation assay using flow cytometry. The responses in MLC varied according to the degree of phenotype difference. In MLC from individuals of the same RFLP type in both SLA-DRbeta1 and -DQbeta, the proliferative responses showed slight reaction indicating that they were not so stimulated by each other. On the other hand, for the RFLP type-mismatching combination, the responses were strong indicating that they recognized each others alloantigens. The reactivity of only the DQbeta mismatching combination was as strong as those of only the DRbeta1 mismatching combination. These data indicate the important role of the DQ as well as DR molecule on alloreactivity in MLC.

Cattle MHC genes DOA and DOB: sequence polymorphisms and assignments to the class IIb region

In a study of the genetic polymorphism of the second exons of the cattle DOA and DOB genes, two and four allelic variants were detected, respectively. In the predicted amino acid sequence, the DOA polymorphism corresponded to variation at the respective residue position, whereas the nucleotide substitutions in the DOB gene were non-informative. PCR-RFLP assays were developed for DOA and DOB typing, and both loci were genetically mapped to the BoLA class IIb region by linkage analysis in the International Bovine Reference Panel. The single nucleotide polymorphisms detected in the BoLA-DOA and -DOB genes enable these loci to be used as markers in genetic trait analyses.

cDNA cloning and genetic polymorphism of the swine major histocompatibility complex (SLA) class II DMA gene

cDNA clones corresponding to the swine histocompatibility complex (SLA: swine leucocyte antigen)-DM alpha chain were isolated using the polymerase chain reaction (PCR) products from the third exon in the human HLA-DMA gene as a probe. Amino acid comparative analysis revealed that these clones were more closely related to the bovine and human DMA genes than to the other swine class II genes alpha chain genes, DRA, DQA and DOA. These results suggest that the SLA-DMA gene is expressed and may function, like HLA-DM, as an important modulator in class II restricted antigen processing in swine. Furthermore, based on the sequences and PCR-restriction fragment length polymorphism (PCR-RFLP) patterns in the SLA-DMA gene, no allelic variation was recognized in the second exon, but five allelic variations were recognized in the third exon in five different breeds of swine. These DMA alleles were defined by variation at four nucleotide positions. Two of these alleles resulted in an amino acid substitution. These results suggest that SLA-DMA has little polymorphism as observed in HLA-DMA and mouse H2-Ma.