HLA-B7

Last updated
HLA-B.png
major histocompatibility complex (human), class I, B7
AllelesB*0702, *0703, *0704, *0705
Structure (See HLA-B)
Alleles (See Serotyping)
Locus chr.6 6p21.31

HLA-B7 (B7) is an HLA-B serotype. The serotype identifies the more common HLA-B*07 gene products. [1] (For terminology help see: HLA-serotype tutorial) B7, previously HL-A7, was one of the first 'HL-A' antigens recognized, largely because of the frequency of B*0702 in Northern and Western Europe and the United States. B7 is found in two major haplotypes in Europe, where it reaches peak frequency in Ireland. One haplotype A3-B7-DR15-DQ1 can be found over a vast region and is in apparent selective disequilibrium. B7 is a risk factor for cervical cancer, sarcoidosis, and early-onset spondylarthropathies.[ citation needed ]

Contents

Serology

B7 serotype recognition of Some HLA B*07 allele-group gene products [2]
B*07B7Sample
allele %size (N)
*0702 9810841
*0703 9315
*0704 8944
*0705 9542
*0706 9623
*0707 9213
*0709 789
Alleles link-out to IMGT/HLA Databease at EBI

Alleles

HLA B*0702 frequencies
freq
ref.Population(%)
[3] Ireland South17.6
[3] Ireland Northern17.3
[3] Australia New South Wales12.0
[3] Croatia9.7
[3] Azores S. Maria & Miguel9.0
[3] Cameroon Beti8.6
[3] Saudi Arabia Guraiat and Hail8.3
[3] Azores Central Islands8.0
[3] France South East7.2
[3] Cameroon Bamileke7.1
[3] Portugal Centre7.0
[3] Italy North pop 16.7
[3] Japan Central6.5
[3] Czech Republic6.1
[3] Uganda Kampala5.9
[3] Mali Bandiagara5.8
[3] Senegal Niokholo Mandenka5.8
[3] India Mumbai Marathas4.9
[3] Zambia Lusaka4.6
[3] Zimbabwe Harare Shona4.6
[3] South African Natal Zulu4.5
[3] Romanian3.7
[3] South Korea (3)3.5
[3] Shijiazhuang Tianjian Han, China3.4
[3] India North Delhi3.3
[3] Kenya Luo2.5
[3] China Guangzhou Han2.4
[3] Mexico Chihuahua Tarahumara2.3
[3] Sudanese2.3
[3] Singapore Javanese Indonesians2.0
[3] Spain Eastern Andalusia Gipsy2.0
[3] New Caledonia1.9
[3] Oman1.7
[3] USA Alaska Yupik Natives1.6
[3] China Beijing1.5
[3] Tunisia1.5
[3] Argentina Toba Rosario1.2
[3] Singapore Chinese Han1.2
[3] USA Arizona Pima1.1
[3] American Samoa1.0
[3] Japan Ainu Hokkaido1.0
[3] Kenya Nandi1.0
[3] Portugal South1.0
[3] Singapore Riau Malay1.0
[3] Singapore Thai1.0

In disease

Cervical cancer

HLA-B7 along with HLA-DQ8 increased risk for cervical cancer in Costa Rican [4] and South Asian women [5]

Sarcoidosis

A weak relationship between HLA-B7 and sarcoidosis has been known for 30+ years, [6] yet has not consistently been reproducible in all studies however. A common serologically defined haplotype in Europeans is HLA A3-Cw7-B7-DR15-DQ6.2 which is composed of alleles A*0301:Cw*0701:B*0702:DRB1*1501:DQA1*0102:DQB1*0602. In persistent sarcoidosis this haplotype appears elevated, further study eliminated risk contributed by A3-Cw7 and DQ6.2 indicating B7-DR15 haplotype contains risk of disease (OR = 2.5). Corresponding region of chromosome 6 contains nearly one million nucleotides thus these genes, or another closely linked gene could be involved in such massing of inflammatory granulomata. [7]

Juvenile Spondylarthropathies

In Croatian children, two HLA-B27 alleles were found associated with disease, B*2702, B*2705. [8] The study showed also B*0702 in cooperation with B*27, the HLA-B*07/B*27 combination with D6S273-134 genomic marker allele and was found not to be the result of linkage disequilibrium. B*2705 was found to be dominant allele associated.

Haemochromatosis

The HFE gene responsible for haemochromatosis is distal on chromosome 6 from HLA-A and more so from HLA-B, the distance suffices (3 million nucleotides) to allow equilibration of the loci. Nonetheless, a linkage has been found between A3-B7 haplotype and haemochromatosis. The region is almost 1.4 million nucleotides in length and contains many other genes that could be involved. A more recent study looked at a number of linked gene-alleles and found I82-2:D6S265-1:HLA-A3:D6S128-2:HLA-F1:D6S105-8 was constantly associated while B7 appeared beyond the haplotype linked to disease. [9]

Covid-19

In october 2021, a team of researcher from Centre hospitalier universitaire Sainte-Justine in Montreal, Canada, announced the discovery of HLA-B7 genetic marker as a potential cause for severe form of covid-19. While they noted that more work will be necessary to confirm this discovery, they found that individuals carrying the HLA-B7 genetic marker, which represents 35% of the population worldwide, are more likely to have a less effective immune response to covid-19. [10] [11]

Related Research Articles

<span class="mw-page-title-main">Human leukocyte antigen</span> Genes on human chromosome 6

The human leukocyte antigen (HLA) system or complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals.

HLA DR3-DQ2 is double serotype that specifically recognizes cells from individuals who carry a multigene HLA DR, DQ haplotype. Certain HLA DR and DQ genes have known involvement in autoimmune diseases. DR3-DQ2, a multigene haplotype, stands out in prominence because it is a factor in several prominent diseases, namely coeliac disease and juvenile diabetes. In coeliac disease, the DR3-DQ2 haplotype is associated with highest risk for disease in first degree relatives, highest risk is conferred by DQA1*0501:DQB1*0201 homozygotes and semihomozygotes of DQ2, and represents the overwhelming majority of risk. HLA DR3-DQ2 encodes DQ2.5cis isoform of HLA-DQ, this isoform is described frequently as 'the DQ2 isoform', but in actuality there are two major DQ2 isoform. The DQ2.5 isoform, however, is many times more frequently associated with autoimmune disease, and as a result to contribution of DQ2.2 is often ignored.

<span class="mw-page-title-main">HLA-DQ4</span>

HLA-DQ4 (DQ4) is a serotype subgroup within HLA-DQ(DQ) serotypes. The serotype is determined by the antibody recognition of β4 subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ4 are encoded by the HLA-DQB1*04 allele group. This group currently contains 2 common alleles, DQB1*0401 and DQB1*0402. HLA-DQ4 and HLA-DQB1*04 are almost synonymous in meaning. DQ4 β-chains combine with α-chains, encoded by genetically linked HLA-DQA1 alleles, to form the cis-haplotype isoforms. These isoforms, nicknamed DQ4.3 and DQ4.4, are also encoded by the DQA1*0303 and DQA1*0401 genes, respectively.

<span class="mw-page-title-main">HLA-DQ5</span>

HLA-DQ5 (DQ5) is a human leukocyte antigen serotype subgroup within HLA-DQ(DQ) serotypes. The serotype is determined by the antibody recognition of β5.x subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ5 are encoded by the HLA-DQB1*05 allele group. This group currently contains 4 common alleles, DQB1*0501, *0502, *0503, and *0504. HLA-DQ5 and HLA-DQB1*05 are almost synonymous in meaning. DQ5 β-chains combine with α-chains, encoded by genetically linked HLA-DQA1 alleles, to form the cis-haplotype isoforms. These isoforms, are all HLA-DQ1 encoded by the DQA1*01 allele group.

<span class="mw-page-title-main">HLA-DQ6</span>

HLA-DQ6 (DQ6) is a human leukocyte antigen serotype within HLA-DQ (DQ) serotype group. The serotype is determined by the antibody recognition of β6 subset of DQ β-chains. The β-chain of DQ isoforms are encoded by HLA-DQB1 locus and DQ6 are encoded by the HLA-DQB1*06 allele group. This group currently contains many common alleles, DQB1*0602 is the most common. HLA-DQ6 and DQB1*06 are almost synonymous in meaning. DQ6 β-chains combine with α-chains, encoded by genetically linked HLA-DQA1 alleles, to form the cis-haplotype isoforms. For DQ6, however, cis-isoform pairing only occurs with DQ1 α-chains. There are many haplotypes of DQ6.

<span class="mw-page-title-main">HLA-DQ1</span> Serotype that covers a broad range of HLA-DQ haplotypes.

HLA-DQ1 is a serotype that covers a broad range of HLA-DQ haplotypes. Historically it was identified as a DR-like alpha chain called DC1; later, it was among 3 types DQw1, DQw2 and DQw3. Of these three serotyping specificities only DQw1 recognized DQ alpha chain. The serotype is positive in individuals who bear the DQA1*01 alleles. The most frequently found within this group are: DQA1*0101, *0102, *0103, and *0104. In the illustration on the right, DQ1 serotyping antibodies recognizes the DQ α (magenta), where antibodies to DQA1* gene products bind variable regions close to the peptide binding pocket.

<span class="mw-page-title-main">HLA-DR17</span>

HLA-DR17 (DR17) is an HLA-DR serotype that recognizes the DRB1*0301 and *0304 gene products. DR17 is found at high frequency in Western Europe. DR17 is part of the broader antigen group HLA-DR3 and is very similar to the group HLA-DR18.

<span class="mw-page-title-main">HLA-DR16</span>

HLA-DR16(DR16) is a HLA-DR serotype that recognizes the DRB1*1601, *1602 and *1604 gene products. DR16 is found in the Mediterranean at modest frequencies. DR16 is part of the older HLA-DR2 serotype group which also contains the similar HLA-DR15 antigens.

<span class="mw-page-title-main">HLA-DR15</span>

HLA-DR15 (DR15) is a HLA-DR serotype that recognizes the DRB1*1501 to *1505 and *1507 gene products. DR15 is found at high levels from Ireland to Central Asia. DR15 is part of the older HLA-DR2 serotype group which also contains the similar HLA-DR16 antigens.

<span class="mw-page-title-main">HLA-DR11</span>

HLA-DR11 (DR11) is a HLA-DR serotype that recognizes the DRB1*1101 to *1110. DR11 serotype is a split antigen of the older HLA-DR5 serotype group which also contains the similar HLA-DR12 antigens.

<span class="mw-page-title-main">HLA-DR7</span>

HLA-DR7 (DR7) is a HLA-DR serotype that recognizes the DRB1*0701 to *0705 gene products.

<span class="mw-page-title-main">HLA-A1</span> Human leukocyte antigen serotype

HLA-A1 (A1) is a human leukocyte antigen serotype within HLA-A "A" serotype group. The serotype is determined by the antibody recognition of α1 subset of HLA-A α-chains. For A1, the alpha "A" chain are encoded by the HLA-A*01 allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*01:01. A1 and A*01 are almost synonymous in meaning. A1 is more common in Europe than elsewhere, it is part of a long haplotype that appears to have been frequent in the ancient peoples of Northwestern Europe. A1 is a frequent component of the AH8.1 haplotype. A1 serotype positivity is roughly linked to a large number of inflammatory diseases and conditions believed to have immune system involvement. Because of its linkage within the AH8.1 haplotype many studies showed association with A1 or A1,B8 only later to show the association drift toward the class II region gene alleles, DR3 and DQ2.5. While it is not clear what role A1 has in infectious disease, some linkage with infection rates in HIV remain associated within the A1 region of the haplotype.

<span class="mw-page-title-main">HLA-A*02</span>

HLA-A*02 (A*02) is a human leukocyte antigen serotype within the HLA-A serotype group. The serotype is determined by the antibody recognition of the α2 domain of the HLA-A α-chain. For A*02, the α chain is encoded by the HLA-A*02 gene and the β chain is encoded by the B2M locus. In 2010 the World Health Organization Naming Committee for Factors of the HLA System revised the nomenclature for HLAs. Before this revision, HLA-A*02 was also referred to as HLA-A2, HLA-A02, and HLA-A*2.

<span class="mw-page-title-main">HLA-A3</span>

HLA-A3 (A3) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α3 subset of HLA-A α-chains. For A3, the alpha, "A", chain are encoded by the HLA-A*03 allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*03:01. A3 and A*03 are almost synonymous in meaning. A3 is more common in Europe, it is part of the longest known multigene haplotype, A3~B7~DR15~DQ6.

<span class="mw-page-title-main">HLA-A69</span>

HLA-A69 (A69) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α69 subset of HLA-A α-chains. For A69, the alpha "A" chain are encoded by the HLA-A*69 allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*6901. A69 and A*69 are almost synonymous in meaning. A69 is a split antigen of the broad antigen serotype A28. A69 is a sister serotype of A68.

<span class="mw-page-title-main">HLA-A33</span>

HLA-A33 (A33) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α33 subset of HLA-A α-chains. For A33, the alpha "A" chain are encoded by the HLA-A*33 allele group and the β-chain are encoded by B2M locus. A33 and A*33 are almost synonymous in meaning. A33 is a split antigen of the broad antigen serotype A19. A33 is a sister serotype of A29, A30, A31, A32, and A74.

HLA A1-B8-DR3-DQ2 haplotype is a multigene haplotype that covers a majority of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles; common multigene haplotypes are generally the result of descent by common ancestry. Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.

HLA A1-B8 is a multigene haplotype that covers the MHC Class I region of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles; common multigene haplotypes are generally the result of identity by descent from a common ancestor. Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.

HLA-Cw7 (Cw7) is a human leukocyte antigen serotype within HLA-C serotype group. Cw7 is determined by the antibody recognition of α7 subset of HLA-Cw α-chains. For the serotype Cw7, the alpha chain are encoded by the HLA-Cw*07 allele group and the β-chain are encoded by B2M locus. Cw7 and Cw*07 are almost synonymous in meaning. Cw7 is more common in West Africa to Ireland. Cw7 in Europe is part of the AH8.1 and HLA B7-DR15-DQ6 haplotypes. The class I region of these supertype is HLA A1-B8 haplotype, HLA A3-B7, HLA-A2-B7 and HLA A24-B7.

HLA B7-DR15-DQ6 is a multigene haplotype that covers a majority of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles, common multigene haplotypes are generally the result of descent by common ancestry. Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.

References

  1. ↑ Marsh, S. G.; Albert, E. D.; Bodmer, W. F.; Bontrop, R. E.; Dupont, B.; Erlich, H. A.; Fernández-Viña, M.; Geraghty, D. E.; Holdsworth, R.; Hurley, C. K.; Lau, M.; Lee, K. W.; Mach, B.; Maiers, M.; Mayr, W. R.; Müller, C. R.; Parham, P.; Petersdorf, E. W.; Sasazuki, T.; Strominger, J. L.; Svejgaard, A.; Terasaki, P. I.; Tiercy, J. M.; Trowsdale, J. (2010). "Nomenclature for factors of the HLA system, 2010". Tissue Antigens. 75 (4): 291–455. doi:10.1111/j.1399-0039.2010.01466.x. PMC   2848993 . PMID   20356336.
  2. ↑ derived from IMGT/HLA
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Middleton D, Menchaca L, Rood H, Komerofsky R (2003). "New allele frequency database". Tissue Antigens. 61 (5): 403–7. doi: 10.1034/j.1399-0039.2003.00062.x . PMID   12753660.
  4. ↑ Wang SS, Wheeler CM, Hildesheim A, et al. (November 2001). "Human leukocyte antigen class I and II alleles and risk of cervical neoplasia: results from a population-based study in Costa Rica". J. Infect. Dis. 184 (10): 1310–4. doi: 10.1086/324209 . PMID   11679920.
  5. ↑ Bhattacharya P, Sengupta S (October 2007). "Predisposition to HPV16/18-related cervical cancer because of proline homozygosity at codon 72 of p53 among Indian women is influenced by HLA-B*07 and homozygosity of HLA-DQB1*03". Tissue Antigens. 70 (4): 283–93. doi:10.1111/j.1399-0039.2007.00894.x. PMID   17767549.
  6. ↑ Rybicki BA, Iannuzzi MC (March 2004). "Sarcoidosis and human leukocyte antigen class I and II genes: it takes two to tango?". Am. J. Respir. Crit. Care Med. 169 (6): 665–6. doi:10.1164/rccm.2401005. PMID   15003948.
  7. ↑ Grunewald J, Eklund A, Olerup O (March 2004). "Human leukocyte antigen class I alleles and the disease course in sarcoidosis patients". Am. J. Respir. Crit. Care Med. 169 (6): 696–702. CiteSeerX   10.1.1.321.2788 . doi:10.1164/rccm.200303-459OC. PMID   14656748.
  8. ↑ Harjacek M, Margetić T, Kerhin-Brkljacić V, Martinez N, Grubić Z (2008). "HLA-B*27/HLA-B*07 in combination with D6S273-134 allele is associated with increased susceptibility to juvenile spondyloarthropathies". Clin. Exp. Rheumatol. 26 (3): 498–504. PMID   18578977.
  9. ↑ Raha-Chowdhury R, Bowen DJ, Burnett AK, Worwood M (June 1995). "Allelic associations and homozygosity at loci from HLA-B to D6S299 in genetic haemochromatosis". J. Med. Genet. 32 (6): 446–52. doi:10.1136/jmg.32.6.446. PMC   1050484 . PMID   7666396.
  10. ↑ "Une découverte québécoise pourrait permettre d'identifier les patients à risque d'une forme grave de la COVID-19". 12 October 2021.
  11. ↑ https://ici.radio-canada.ca/nouvelle/1830925/covid-identification-rapide-patients-risque-maladie-grave/
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