• polymorphism
  • The high level of HLA polymorphism is maintained in populations by balancing selection, specifically pathogen-driven selection with heterozygote advantage. (chori.org)
  • It is also noteworthy that extraordinary levels of variation in the 5'-upstream regulatory region of HLA-G exist, which may provide evidence for an association between a promoter-region single-nucleotide polymorphism and fetal loss rates. (nih.gov)
  • sequence
  • Specifically, marker DNA sequences which detect either directly or indirectly the identity of the codon encoding for the amino acid at position 57 of the DQ-beta protein sequence are disclosed as well as sequences from the DR-beta region. (google.com.au)
  • These two loci are highest sequence variation rate within human genome. (wikipedia.org)
  • In general, HLA DNA can be typed either by hybridizing labeled, sequence specific oligonucleotide probes to HLA loci amplified by the polymerase chain reaction (PCR), or by using PCR to amplify th e HLA DNA directly through differential primer extension. (bio-medicine.org)
  • One of the most commonly employed strategies in HLA DNA typing is to first amplify a given HLA locus, then hybridize it with a labeled, sequence specific oligonucleotide probe. (bio-medicine.org)
  • For those laboratories with access to Sequencers, it may be the most sensitive, specific and cost effective option to sequence certain HLA loci directly. (bio-medicine.org)
  • molecules
  • Within the DQ molecule both the alpha chain and the beta chain contain the polymorphisms specifying the peptide binding specificities, resulting in up to 4 different molecules. (wikipedia.org)
  • The HLA class I molecules also act as ligands for killer immunoglobulin receptors (KIR), which regulate the cytotoxic activity of natural killer (NK) cells. (chori.org)
  • HLA class II molecules are found on the surface of B cells, macrophages and other antigen presenting cells, where the alpha-beta heterodimer presents primarily exogenously derived peptides (bacteria and chemical toxins) to circulating CD4+ T cells. (chori.org)
  • NK cells are effector cells of the innate immune system that recognize the absence of HLA class I molecules from the surface of virally infected cells and target these cells for destruction through cytotoxicity and pro-inflammatory cytokine production1 (Figure 2). (chori.org)
  • HLA-DR molecules are upregulated in response to signalling. (wikipedia.org)
  • DM plays a central role in the peptide loading of MHC class II molecules by helping to release the CLIP (class II-associated invariant chain peptide) molecule from the peptide binding site. (antibodies-online.com)
  • Class I MHC molecules contain two separate polypeptide chains, the heavier (44-47 KDa) alpha chain and the lighter (12 KDa) beta chain. (periobasics.com)
  • polymorphisms
  • Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities. (wikipedia.org)
  • For many years HLA polymorphisms were typed by serological respons. (bio-medicine.org)
  • A clear understanding of the differences between HLA polymorphisms has provided ample insight into why and how foreign tissue is rejected by the host, and as such been a critical enabler of the field of transplantation. (bio-medicine.org)
  • The second HLA DNA typing technique is to use the PCR amplification reaction directly to detect HLA polymorphisms. (bio-medicine.org)
  • By constructing an array of PCR primers complementary to the range of HLA polymorphisms, it is possible to detect the HLA alleles directly by PCR. (bio-medicine.org)
  • imgt
  • http://www.ebi.ac.uk/ipd/imgt/hla/stats.html). (chori.org)
  • To aid in migration of data to the new nomenclature the WHO Nomenclature Committee for Factors of the HLA System has provided the IMGT/HLA Nomenclature Conversion Tool. (wikipedia.org)
  • New alleles that have never been assigned with a name prior to the April 2010 update are: Nomenclature of HLA Alleles The IMGT/HLA Database - HLA Dictionary. (wikipedia.org)
  • derived from IMGT/HLA Krasowska-Kwiecień A, Sancewicz-Pach K, Moczulska A (2006). (wikipedia.org)
  • Human
  • DNA sequences and corresponding amino acid sequences from the HLA class II beta region of the human genome that are associated with insulin-dependent diabetes mellitus (IDDM) and Pemphigus vulgaris (PV) have been identified. (google.com.au)
  • Also known as HLA-DXA or DAAP-381D23.2, it is part of the human leucocyte antigen system. (wikipedia.org)
  • Both loci are variable in the human population (see regional evolution). (wikipedia.org)
  • In the human population DQ is highly variable, the β subunit more so than the alpha chain. (wikipedia.org)
  • The complex of HLA-DR (Human Leukocyte Antigen - antigen D Related) and its ligand, a peptide of 9 amino acids in length or longer, constitutes a ligand for the T-cell receptor (TCR). (wikipedia.org)
  • The Past, Present and Future of HLA Typing ( The Human Leukocyte Antigen (HLA) regi. (bio-medicine.org)
  • The Human Leukocyte Antigen (HLA) region located on the short arm. (bio-medicine.org)
  • Today, a variety of techniques are applied for HLA tissue typing, providing an important tool to increase the success rate of human transplants. (bio-medicine.org)
  • The HLA complex is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species. (nih.gov)
  • This is the highest phenotype frequency observed for any DR or DQ phenotype in the human population by a wide margin. (wikipedia.org)
  • In the mouse bc1- or bc2- (which may be homologous to HLA-G1 and HLA-G2 of human) expressing RMA-S cells were protected from NK cell-mediated rejection in vivo. (nih.gov)
  • HLA class I histocompatibility antigen, A-2 alpha chain (365 aa, ~41 kDa) is encoded by the human HLA-A gene. (healthmatics.info)
  • isoform
  • Each combination of DPA1 allele gene product with each combination of DPB1 'gene' product can potentially recombine to produce one isoform. (wikipedia.org)
  • Much of the isoform variation in DQ is within these 'functional' regions. (wikipedia.org)
  • DQ2.2 is shorthand for the DQ α2β2 heterodimeric isoform. (wikipedia.org)
  • The soluble HLA-G1 isoform downregulates both CD8+ 21 and CD4+ T cell reactivity. (nih.gov)
  • linkage
  • This linkage analysis is particularly useful when HLA typing for an individual with limited family HLA typing available. (google.fr)
  • It is also closely linked to HLA-DQ and this linkage often makes it difficult to resolve the more causative factor in disease. (wikipedia.org)
  • With DR3 this DQ2 has the second strongest linkage to Type 1 diabetes, and when paired with HLA-DQ8 is the most abundant phenotype found in late onset, "Type1-Type2" diabetes mellitus type 1. (wikipedia.org)
  • 0202
  • For example, the allele discovered after HLA-DPB1*9901 was assigned as DPB1*0102, the subsequent allele was named DPB1*0202, then *0302 and so on. (wikipedia.org)
  • In the 2010 HLA nomenclature update, all DPB1 alleles, except DPB1*0202 and *0402, discovered after DPB1*9901 were reassigned with new numbers. (wikipedia.org)
  • Super B8
  • In the Super B8 complex DP locus is more frequently substituted, either as a result of its distance from other loci, or because it was not as actively selected in the evolution of Super B8. (wikipedia.org)
  • humans
  • The HLA-C locus has been found only in humans, gorilla and chimpanzees but not in monkeys 17 . (tripod.com)
  • 18 In humans, natural killer cells are inhibited by HLA-G via NKAT3, which contributes to the survival of the fetal semi-allograft in the mother during pregnancy. (nih.gov)
  • immune
  • Dr. Trachtenberg also collaborates on studies of HLA and KIR in stem cell transplantation, a unique environment combining individual donor and recipient immune systems. (chori.org)
  • Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes. (healthmatics.info)
  • Serological
  • Serological studies of DQ recognized that antibodies to DQ bind primarily to the β-chain. (wikipedia.org)
  • However, the advent of recombinant DNA technology, which paved the way to identifying genetic differences among the HLA loci directly, has led many laboratories to abandon classic serological typing methods. (bio-medicine.org)
  • peptides
  • HLA-DM mediates a noncooperative release of prebound influenza virus hemagglutinin (show HA ELISA Kits ) peptides from wild-type HLA- DR1 (show DR1 ELISA Kits ) by destabilizing the beta81 hydrogen (H-)bond, since a similar phenomenon is observed when this H-bond is absent. (antibodies-online.com)
  • antibodies
  • Antibodies raised against DQ tend to recognize these functional regions, in most cases the β-subunit. (wikipedia.org)
  • Nomenclature
  • The first standardized naming system was established in 1968 by the WHO Nomenclature Committee for Factors of the HLA System. (wikipedia.org)
  • This name assignment has been the most confusing system within the HLA nomenclature. (wikipedia.org)
  • By looking at the change of disease association with improved testing we can see how HLA nomenclature has evolved over time. (wikipedia.org)