Major histocompatibility complex

MHCmajor histocompatibility complex (MHC)HLA locimajor histocompatibility complex class IIIMHC moleculesstructures on the cell surfaceMHC class IIMHC moleculeclass IClass I MHC
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates, which in turn determines histocompatibility.wikipedia
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Human leukocyte antigen

HLAhuman leukocyte antigenshuman leukocyte antigen (HLA)
The human MHC is also called the HLA (human leukocyte antigen) complex (often just the HLA).
The human leukocyte antigen (HLA) system or complex is a gene complex encoding the major histocompatibility complex (MHC) proteins in humans.

Histocompatibility

histocompatibility antigenshistocompatiblecompatible
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates, which in turn determines histocompatibility.
Histocompatibility, or tissue compatibility, is the property of having the same, or sufficiently similar, alleles of a set of genes called human leukocyte antigens (HLA), or major histocompatibility complex (MHC).

Immune system

immuneimmune responseimmune function
The presented antigen can be either self or non-self, thus preventing an organism's immune system targeting its own cells.
To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.

MHC class I

class IMHC Iclass I MHC
The MHC gene family is divided into three subgroups: MHC class I, MHC class II, and MHC class III.
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules (the other being MHC class II) and are found on the cell surface of all nucleated cells in the bodies of jawed vertebrates.

MHC class II

MHC IIclass IIHLA class II
The MHC gene family is divided into three subgroups: MHC class I, MHC class II, and MHC class III.
MHC class II molecules are a class of major histocompatibility complex (MHC) molecules normally found only on professional antigen-presenting cells such as dendritic cells, mononuclear phagocytes, some endothelial cells, thymic epithelial cells, and B cells.

MHC class III

The MHC gene family is divided into three subgroups: MHC class I, MHC class II, and MHC class III.
MHC class III is a group of proteins belonging the class of major histocompatibility complex (MHC).

Major histocompatibility complex and sexual selection

Major Histocompatibility Complexmajor histocompatibility complex (MHC)MHC sexual selection
Major histocompatibility complex and sexual selection has been observed in male mice making mate choices of females with different MHCs and thus demonstrating sexual selection.
The major histocompatibility complex in sexual selection concerns how major histocompatibility complex (MHC) molecules allow for immune system surveillance of the population of protein molecules in a host's cells.

Antigen presentation

antigen recognitionpresentedpresent
Diversity of antigen presentation, mediated by MHC classes I and II, is attained in at least three ways: (1) an organism's MHC repertoire is polygenic (via multiple, interacting genes); (2) MHC expression is codominant (from both sets of inherited alleles); (3) MHC gene variants are highly polymorphic (diversely varying from organism to organism within a species). Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation
Because T cells recognise only fragmented antigens displayed on cell surfaces, antigen processing must occur before the antigen fragment, now bound to the major histocompatibility complex (MHC), is transported to the surface of the cell, a process known as presentation, where it can be recognized by a T cell receptor.

Baruj Benacerraf

Baruj '''BenacerrafBaruj Benacerraf, M.D.Benacerraf, Baruj
For this work, Snell was awarded the 1980 Nobel Prize in Physiology or Medicine, together with Baruj Benacerraf and Jean Dausset.
Baruj Benacerraf (October 29, 1920 – August 2, 2011) was a Venezuelan-American immunologist, who shared the 1980 Nobel Prize in Physiology or Medicine for the "discovery of the major histocompatibility complex genes which encode cell surface protein molecules important for the immune system's distinction between self and non-self."

T-cell receptor

T cell receptorTCRT-cell receptors
MHC is also the chaperone for intracellular peptides that are complexed with MHCs and presented to T cell receptors (TCRs) as potential foreign antigens. Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation
The T-cell receptor (TCR) is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.

Jean Dausset

Dausset, Jean
For this work, Snell was awarded the 1980 Nobel Prize in Physiology or Medicine, together with Baruj Benacerraf and Jean Dausset.
Dausset received the Nobel Prize in Physiology or Medicine in 1980 along with Baruj Benacerraf and George Davis Snell for their discovery and characterisation of the genes making the major histocompatibility complex.

Epitope

epitopesantigenic determinantantigenic determinants
Each MHC molecule on the cell surface displays a molecular fraction of a protein, called an epitope. Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation
T cell epitopes are presented on the surface of an antigen-presenting cell, where they are bound to MHC molecules.

HLA-B27

HLA B27B27HLA-B*27
HLA-B27 is an example.
Human leukocyte antigen (HLA) B27 (subtypes B*2701-2759) is a class I surface antigen encoded by the B locus in the major histocompatibility complex (MHC) on chromosome 6 and presents antigenic peptides (derived from self and non-self antigens) to T cells.

T cell

T cellsT-cellT-cells
The main function of MHC molecules is to bind to antigens derived from pathogens and display them on the cell surface for recognition by the appropriate T-cells. Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation
These self-antigens are expressed by thymic cortical epithelial cells on MHC molecules on the surface of cortical epithelial cells.

CD8

CD8 + CD8+CD8B
Class I MHC molecules have β 2 microglobulin subunit which can only be recognised by CD8 co-receptors. Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation
Like the TCR, CD8 binds to a major histocompatibility complex (MHC) molecule, but is specific for the class I MHC protein.

Natural killer cell

NK cellsnatural killer cellsNK cell
As a lineage of leukocytes, lymphocytes reside in peripheral lymphoid tissues, including lymphoid follicles and lymph nodes, and include B cells, T cells, and natural killer cells (NK cells).
Typically, immune cells detect the major histocompatibility complex (MHC) presented on infected cell surfaces, triggering cytokine release, causing lysis or apoptosis.

MHC restriction

MHC-restricted antigen recognitionpositive selectionRestriction
T cells become activated by binding to the peptide-binding grooves of any MHC molecule that they were not trained to recognize during positive selection in the thymus.
MHC-restricted antigen recognition, or MHC restriction, refers to the fact that a T cell can interact with a self-major histocompatibility complex molecule and a foreign peptide bound to it, but will only respond to the antigen when it is bound to a particular MHC molecule.

Allorecognition

historecognitionvegetative incompatibility
Tissue allorecognition: MHC molecules in complex with peptide epitopes are essentially ligands for TCRs.
The adaptive or "specific" immune system in its fully qualified form (i.e. based on major histocompatibility complex (MHC), T-cell receptors (TCR), and antibodies) exists only in jawed vertebrates, but an independently evolved adaptive immune system has been identified in hagfish and lampreys (non-jawed vertebrates).

HLA-A

HLA-serotype tutorialAhla-a antigens
In humans, MHC class I comprises HLA-A, HLA-B, and HLA-C molecules.
HLA is a major histocompatibility complex (MHC) antigen specific to humans.

Mate choice

mate selectionfemale choicemate preference
Major histocompatibility complex and sexual selection has been observed in male mice making mate choices of females with different MHCs and thus demonstrating sexual selection.
However, the genetic compatibility model is limited to specific traits due to complex genetic interactions (e.g. major histocompatibility complex in humans and mice).

Adaptive immune system

adaptive immunityadaptive immune responseadaptive
The major histocompatibility complex (MHC) is a set of genes that code for cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates, which in turn determines histocompatibility.
In the lymph node, the dendritic cell displays these non-self antigens on its surface by coupling them to a receptor called the major histocompatibility complex, or MHC (also known in humans as human leukocyte antigen (HLA)).

HLA-B

Bhla-b antigensHLA-B*5701
In humans, MHC class I comprises HLA-A, HLA-B, and HLA-C molecules.
HLA is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species.

Lymphocyte

lymphocyteslymphocyticlymphoid cells
As a lineage of leukocytes, lymphocytes reside in peripheral lymphoid tissues, including lymphoid follicles and lymph nodes, and include B cells, T cells, and natural killer cells (NK cells).
NK cells distinguish infected cells and tumors from normal and uninfected cells by recognizing changes of a surface molecule called MHC (major histocompatibility complex) class I.

Immunoglobulin superfamily

Immunoglobulin (Ig) superfamilyimmunoglobulinIg
Antigen presentation: MHC molecules bind to both T cell receptor and CD4/CD8 co-receptors on T lymphocytes, and the antigen epitope held in the peptide-binding groove of the MHC molecule interacts with the variable Ig-Like domain of the TCR to trigger T-cell activation

Polymorphism (biology)

polymorphismpolymorphicmorph
Diversity of antigen presentation, mediated by MHC classes I and II, is attained in at least three ways: (1) an organism's MHC repertoire is polygenic (via multiple, interacting genes); (2) MHC expression is codominant (from both sets of inherited alleles); (3) MHC gene variants are highly polymorphic (diversely varying from organism to organism within a species).
The genes of the major histocompatibility complex (MHC) are highly polymorphic, and this diversity plays a very important role in resistance to pathogens.