Charactreization of polymorphism within theH-2MMHC class II loci

✍ Scribed by Evan Hermel; Jie Yuan; John J. Monaco

• Book ID: 104652780
• Publisher: Springer-Verlag
• Year: 1995
• Tongue: English
• Weight: 712 KB
• Volume: 42
• Category: Article
• ISSN: 0093-7711
• DOI: 10.1007/bf00178588

✦ Synopsis

The products of the class II-like H2-M genes of the major histocompatibility complex are required for class II antigen processing. We sequenced H2-Ma and Mb from several mouse strains to determine whether these genes are polymorphic like the classical H2-A and E genes, or are oligomorphic, like H2-O. Both Mb loci appear to be transcribed and are distinct from each other. Mbl and Mb2 differ by about 11% at the nucleotide level and are most dissimilar in their second exons (corresponding to the [31 domain). Relative to the published Mbl d haplotype sequence, the products of the b, g7, f, and k2 alleles of Mb 1 from Mus musculus domesticus and the separate mouse species Mus spretus differ by only one to four amino acids. The majority of the changes occurred in the second exon of Mb 1, in contrast to HLA-DMB, the human orthologue. Little polymorphism was seen for Mb 2, and Ma was invariant in all strains tested. The similarity of the g7 allele to those from other haplotypes makes it unlikely that the M class II genes play a role in the autoimmune diabetes of NOD strain mice. The M genes are regulated in a manner similar to classical class II genes, in that they are upregulated by IFN-2' in macrophages, and to a lesser extent by IL4 in B cells. When modeled on the crystal structure of the HLA-DR1 class II molecule, nearly all of the differences between MI31 and MI32 affect residues facing away from the putative peptide binding groove.