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-DP is a protein/peptide-antigen receptor and graft-versus-host disease antigen that is composed of 2 subunits, DPα and DPβ. DPα and DPβ are encoded by two loci, HLA-DPA1 and HLA-DPB1, that are found in the MHC Class II region in the Human Leukocyte Antigen complex on human chromosome 6 . Less is known about HLA-DP relative to HLA-DQ and HLA-DR but the sequencing of DP types and determination of more frequent haplotypes has progressed greatly within the last few years.
HLA-A25 (A25) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α25 subset of HLA-A α-chains. For A25, the alpha "A" chain are encoded by the HLA-A*25 allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*2501. A25 and A*25 are almost synonymous in meaning. A25 is a split antigen of the broad antigen serotype A10. A25 is a sister serotype of A26, A34, A43, and A66.
HLA-B5 (B5) is an HLA-B serotype. B5 is a broad antigen serotype that recognizes the B51 and B52 split antigen serotypes.
HLA-B*82 (B*82) is an HLA-B allele-group. There is no current useful serotyping for HLA-B*82 gene products. B*8201 was first identified by sequence analysis and appears to be derived by gene conversion between B*5602 and another HLA class I allele., later B*8202 was identified in a caucasian and was suggested to be ancestral to B*8201, as product between gene conversion of B*5602 allele and B*4501 allele. B*82 is more common in East Africa, Kenya and Sudan, the frequency of B*8201 is found in the peoples to the west, sporadically in Central and West Africa, B*8202 is found in Sudan and Saudi Arabia.
HLA-B81 (B81) is an HLA–B serotype. The serotype identifies the HLA-B*8101 and B*8102 gene products. B81 is more common in Subsaharan Africa. While there is a B81 serotype, serotyping of B81 is poor when simultaneously tested with anti-B7 or B48 antibodies.
HLA-B73 (B73) is an HLA-B serotype. The serotype identifies the HLA-B*7301 gene product. Part of B*7301 is similar to the HLA-B22 family, however part resembles the domains seen in other apes. B73 is more common in Western Indian Ocean, Mediterranean and Africa.
HLA-B53 (B53) is an HLA-B serotype. The serotype identifies the more common HLA-B*53 gene products. The B53 sequence is identical to B35 but short sequence specifies a Bw4 rather than a Bw6 motif, indicating B53 is a recent product of gene conversion. This suggests an origin for HLA-B53 involving a gene conversion of HLA-B35 by an allele containing this Bw4 sequence.
HLA-B48 (B48) is an HLA-B serotype. The serotype identifies the more common HLA-B*48 gene products. B48 is most common along the West Pacific Rim, Americas indigenous peoples and Northern Eurasians. B*4801 is part of a group of alleles including B*4201 that share Intron 1 sequence with B*0702, which is common over Western and Central Asia, and has a distribution indicating an early and long presence in Eurasian humans. A*48 appears to be the result of a recombination event that occurred early in the settlement history of Central Asia that then spread eastward into the NW Pacific rim and the New World.
HLA-B47 (B47) is an HLA–B serotype. The serotype identifies the HLA-B*47 gene products. Comparison of B47 nucleotide sequence with other HLA-B sequences shows a segment of 228 bp identical with B44 in the alpha 1 domain and a segment of 218 bp identical with B27 in the alpha 2 domain, but only a 91 bp segment of identity with B13 in the alpha 1 domain. The complex pattern of substitutions and their degree of divergence indicate that HLA-B13 and HLA-Bw47 alleles are not related by a simple mutational event. B47 is linked to a gene that causes adrenal deficiency. B47 is generally low in frequency and with highest known frequencies in Central and Western Africa.
HLA-B61 (B61) is an HLA - B serotype. B61 is a split antigen serotype that recognizes certain B40 serotypes.
HLA-B40 (B40) is an HLA - B serotype. B40 is composed of the B60 and B61 split antigen serotypes.
HLA-B14 (B14) is a HLA-B serotype. The serotype identifies the B*45 gene-allele protein products of HLA-B.
HLA-B58 (B58) is an HLA-B serotype. B58 is a split antigen from the B17 broad antigen, the sister serotype B57. The serotype identifies the more common HLA-B*58 gene products. B*5801 is associated with allopurinol induced inflammatory necrotic skin disease.
HLA-B15 (B15) is an HLA-B serotype. The serotype identifies the B*15 gene-allele protein products of HLA-B.
HLA-B75 (B75) is an HLA-B serotype. The serotype identifies certain B*15 gene-allele protein products of HLA-B.
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-Cw4 (Cw4) is a human leukocyte antigen serotype within HLA-C serotype group. Cw4 is determined by the antibody recognition of α4 subset of HLA-Cw α-chains. For the serotype Cw4, the alpha chain are encoded by the HLA-Cw*04 allele group and the β-chain are encoded by B2M locus. Cw4 and Cw*04 are almost synonymous in meaning. Cw4 is more common in Southeast Europe, where it is part of the Cw4-B35 haplotype.
Steven GE Marsh BSc ARCS PhD FRCPath, is a British Immunogeneticist and leader in the field of histocompatibility and immunogenetics having published more than 400 scientific papers on the subject. Marsh is Professor of Immunogenetics within University College London and the Chief Bioinformatics and Immunogenetics Officer at the charity Anthony Nolan where his heads the HLA Informatics Group.
IMGT or the international ImMunoGeneTics information system is a collection of databases and resources for immunoinformatics, particularly the V, D, J, and C gene sequences, as well as a providing other tools and data related to the adaptive immune system. IMGT/LIGM-DB, the first and still largest database hosted as part of IMGT contains reference nucleotide sequences for 360 species' T-cell receptor and immunoglobulin molecules, as of 2023. These genes encode the proteins which are the foundation of adaptive immunity, which allows highly specific recognition and memory of pathogens.
