II. Definitions

  1. Major Histocompatibility Complex or MHC (Human Leukocyte Antigen or HLA Complex)
    1. Polymorphic genes located on Chromosome 6 short arm
    2. MHC genes encode glycoproteins MHC Class 1 and MHC Class 2
  2. Human Leukocyte Antigen (HLA)
    1. Antigens processed (converted to peptides) and presented via MHC molecules on surface of Antigen presenting cells (APC)

III. Physiology: MHC Haplotypes

  1. Each person has 2 sets of MHC genes (one on each Chromosome 6)
  2. Each Chromosome 6 encodes three MHC-1 genes and three MHC-2 genes
    1. For each of the 6 encoded genes many variations exist
    2. The 6 encoded MHC gene variants (or Alleles) on each Chromosome are inherited as a group (haplotype)
  3. Each MHC haplotype represents a unique collection of Alleles
    1. One MHC haplotype is inherited from one the father's 2 Chromosome 6, and one haplotype from the mother

IV. Types: MHC Class 1

  1. Function
    1. Presents peptides from processed endogenous Antigen (e.g. Intracellular Bacteria, intracellular Parasites, viruses)
    2. May be expressed on surface of any nucleated host cell
    3. Part of Cytosolic Pathway in which peptides are presented to CD8+ T-Cells (Cytotoxic T-Cells)
  2. Comprised of 2 polypeptide chains
    1. B2-Microglobulin Chain (12 kd)
    2. Alpha (heavy chain, 45 kd)
      1. Three subunits (a1, a2, a3)
      2. a3 is bound to cell membrane
      3. a1 and a2 together form a cleft between them that serves as the peptide binding site
  3. Genes (each group is inherited as part of a unique haplotype)
    1. HLA-A
    2. HLA-B
    3. HLA-C

V. Types: MHC Class 2

  1. Function
    1. Presents peptides from processed exogenous Antigen (extracellular Antigens)
    2. MHC-1 is expressed only on surface of Dendritic Cells, Macrophages, B-Cell (B-Lymphocyte)
    3. Part of Endocytic Pathway in which peptides are presented to CD4+ T-Cells (T-Helper Cells)
  2. Comprised of 2 polypeptide chains (alpha and beta)
    1. Alpha and Beta each have 2 subunits (a1, a2 and b1, b2)
    2. Subunits a2 and b2 are bound to cell membrane
    3. Subunits a1 and b1 together form a cleft between them that serves as the peptide binding site
  3. Genes (each group is inherited as part of a unique haplotype)
    1. HLA-DP
    2. HLA-DQ
    3. HLA-DR

VI. References

  1. Mahmoudi (2014) Immunology Made Ridiculously Simple, MedMaster, Miami, FL

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Related Studies

Ontology: Histocompatibility Antigens Class I (C0019629)

Definition (MSH) Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.
Definition (NCI) Found on virtually every cell, MHC (Major Histocompatibility, HLA) Class-I (Antigens) Proteins consist of noncovalently bound polymorphic 44-kDa MHC membrane glycoprotein and nonpolymorphic 12-kDa b2-microglobulin. The HLA antigens are encoded by closely linked multiallelic genes of the HLA (MHC) complex, a region containing several genetic loci (HLA-A, -B, -C, -DP, -DQ, -DR, -MB, -MT, and -Te).
Definition (CSP) large transmembrane, polymorphic glycoproteins noncovalently associated with nonpolymorphic beta 2-microglobulin; in humans, three structural genes on chromosome 6 code for the HLA-A, HLA-B and HLA-C antigens, and in mice three genes on chromosome 17 code for the H-2 antigens; class I antigens are found on most nucleated cells, are recognized during graft rejection, restrict cell-mediated lysis of virus infected cells, and are associated with rheumatologic diseases and certain malignant disorders.
Concepts Amino Acid, Peptide, or Protein (T116) , Immunologic Factor (T129)
MSH D015395
English Antigens, Class I, Class I Antigens, Class I Histocompatibility Antigens, Class I Major Histocompatibility Antigens, I Antigens, Class, Human Leukocyte Antigen, Histocompatibility Antigens Class I, MHC class I antigen, HISTOCOMPATIBILITY ANTIGENS CLASS 01, Histocompatibility Antigens Class I [Chemical/Ingredient], Class I MHC Protein, Complex Class 1, Histocompatibility Antigen, Class I, MHC Class I Molecule, MHC Class I Protein, Major Histocompatibility Complex Class 1
Swedish Histokompatibilitetsantigener klass I
Czech histokompatibilita - antigeny třídy I
Finnish Kudossopeutuvuusantigeenit luokka I
French Antigènes d'histocompatibilité de classe 1, Antigènes du CMH de classe I, Antigènes d'histocompatibilité majeure de classe I, Antigène d'histocompatibilité de classe I, Antigènes d'histocompatibilité de classe I, Antigènes de classe I, Antigène d'histocompatibilité classe I, Antigènes de classe I du complexe majeur d'histocompatibilité, Antigènes majeurs d'histocompatibilité de classe I
Russian ANTIGENY GISTOSOVMESTIMOSTI KLASSA I, GISTOSOVMESTIMOSTI ANTIGENY KLASSA I, KLASSA I ANTIGENY, АНТИГЕНЫ ГИСТОСОВМЕСТИМОСТИ КЛАССА I, ГИСТОСОВМЕСТИМОСТИ АНТИГЕНЫ КЛАССА I, КЛАССА I АНТИГЕНЫ
German HISTOKOMPATIBILITÄTSANTIGENE KLASSE 01, Klasse-I-Antigene, Histokompatibilitätsantigene Klasse I
Spanish Antígenos de Histocompatibilidad Clase I, Antígenos Clase I de Histocompatibilidad, Antígenos Clase I
Croatian HISTOKOMPATIBILNI ANTIGENI SKUPINE I
Polish Antygeny zgodności tkankowej klasy I
Japanese HLA-クラス1, 組織適合抗原I, クラス1抗原, 組織適合性抗原クラス1, 組織適合抗原1, HLA-クラスI, HLAクラス1抗原, HLAクラスI抗原, クラスI抗原, 抗原-HLAクラス1, 抗原-HLAクラスI
Italian Antigeni di istocompatibilita' di classe I
Portuguese Antígenos Classe I, Antígenos de Histocompatibilidade Classe I

Ontology: Histocompatibility Antigens Class II (C0019630)

Definition (NCI_NCI-GLOSS) One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign substances. These antigens vary from person to person, and human leukocyte antigen tests are done before organ transplantation to find out if tissues match between a donor and a recipient.
Definition (NCI) MHC Class-II Proteins are non-covalently linked polymorphic alpha/beta transmembrane glycoproteins. The immunological function of MHC Class-II proteins is to bind and present antigenic peptides on the surfaces of cells for recognition by the antigen-specific T cell receptors of lymphocytes. These proteins plays an important role in the mediation of immune response.
Definition (MSH) Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.
Definition (CSP) large transmembrane non-covalently linked glycoproteins; class II antigens in humans are called HLA-D antigens and coded on a gene on chromosome 6; in mice two genes named IA and iE on chromosome 17 code for the H-2 antigens; class II antigens are found on B-lymphocytes, macrophages, epidermal cells and sperm and are thought to mediate the competence of and cellular cooperation in the immune response.
Concepts Amino Acid, Peptide, or Protein (T116) , Immunologic Factor (T129)
MSH D000949
LNC LP32739-2
English Antigen, Class II, Antigens, Class II, Antigens, Ia, Antigens, Ia-Like, Antigens, Immune Response, Antigens, Immune-Response-Associated, Class II Antigen, Class II Antigens, Class II Histocompatibility Antigens, Class II Major Histocompatibility Antigens, Ia Antigens, Ia-Like Antigens, Immune Response Antigens, Immune-Response-Associated Antigens, I-A-Antigen, I-A Antigen, IA Antigen, Antigen, I-A, Antigen, IA, I A Antigen, Ia Like Antigens, Ia antigen, Immune Response Associated Antigens, Human Leukocyte Antigen, Histocompatibility Antigens Class II, MHC class II antigen, HISTOCOMPATIBILITY ANTIGENS CLASS 02, ANTIGENS IR, IR ANTIGENS, Histocompatibility Antigens Class II [Chemical/Ingredient], Human Leukocyte Antigens, Ia antigens, HLA, human lymphocyte antigen, human leukocyte antigen, Class II MHC Protein, Histocompatibility Antigen, Class II, MHC Class II Molecule, MHC Class II Protein, Major Histocompatibility Complex Class II
Swedish Histokompatibilitetsantigener klass II
Czech histokompatibilita - antigeny třídy II
Finnish Kudossopeutuvuusantigeenit luokka II
French Antigènes d'histocompatibilité de classe II, Antigène d'histocompatibilité de classe II, Antigènes d'histocompatibilité de classe 2, Antigènes du CMH de classe II, Antigènes de classe II du complexe majeur d'histocompatibilité, Antigènes majeurs d'histocompatibilité de classe II, Antigène de classe II, Antigènes d'histocompatibilité majeurs de classe II, Antigène I-A, Antigène IA, Antigènes de classe II, Antigènes associés à la réponse immune, Antigènes de la réponse immune
Italian Antigene di classe II, Antigeni Ia, Antigeni di classe II, Antigeni di istocompatibilità di classe II, Antigeni tipo Ia, Antigeni del complesso maggiore di istocompatibilità di classe II, Antigene IA, Antigeni asociati alla risposta immunitaria, Antigeni di risposta immunitaria, Antigeni di istocompatibilita' di classe II
Russian GISTOSOVMESTIMOSTI ANTIGENY KLASSA II, IMMUNNO-ASSOTSIIROVANNYE ANTITELA, ANTIGENY GISTOSOVMESTIMOSTI KLASSA II, IMMUNNOGO OTVETA ANTITELA, IA-PODOBNYE ANTIGENY, TKANEVOI SOVMESTIMOSTI ANTIGENY KLASSA II, ANTIGENY IMMUNNOGO OTVETA, KLASSA II ANTIGENY, IA ANTIGENY, IA АНТИГЕНЫ, IA-ПОДОБНЫЕ АНТИГЕНЫ, АНТИГЕНЫ ГИСТОСОВМЕСТИМОСТИ КЛАССА II, АНТИГЕНЫ ИММУННОГО ОТВЕТА, ГИСТОСОВМЕСТИМОСТИ АНТИГЕНЫ КЛАССА II, ИММУННО-АССОЦИИРОВАННЫЕ АНТИТЕЛА, ИММУННОГО ОТВЕТА АНТИТЕЛА, КЛАССА II АНТИГЕНЫ, ТКАНЕВОЙ СОВМЕСТИМОСТИ АНТИГЕНЫ КЛАССА II
Japanese HLAクラス2抗原, Ia抗原, 組織適合抗原2, 免疫応答抗原, 抗原-HLAクラスII, HLA-クラスII, 抗原-HLAクラス2, IA抗原, クラス2抗原, 免疫応答関連抗原, HLAクラスII抗原, 抗原-免疫応答, IA様抗原, 組織適合性抗原クラス2, 免疫関連抗原, クラスII抗原, HLA-クラス2, 組織適合抗原II
German HISTOKOMPATIBILITÄTSANTIGENE KLASSE 02, Antigene, Immunantwort-, Ia-Antigene, Immunantwort-Antigene, Immunantwort-assoziierte Antigene, Klasse-II-Antigene, Histokompatibilitätsantigene Klasse II, Ia-ähnliche-Antigene
Spanish Antígenos de Histocompatibilidad Clase II, Antígenos Similes-Ia, Antígenos Clase II de Histocompatibilidad, Antígenos Clase II, Antígenos Ia, Antígenos de Respuesta Inmune Asociados, Antígenos de Respuesta Inmune
Croatian HISTOKOMPATIBILNI ANTIGENI SKUPINE II
Polish Antygeny odpowiedzi immunologicznej, Antygeny zgodności tkankowej klasy II
Portuguese Antígenos Ia-like, Antígenos Similares a Ia, Antígenos Tipo Ia, Antígenos Classe II, Antígenos de Histocompatibilidade Classe II, Antígenos de Resposta Imune Associados, Antígenos de Resposta Imune, Antígenos Ia

Ontology: HLA Antigens (C0019721)

Definition (MSH) Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.
Concepts Amino Acid, Peptide, or Protein (T116) , Immunologic Factor (T129)
MSH D006680
SnomedCT 47038001
LNC LP57611-3, LP29288-5, LP7806-5, LP29295-0, MTHU018438
English Antigens, HL-A, Antigens, HLA, Antigens, Leukocyte, HL A Antigens, HL-A Antigens, Leukocyte Antigens, HLA antigens, Antigens, Human Leukocyte, Human Leukocyte Antigens, Leukocyte Antigens, Human, HLA antigen (substance), Human leucocyte antigen (HLA) antigen, Human leukocyte antigen (HLA) antigen, HLA A 00 ANTIGENS, HLA factors, HLA Antigens [Chemical/Ingredient], HLA, antigens leukocytes, antigen human leukocytes, hlas, human leucocyte antigen, antigens hla, antigens human leucocyte, hl antigens, antigen human leukocyte, leukocyte antigen, antigen human leucocyte, hla antigen, hla antigens, human leukocyte antigens, antigens human leucocytes, Human leucocyte antigen (HLA), human leukocyte antigen, Human leukocyte antigen (substance), Human leukocyte antigen (HLA) antigen (substance), HLA Ag, human histocompatibility complex derived antigens Antigen, HLA antigen, Human leucocyte antigen, HLA - Human leucocyte antigen, HLA - Human leukocyte antigen, Human leukocyte antigen, HLA antigen, NOS, HLA Antigens
Spanish antígeno HLA, antígeno de histocompatibilidad, antígeno leucocítico humano (sustancia), antígeno leucocítico humano, antígeno de histocompatibilidad (sustancia), Antígenos de Leucocito Humano, Antígenos de Leucocitos, Antígenos HLA
Swedish HLA-antigener
Czech HLA antigeny
Finnish HL-antigeenit
Italian Antigeni umani leucocitari, Antigeni HL-A, Antigeni leucocitari, Antigeni HLA
Russian HLA ANTIGENY, ANTIGENY CHELOVEKA, KLASS I, ANTIGENY LEIKOTSITARNYE, ANTIGENY LEIKOTSITOV CHELOVEKA, SD ANTIGENY CHELOVEKA, CHELOVECHESKIE ANTIGENY KLASSA I, LD ANTIGENY CHELOVEKA, HLA АНТИГЕНЫ, LD АНТИГЕНЫ ЧЕЛОВЕКА, SD АНТИГЕНЫ ЧЕЛОВЕКА, АНТИГЕНЫ ЛЕЙКОЦИТАРНЫЕ, АНТИГЕНЫ ЛЕЙКОЦИТОВ ЧЕЛОВЕКА, АНТИГЕНЫ ЧЕЛОВЕКА, КЛАСС I, ЧЕЛОВЕЧЕСКИЕ АНТИГЕНЫ КЛАССА I
Japanese HLA抗原, ヒト白血球抗原, 抗原-HLA, 白血球抗原
French Antigènes HLA, Antigène HLA, Antigènes des leucocytes humains
German HLA A ANTIGENE, HLA-Antigene, Human Leukocyte Antigene, Leukozytenantigene
Croatian HLA ANTIGENI
Polish Antygeny HLA
Portuguese Antígenos de Leucócitos Humanos, Antígenos de Leucócitos, Antígenos HLA

Ontology: Major Histocompatibility Complex (C0024518)

Definition (CSP) genetic region found in all mammals whose products are primarily reponsible for the rapid rejection of grafts between individuals and which signal between lymphocytes and cells expressing antigen; H-2 in mouse and HLA in humans.
Definition (MSH) The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.
Concepts Gene or Genome (T028)
MSH D008285
SnomedCT 70828002
English Complex, Histocompatibility, Complex, Major Histocompatibility, Complices, Histocompatibility, Complices, Major Histocompatibility, Histocompatibility Complex, Histocompatibility Complex, Major, Histocompatibility Complices, Histocompatibility Complices, Major, Major Histocompatibility Complex, Major Histocompatibility Complices, major histocompatibility complex, histocompatibility complex, mhc, major histocompatibility complex (MHC), Major histocompatibility complex, MHC, Major histocompatibility complex (substance), Major histocompatibility complex, NOS
Swedish Histokompatibilitetskomplex
Czech histokompatibilní komplex, hlavní histokompatibilní komplex
Finnish MHC
French Complexe majeur d'histocompatibilité, CMH (Complexe Majeur d'Histocompatibilité), Complexe CMH, Complexe d'histocompatibilité, Complexe CMH (Complexe Majeur d'Histocompatibilité)
Italian Complesso di istocompatibilità, Complesso cromosomico principale di istocompatibilità
Russian GISTOSOVMESTIMOSTI GLAVNYI KOMPLEKS, KOMPLEKS GISTOSOVMESTIMOSTI, GISTOSOVMESTIMOST', GLAVNYI KOMPLEKS, ГИСТОСОВМЕСТИМОСТИ ГЛАВНЫЙ КОМПЛЕКС, ГИСТОСОВМЕСТИМОСТЬ, ГЛАВНЫЙ КОМПЛЕКС, КОМПЛЕКС ГИСТОСОВМЕСТИМОСТИ
Croatian GLAVNI KOMPLEKS TKIVNE SNOŠLJIVOSTI
Polish Kompleks główny zgodności tkankowej, Kompleks MHC, Główny kompleks zgodności tkankowej, MHC
Japanese 主組織適合遺伝子複合系, 主要組織適合遺伝子複合体, 主組織適合性複合系, 主組織適合性遺伝子複合系, 主組織適合複合系, 主要組織適合性抗原系, 主要組織適合性複合系, 主要組織適合性遺伝子複合体, 主要組織適合性遺伝子複合系, 主要組織適合抗原系, 主要組織適合複合体, 主要組織適合複合系, 組織適合性複合体
Norwegian MHC, Sterke vevsforlikelighetsantigener
Spanish Complejo Principal de Histocompatibilidad, CMH, complejo mayor de histocompatibilidad (sustancia), complejo mayor de histocompatibilidad, Complejo de Histocompatibilidad, Complejo Mayor de Histocompatibilidad
Portuguese Complexo de Histocompatibilidade Principal, Complexo de Histocompatibilidade, Complexo Principal de Histocompatibilidade
German MHC, Haupt-Histokompatibilitätskomplex, Histokompatibilitätskomplex
Dutch Major histocompatibility complex