HLA-A11
Encyclopedia
HLA-A11 is a human leukocyte antigen
serotype
within HLA-A
"A" serotype group. The serotype is determined by the antibody recognition of α11 subset of HLA-A α-chains. For A11, the alpha "A" chain are encoded by the HLA-A*11 allele group and the β-chain are encoded by B2M
locus. This group currently is dominated by A*1101. A11 and A*11 are almost synonymous in meaning.
A11 is more common in East Asia than elsewhere, it is part of a several long haplotype
s that appear to have been frequent in the ancient peoples of Asia.
, pulmonary tuberculosis, leprosy
, and cytomegalovirus
infection with epilepsy
.
These and other studies suggest an involvement between A11 and secondary effects of certain herpes virus infections.
A11 was also found increase in supraglottic cancer with poor 3 year survival. In osteosarcoma A11 was found elevated.
There is a strong association between anti-depressant induced hepatitis and HLA-A11. In autoimmune hepatitis, A11 has a synergistic effect, acting together with DR4 and DR3 to increase the odds of disease to over 300.
A11 is also part of a haplotype A11-Cw4-B35-DR1-DQ1 that is a second factor in the rapid progression of HIV. The involvement of non-Hodgkin's lymphoma primarily as a result of Epstein-Barr virus reinfection does not appear to be a cause in this acceleration.
infection. Examination of the virus itself has led to the discovery of strains that can all but turn off the A11-mediated class I response to the virus in A11 enriched peoples (see tables below). This ability to turn off the immune system and for the virus to remain active is a factor in carcinogenesis. Early studies of A serotypes revealed and association of A11 with Hodgkin's lymphoma
and recent studies have shown a complex involvement of Epstein-Barr virus infection as a consequence of low A11 control over infection.
Burkitt's lymphoma
eventually lead to the discovery of the virus, however this disease is more evident in Africa. An involvement in cytotoxic T-lymphocytes down-regulation in Burkitt's lymphoma was subsequently discovered, More recent studies show A11 is down-regulated, and that other genetic defects are a likely cause. The ability to present EB virus antigens revealed a defect in the process after antigen process but before TAP1 involvement. Other studies indicated that peptides bind A11 in delivery to the cell surface for CTL screening, but fall off, and are destroyed intracellularly. However, A3 and A11 can process and load antigens even when proteosome activity is diminished suggesting an alternative mechanism for loading which may benefit in recovery from some disease but impair recovery of others.
It appears that these and other viruses have learned to exploit some defect in the region surrounding A11 that allows the near complete shut-down of gene expression. Oddly, in Africa A11 is at very low frequencies, and homozygotes are rare, suggesting that other genetic susceptibilities may exist that steer the virus toward Burkitt's lymphoma.
resulting from human papillomavirus
infection
Human leukocyte antigen
The human leukocyte antigen system is the name of the major histocompatibility complex in humans. The super locus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6, and encodes cell-surface antigen-presenting proteins and...
serotype
Serotype
Serotype or serovar refers to distinct variations within a subspecies of bacteria or viruses. These microorganisms, viruses, or cells are classified together based on their cell surface antigens...
within HLA-A
HLA-A
HLA-A are a group of human leukocyte antigens that are encoded by the HLA-A locus on human chromosome 6p. The HLA genes constitute a large subset of the Major histocompatibility complex of humans. HLA-A is a component of certain MHC class I cell surface receptor isoforms that resides on the...
"A" serotype group. The serotype is determined by the antibody recognition of α11 subset of HLA-A α-chains. For A11, the alpha "A" chain are encoded by the HLA-A*11 allele group and the β-chain are encoded by B2M
B2M
B2M may refer to:*Boyz II Men, a singing group*Mitsubishi B2M, an aircraft*Back to Mine, a series of albums*Beta-2 microglobulin, a gene or protein*Business to machine, the practice of E-commerce where companies link directly to machines...
locus. This group currently is dominated by A*1101. A11 and A*11 are almost synonymous in meaning.
A11 is more common in East Asia than elsewhere, it is part of a several long haplotype
Haplotype
A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...
s that appear to have been frequent in the ancient peoples of Asia.
Serotype
Serotyping of A11 demonstrates better recognition of the *1101 gene products and poorer recognition of other A*11 gene products. There are ~40 recognized alleles of A*11. There is only one null classified as A11.In infectious disease
Associations have been observed between A11 and familial otosclerosisOtosclerosis
Otosclerosis is an abnormal growth of bone near the middle ear. It can result in hearing loss.-Clinical description:Otosclerosis can result in conductive and/or sensorineural hearing loss...
, pulmonary tuberculosis, leprosy
Leprosy
Leprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
, and cytomegalovirus
Cytomegalovirus
Cytomegalovirus is a viral genus of the viral group known as Herpesviridae or herpesviruses. It is typically abbreviated as CMV: The species that infects humans is commonly known as human CMV or human herpesvirus-5 , and is the most studied of all cytomegaloviruses...
infection with epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
.
These and other studies suggest an involvement between A11 and secondary effects of certain herpes virus infections.
A11 was also found increase in supraglottic cancer with poor 3 year survival. In osteosarcoma A11 was found elevated.
There is a strong association between anti-depressant induced hepatitis and HLA-A11. In autoimmune hepatitis, A11 has a synergistic effect, acting together with DR4 and DR3 to increase the odds of disease to over 300.
A11 is also part of a haplotype A11-Cw4-B35-DR1-DQ1 that is a second factor in the rapid progression of HIV. The involvement of non-Hodgkin's lymphoma primarily as a result of Epstein-Barr virus reinfection does not appear to be a cause in this acceleration.
Epstein-Barr Virus anomaly
There are at least a couple of forms of lymphoproliferative diseases that appear to arise from unresolved Epstein-Barr virusEpstein-Barr virus
The Epstein–Barr virus , also called human herpesvirus 4 , is a virus of the herpes family and is one of the most common viruses in humans. It is best known as the cause of infectious mononucleosis...
infection. Examination of the virus itself has led to the discovery of strains that can all but turn off the A11-mediated class I response to the virus in A11 enriched peoples (see tables below). This ability to turn off the immune system and for the virus to remain active is a factor in carcinogenesis. Early studies of A serotypes revealed and association of A11 with Hodgkin's lymphoma
Hodgkin's lymphoma
Hodgkin's lymphoma, previously known as Hodgkin's disease, is a type of lymphoma, which is a cancer originating from white blood cells called lymphocytes...
and recent studies have shown a complex involvement of Epstein-Barr virus infection as a consequence of low A11 control over infection.
Burkitt's lymphoma
Burkitt's lymphoma
Burkitt's lymphoma is a cancer of the lymphatic system...
eventually lead to the discovery of the virus, however this disease is more evident in Africa. An involvement in cytotoxic T-lymphocytes down-regulation in Burkitt's lymphoma was subsequently discovered, More recent studies show A11 is down-regulated, and that other genetic defects are a likely cause. The ability to present EB virus antigens revealed a defect in the process after antigen process but before TAP1 involvement. Other studies indicated that peptides bind A11 in delivery to the cell surface for CTL screening, but fall off, and are destroyed intracellularly. However, A3 and A11 can process and load antigens even when proteosome activity is diminished suggesting an alternative mechanism for loading which may benefit in recovery from some disease but impair recovery of others.
It appears that these and other viruses have learned to exploit some defect in the region surrounding A11 that allows the near complete shut-down of gene expression. Oddly, in Africa A11 is at very low frequencies, and homozygotes are rare, suggesting that other genetic susceptibilities may exist that steer the virus toward Burkitt's lymphoma.
Alleles
Disease Associations
A*1104 is associated with increased risk for cervical neoplasiaCervical cancer
Cervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
resulting from human papillomavirus
Papillomavirus
Papillomaviridae is an ancient taxonomic family of non-enveloped DNA viruses, collectively known as papillomaviruses. Several hundred species of papillomaviruses, traditionally referred to as "types", have been identified infecting all carefully inspected birds and mammals, but also a small number...
infection
A11-B Haplotypes
A11-B13- A11-Cw2-B13 (Li)
- A11-Cw9-B13 (Southern China & SE Asia)
- A11-C10-B13 Buyi
- A11-CBL-B13 Northern China