摘要:

B*2704 and B*2706 are closely related HLA–B27 subtypes of which the former but not the latter is associated to ankylosing spondylitis. Their peptide specificity relative to other disease–associated subtypes was analyzed by testing binding of self–peptides naturally presented by B*2705 or B*2702, and synthetic analogs, to B*2704, B*2706, and site–specific mutants mimicking their changes. Peptides with basic, aliphatic or aromatic C–terminal residues bound to B*2705 with similar affinity. In B*2704 C–terminal aliphatic/aromatic residues were preferred. B*2706 discriminated drastically between polar and nonpolar C–terminal residues, showing strong preference for Leu and Phe, and less than B*2704 for basic and Tyr residues. Loss of single acidic charges (D>S77, D>Y116) increased preference for C–terminal Leu and Phe, but allowed efficient binding of peptides with basic residues or Tyr. Their gain (V>E152, H>D114) maintained wide C–terminal specificity, but severely impaired binding, presumably by disrupting interactions with internal peptide residues. This was compensated by Y116 in the double Dl 14Y116 mutant. The specificity of B*2704 and B*2706 was explained only partially by the separate effects of single mutations, indicating that novel properties arise from concomitant changes at various positions. For instance, specificity of B*2706 for nonpolar C‐terminal residues required simultaneous removal of Asp77and Asp116. B*2706 differed from B*2705, B*2702, and B*2704 in its lower suitability for C‐terminal Tyr, suggesting that this feature might be relevant for HLA–B27 association

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02664.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The expression of CD95 antigen was examined on adult and cord blood lymphocytes using a highly sensitive immunofluorescence/flow cytometric procedure. CD95 was expressed by the majority of circulating blood T cells in adults, and by a smaller proportion of CD4+ and CD8+ T cells in cord blood. The majority of circulating B cells did not react with seven CD95 antibodies, but three antibodies did stain B cells. In tonsil sections, CD95 was expressed throughout the tissue, but germinal centres showed generally stronger staining than the surrounding follicular mantle and interfollicular areas. This was confirmed by flow cytometry, which showed expression preferentially on B cells with a germinal centre phenotype. Because different antibodies stained different proportions of B cells, CD95 epitopes were examined by inhibition, additive binding and protease susceptibility studies using a panel of ten CD95 antibodies. B cells apparently reacting selectively with CD95 antibodies were sorted and CD95 mRNA was reverse transcribed to cDNA and analyzed, in order to confirm the presence of CD95 in cells which reacted selectively and to explore the possible existence of CD95 isoforms. The major cDNA band was identical in the two populations. Inhibition of N‐glycosylation suggested that the epitopes detected differentially could not be accounted for by differential N‐glycosylat

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02665.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

A murine monoclonal antibody (mAb) S‐Endo 1 has been produced to detect circulating endothelial cells detached from blood vessels in pathological conditions. We have demonstrated that the associated‐antigen (S‐Endo 1 Ag) was highly expressed on human vascular structure irrespective of tissue origin or vessel caliber. Its expression was not restricted to endothelium, since it was also detected at low level on smooth muscle cells, stroma cells and follicular dendritic cells. But its absence on hematopoietic cells made S‐Endo 1 a helpful reagent to specifically discriminate endothelium from hematopoietic tissues. Biochemical characterization showed that S‐Endo 1 recognizes a monomelic structure of ˜ 118 kDa on cultured endothelial cells. S‐Endo 1 was submitted to the 5th International Workshop (Boston, 1993) and did not cluster in any of the old or new endothelial clusters discussed at the conference, indicating its unique reactivity. Together with the data presented in this paper, this suggested that S‐Endo 1 defines a previously undescribed endoth

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02666.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The aim of this study was to compare the genetic susceptibility linked to the HLA Class II region genes of the Major Histocompatibility Complex in isolated insulin‐dependent diabetes mellitus (la‐IDDM) and insulin‐dependent diabetes mellitus associated with another autoimmune endocrinopathy (lb‐IDDM). HLA genes DRB1, DQA1 and DQB1 were studied at the genomic level, as well as genes TAP1 and TAP2. One hundred and seventy‐nine la‐IDDM diabetic patients were compared with 83 lb‐IDDM patients. While it appeared that common genetic traits characterize diabetes regardless of the subtype (la or lb), certain features differentiate the two forms of IDDM. Extending the analysis of risk haplotypes DRB1*03 and DRB1*04 to TAP genes elicited a difference between la‐IDDM and lb‐IDDM patients. Haplo‐type DRB1*03 was thus characterized in la‐IDDM patients by a lower frequency of alleles TAP1‐B (13.5%) and TAP2‐B (16.2%), not found in lb‐IDDM patients (33.3% for each allele). Likewise, haplotype DRB1*04 is characterized in lb‐IDDM patients by a lower frequency of alleles TAP1‐C (4.0%) and TAP2‐B (8.0%) than in la‐IDDM patients (22.2% and 25.9%, respectively). In total, this study showed that extending the characterization of HLA Class II haplotypes to TAP genes discriminates between the forms of diabetes restricted to a specific pancreatic affection and those reflecting a wider autoimmun

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02667.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The dog is an important model for studying organ transplantation. In order to develop a DNA‐based typing system, a genomic analysis of the canine DR region of the MHC was undertaken. Southern analysis suggests the presence of two DRB genes in most dogs and all have one DRA gene. One dog out of 200 examined contains only one DRB gene. The DRA gene was mapped in one lambda phage clone. One DRB gene (DRBB1) was localized to two overlapping phage clones. Another DRB gene (DRBB2) was localized to two overlapping phage clones. Sequence analysis of the two DRB genes suggests that one gene is intact (DRBB1) and one gene is a pseudogene (DRBB2) because it lacks a splice acceptor signal for exon 3 and lacks exons 2 and exon 4. Intron 1 and 2 sequence data from DRBB1 allow amplification of the polymorphic exon 2 which, in turn, can serve as a basis for developing a typing system for DR

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02668.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The polymorphism of the canine major histocompatibility complex class II DRB gene, DRBB1, was analyzed. Exon 2 that encodes the polymorphic 81 domain was amplified by the polymerase chain reaction (PCR). The PCR product from 250 dogs was cloned and sequenced. Eighteen alleles were identified. Most of the variation in amino acid composition occurred at positions in the peptide binding site. Inheritance of these sequences showed Mendelian segregation with one or two alleles per dog. Cluster analysis of the nucleotide and predicted amino acid sequences subdivided the canine DRBB1 alleles into three major allelic groups. The number of nonsynonymous changes was higher than the number of synonymous changes in the putative antigen recognition sites indicative of positive selection. The data generated can serve as a basis for developing a typing assay for the canine DRBB1 gene.

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02669.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

We analyzed the HLA‐A, ‐B, ‐C, ‐DR and ‐DQ phenotypes of 2,440 healthy, unrelated, Dutch Caucasoid blood donors and of 20, 814 Dutch blood donors who were registered as volunteer bone marrow or platelet donors. Phenotype and gene frequencies, Hardy‐Weinberg equilibrium fit and homozygosity were calculated as well as 2‐ and 3‐locus haplotype frequencies, deltas, relative deltas and significance levels of the deltas. The population appears to be in Hardy‐Weinberg equilibrium. Many haplotypes are in strong positive linkage disequilibrium. A phylogenetic tree, based on the HLA‐A, ‐B and ‐DR gene frequencies of blood donors in different Dutch regions, reflects the limited but manifest heterogeneity of the Dutch population. Additionally we introduce a stepwise test for Hardy‐Weinberg equilibrium and discuss the applicability of this test and of the single test for Hardy‐Weinberg equilibrium for tissue typing quality control and for selection of split antigens prior to gene and h

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02670.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

An unexpected probe reaction pattern was observed in two samples during HLA‐DR typing by PCR‐Sequence Specific Oligonucleotide Probes. In order to confirm the unusual typings, samples were analyzed by PCR‐Sequence Specific Primers, cloning, and nucleotide sequencing of the second exon of the HLA‐DRB‐genes. The confirmed DR, DQ phenotype for one sample was DRB1*0701, DRB4*01, DRB5*0101, DRB6*0201, DQB*0602, DQB1*0202. The phenotype of other sample was DRB1*1602, DRB1*1302, DRB3*0301, DRB6*0101, DQB1*0501, DQB1*0502. The first sample has the novel combination of DRB1*0701 with DRB5*0101 and DRB6*0201. The second sample has either DRB6*0101 together with DRB 1*1602 in absence of any DRB5 allele or DRB6*0101 together with DRB1*1302, DRB 3*0301. We postulate that the most likely haplotype in sample #1 is DRB1*0701, DRB5*0101, DRB1*0602 which could have arisen from gene conversion. The most likely haplotype in sample #2, DRB 1*1602, DRB6*0101, DQB1*0502 would have arisen from an homologous recombinat

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02671.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

We have discovered a new HLA‐DQB 1 allele in a Japanese family, MAT. In the family the new allele segregates in three generations and demonstrates the positive association with DRB 1*0901. We observed a novel RFLP pattern in the course of examining the modified PCR‐RFLP method for HLA‐DQB 1 genotyping. The PCR‐SSOP analysis also showed a new hybridized pattern. Sequence analysis of the allele indicates that it was generated by a gene conversion‐like event between the HLADQB 1*03032 and one of DQB 1*04 contemporary alleles. This new allelic product did not react with all of allosera and monoclonal antibodies against DQ1, DQ2, DQ3, DQ4 and DQ7. The HLA molecule encoded by the allele is not defined by serology. This new allele was officially recognized and named DQB 1*0306 by the WHO Nomenclature Committee in Nove

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02672.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Characterization of 50 local anti‐HLA‐A9 (A23 and/or A24) sera against the HLA‐A2403 antigen allowed the retrospective assignment of A2403 and the verification of A23 and A24 specificities in a panel of 9196 volunteer bone marrow donors. The six A2403 positive subjects identified were confirmed by PCR using four sequence‐specific primer mixtures. Population analysis showed the distribution and HLA‐A/B linkage disequilibrium of HLA‐A23 and A24 to be typical of a Northern European Caucasoid population. HLA‐A2403 has a phenotype frequency of 0.00065 (gene frequency ‐ 0.00033) and is in linkage disequilibrium with HLA‐B63

ISSN:0001-2815    

DOI:10.1111/j.1399-0039.1996.tb02673.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY