RESUMO
While characterizing exons 2 and 3 of the class I human leukocyte antigen (HLA)-A locus in human lymphocytes, two similar but unexpected PCR products were detected in six samples of Filipino ethnicity. A nucleotide sequence analysis of the two amplicons, tentatively named HLA-COQ and HLA-DEL, rendered them as two novel and seemingly related sequences, both with homology to the gorilla and human major histocompatibility complex (MHC) A locus. Exon 2 is similar to the published human pseudogenes HLA-BEL, HLA-Y, and to primate MHC Gogo-A*0501, differing by 2 bp from HLA-BEL, and HLA-Y, and by 4 bp from Gogo-A*0501. Exon 3 is most similar to HLA-A*2902 and A*310102, differing by 7 bp from A*2902, and by 8 bp from A*31012. Genomic sequence comparison of exons 1 to 8 indicates that their closest published match is to the Gogo-A*0501. Complete typing at the HLA-A, -B, -C, DRB1, and DRB5 loci for the six samples yielded the reoccurring types: HLA-A*3401, -B*1521/1525, -Cw*0403, -DRB1*150201, and DRB5*010101. Thus far, HLA-COQ and HLA-DEL have been detected only in Filipino samples containing these HLA types. The HLA-COQ gene is nonfunctional based on a stop codon located in exon 4. HLA-DEL is also a nonfunctional gene because of the dual cytosine insertion in exon 4, with a reading frame shift generating a stop codon downstream. Parsimony analysis of the two pseudogenes with 31 other primate A locus coding regions resulted in a phylogenetic tree that segregated the two pseudogenes with the Gogo-A*0501, suggesting that HLA-COQ, HLA-DEL, and Gogo-A*0501 evolved from a common ancestral allele.
Assuntos
Alelos , Éxons/genética , Gorilla gorilla/genética , Antígenos de Histocompatibilidade Classe I/genética , Filogenia , Pseudogenes/genética , Sequência de Aminoácidos , Animais , Éxons/imunologia , Mutação da Fase de Leitura/genética , Mutação da Fase de Leitura/imunologia , Gorilla gorilla/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Dados de Sequência Molecular , Filipinas , Pseudogenes/imunologiaRESUMO
Twelve new B*15 alleles are described. All of the known B*15 alleles are divided into subgroups based on serologic assignments and/or nucleotide sequence polymorphisms. These groups might be used as a reference for DNA-based testing at an intermediate (i.e. "serologic") level of resolution.
Assuntos
Alelos , Antígenos HLA-B/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Éxons/imunologia , Conversão Gênica/imunologia , Antígenos HLA-B/química , Antígeno HLA-B15 , Humanos , Dados de Sequência Molecular , Família Multigênica/imunologiaRESUMO
This paper describes 29 novel HLA-B locus alleles identified during low-resolution typing. The majority of the novel alleles carry new patterns of previously known polymorphic motifs or codons. Three alleles carry alterations in the Bw4/Bw6 epitope. Five alleles carry novel substitutions.
Assuntos
Alelos , Antígenos HLA-B/genética , Família Multigênica/imunologia , Reações Cruzadas/genética , Antígenos HLA-B/imunologia , Humanos , Dados de Sequência MolecularRESUMO
This paper describes 9 novel HLA-B locus alleles. All of the alleles carry sequence motifs observed in other HLA-B alleles.