Search results for "HLA-DR"
showing 6 items of 96 documents
Importance of HLA-DR+ and CD1a+ Epidermal Cells for Cytokine Production in Psoriasis
1995
Psoriasis is an inflammatory skin disease characterised by marked hyperproliferation of keratinocytes in association with vascular expansion, leukocyte infiltration and lymphocyte activation1. Cytokines are thought to play a pivotal role in the pathogenesis. It is speculated that a dysregulation of the cytokine network involving tumor-necrosis-factor-a (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) might be the basic mechanism of the psoriatic inflammatory response2. TNF-α is the prototype of a proinflammatory peptide exerting immunomodulatory effects. IL-6 is a multifunctional cytokine with a broad range of biological functions in both acute and chronic inflammatory reactions. IL-8…
Characterization of HLA-DR- and TCR-binding residues of an immunodominant and genetically permissive peptide of the 16-kDa protein of Mycobacterium t…
2004
The 16-kDa protein of Mycobacterium tuberculosis represents an important antigenic target during bacillary latency and, consequently, should be considered as candidate subunit vaccine component. In this study, we have used CD4 T cell clones that recognize the peptide p91-110, an immunodominant and genetically permissive epitope, in the context of five different HLA-DR molecules and truncated and substituted variants of this peptide, to identify the minimal binding sequence (HLA-DR-binding core) and the minimal stimulatory sequence (TCR-binding core), as well as the residues that contact HLA-DR molecules and the TCR. We have found a common 9-mer sequence, spanning amino acids 93-101, as the …
Mixed Epidermal Cell Lymphocyte Reaction: HLA-DR+ Cells Exhibit a Greater Immunostimulatory Activity than CD1a+ Cells
1995
Induction and expression of immunity depends upon processing and presentation of antigens to T-cells by bone marrow derived HLA-DR+ antigen presenting cells (APC). In the induction of immunity to cutaneous antigens, the initial stages of this process begin within the skin itself, and both epidermis and dermis contain bone-marrow derived cells that have the capability of processing and presenting antigens. In normal epidermis, HLA-DR expression is believed to be confined to Langerhans cells with Birbeck granules and indeterminate cells without Birbeck granules. In diseased skin, particularly the inflammatory dermatoses, HLA-DR is commonly expressed by keratinocytes and has been related to th…
Analysis of HLA-DRB1,DQA1,DQB1 haplotypes in Sardinian centenarians
2008
Some genetic determinants of longevity might reside in those polymorphisms for the immune system genes that regulate immune responses. Many longevity association studies focused their attention on HLA (the human MHC) polymorphisms, but discordant results have been obtained. Sardinians are a relatively isolate population and represent a suitable population for association studies. Some HLA-DR and DQ alleles form very stable haplotypes with a strong linkage disequilibrium. In a previous study on Sardinian centenarians we have suggested that HLA-DRB1 *15 allele might be marginally associated to longevity. HLA-DR,DQ haplotypes are in strong linkage disequilibrium and well conserved playing a ro…
Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.
1993
The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …
Sequence analysis of the DRB1 promoter reveals limited polymorphism with no influence on gene expression.
2001
HLA-class II promoters contain a set of conserved regulatory regions necessary for constitutive and induced gene expression. For the HLA-DQB as well as for the DRB1 promoter sequence, polymorphisms with influence on gene expression have been reported. In contrast to these data we could show that there is very limited allele-specific polymorphism among the HLA-DRB1 promoter alleles. In a long range PCR we amplified a DNA sequence containing the promoter and the second exon of the DRB1 gene in one fragment. Nested PCR products of this PCR fragment for the promoter and for the second exon were analysed by DNA sequencing to allow the linkage of a promoter to its DR allele. Most investigated DRB…