RESUMO
The new HLA-DPB1*142:01 allele differs from DPB1*26:01:02 and DPB1*56:01 at codons 65 (I65>L65) and 35 (F35>Y35), respectively.
Assuntos
Alelos , Rejeição de Enxerto , Cadeias beta de HLA-DP/genética , Transplante de Rim , Polimorfismo de Nucleotídeo Único , Sequência de Bases , Códon , Éxons , Evolução Fatal , Teste de Histocompatibilidade , Humanos , Dados de Sequência Molecular , Peru , Alinhamento de Sequência , Análise de Sequência de DNA , Doadores de TecidosRESUMO
Human leukocyte antigen (HLA) class I sequencing typing of a cord blood unit obtained from an Ecuadorian family showed the presence of the recently described A*6836 and B*3922 alleles. Sequences of these two antigens were confirmed and completed. Additionally, a new HLA-B allele, B*3579, was found in the same family, showing a difference of one amino acid residue at position 211 (Ala > Glu) compared with B*3543.
Assuntos
Alelos , Antígenos HLA-A/genética , Antígeno HLA-B35/genética , Análise de Sequência de DNA , Adulto , Sequência de Aminoácidos , Sequência de Bases , Equador , Feminino , Humanos , Recém-Nascido , Dados de Sequência MolecularRESUMO
Type I diabetes is an autoimmune and a polygenic disease, in which MHC-class II genes contribute to 48% of the disease. The aim of the present study, is to provide a guideline to understanding the molecular association of these genes, through the immunogenetic analysis of 3 Latin american mestizo populations. We included 606 individuals, 349 patients with DMDI and 257 healthy controls coming from 3 geographical areas: Mexico City, Mexico; Caracas, Venezuela and Medellin, Colombia. The results clearly indicate that in mestizo groups, the diabetogenic haplotypes are from mediterranean ancestry, while protection is due to Amerindian genes. It was demonstrated that the relevant sequences for IDDM expression are located to DRB1 and DQB1 loci with a minimal contribution of DQA1 residues. The sequences determining peptide recognition and the induction of TH1 cells mediating the cellular autoimmune response are in positions DRB1-57 and 74 (an aspartic acid and a glutamic acid respectively, confer protection), modulated by D-57 in the DQ, 8 chain. These data show that DRB1-DQB1 haplotypes are central for IDDM expression and open new pathways for the disease management.