UnusualHLA-DR/DQ haplotypes: two different breakpoints in two differentDR2-DQw3 haplotypes

Andreas, A.; Chandanayingyong, D.; Attatippaholkun, Watcharee; Sirikong, Monchan; Klaythong, R.; Keller, E.; Albert, E. D.

doi:10.1007/bf02421546

Cited by 12 publications

(2 citation statements)

References 14 publications

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“…As in the mouse, the location of recombination events varies among haplotypes (Gregersen et al 1988). Evidence from several studies suggests a significant rate of recombination between the expressed DQA1 and DQB1 genes (Andreas et al 1989;Santamaria et al 1992;Satyanarayana and Strominger 1992). In addition, recombination hotspots have not been described for the DR region.…”

Section: Seb (Ug)mentioning

confidence: 99%

The minimal polymorphism of class II E? chains is not due to the functional neutrality of mutations

et al. 1994

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Given the extensive allelic amino acid sequence polymorphism present in the first domain of A alpha, A beta, and E beta chains and its profound effects on class II function, the minimal polymorphism in the mouse E alpha chain (and in its human homologue DR alpha) is paradox. Two possible explanations for the lack of polymorphism in E alpha are: (1) the E alpha chain plays such a uniquely critical structural/functional role in antigen presentation, T-cell activation, repertoire selection, and/or pairing with E beta or other proteins for expression that it cannot vary, and mutations are selected against; (2) the E alpha chain plays a less significant role than the outer domains of other major histocompatibility complex (MHC) proteins in determining the interactions with processed peptides or with T-cell receptor (TCR), so there is no selective pressure to maintain new mutations. To explore this question we compared the ability of transfectants expressing wild type (wt) E alpha E beta d and mutant E alpha wt E beta d proteins to present peptides and bacterial superantigens to T-cell hybridomas. Mutations at the E alpha amino acid positions 31, 52, and 65&66, to residues that represent allelic alternatives in A alpha chains, significantly reduced activation of peptide-specific T hybridomas, and mutations at 71 sometimes enhanced T-cell stimulation. None of the E alpha mutations reduced, and some enhanced, superantigen stimulation of T-cell hybridomas. These results argue against the hypothesis that E alpha chains are minimally polymorphic because mutations in E alpha are functionally neutral.

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Section: Seb (Ug)mentioning

confidence: 99%

The minimal polymorphism of class II E? chains is not due to the functional neutrality of mutations

et al. 1994

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“…The HLA class I1 DRB and DQB alleles are determined by Taq I and EcoRI RFLP analysis using a typing system established in our laboratory based on the results of our reference panel of more than 200 unrelated individuals and 40 families, and of 100 workshop cell lines (Andreas et al, 1989;Dupont, 1989). Table 1 shows which genes were informative in deducing the paternal and maternal haplotypes of the fetus and our diagnostic conclusions.…”

Section: Methodsmentioning

confidence: 99%

Prenatal diagnosis of 21‐hydroxylase deficiency by rflp analysis of the 21‐hydroxylase, complement C4, and HLA class II genes

et al. 1991

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In 19 pregnancies at risk for 21-hydroxylase deficiency (210HD) in 18 families with at lea one affected child, prenatal diagnosis was performed by RFLP analysis using the enzymc Taq 1 and EcoRI and the DNA probes specific for the 210H genes, the closely linke complement C4 genes and the highly polymorphic HLA class I1 genes DRB, DQB, and DPI For fetal DNA analysis either chorionic villi or cultivated amniotic cells were used. In all 1 cases, a clear prenatal diagnosis was possible either with the 210H probe alone or in mo cases, by combining the results of the different closely linked loci. KEY WORDS Prenatal diagnosis 21-Hydroxylase deficiency DNA analysis

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Hypervariability of intronic simple (gt)n(ga)m repeats in HLA-DRB genes

et al. 1990

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We have investigated the extent of DNA variability in intronic simple (gt)n(ga)m repeat sequences and correlated this to sequence polymorphisms in the flanking exon 2 of HLA-DRB genes. The polymerase chain reaction (PCR) was used to amplify a DNA fragment containing exon 2 and the repeat region of intron 2. The PCR products were separated on sequencing gels in order to demonstrate length hypervariability of the (gt)n(ga)m repeats. In a parallel experiment, the PCR products were cloned and sequenced (each exon 2 plus adjacent simple repeats) to characterize the simple repeats in relation to the HLA-DRB sequences. In a panel of 25 DRB1, DRB4, and DRB5 alleles new sequences were not detected. Restriction fragment length polymorphism (RFLP) subtyping of serologically defined haplotypes corresponds to translated DNA sequences in 85% of the cases, the exceptions involving unusual DR/DQ combinations. Many identical DRB1 alleles can be distinguished on the basis of their adjacent simple repeats. We found group-specific organization of the repeats: the DRw52 supergroup repeats differ from those of DRB1*0101, DRB4*0101, and DRB5*0101 alleles and from those of pseudogenes. Finally, we amplified baboon DNA and found a DRB allele with extensive similarity to DRB1 sequences of the DRw52 supergroup. The simple repeat of the baboon gene, however, resembles that of human pseudogenes. In addition to further subtyping, the parallel study of polymorphic protein and hypervariable DNA alleles may allow conclusions to be drawn on the relationships between the DRB genes and perhaps also on the theory of trans-species evolution.

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UnusualHLA-DR/DQ haplotypes: two different breakpoints in two differentDR2-DQw3 haplotypes

Cited by 12 publications

References 14 publications

The minimal polymorphism of class II E? chains is not due to the functional neutrality of mutations

The minimal polymorphism of class II E? chains is not due to the functional neutrality of mutations

Prenatal diagnosis of 21‐hydroxylase deficiency by rflp analysis of the 21‐hydroxylase, complement C4, and HLA class II genes

Hypervariability of intronic simple (gt)n(ga)m repeats in HLA-DRB genes

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