MHC Molecules: Difference between revisions
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MHC Molecules play a key role in the presentation of [[Antigens|antigens]]. The foreign [[Proteins|protein]] must be processed into a [[Peptide|peptide]] before it can be presented by MHC. This processing occurs in the [[Proteasome|proteasome]] of the [[Cell|cell]]. There are 2 types of MHC Molecule; Class 1 MHC & Class 2 MHC. <br> | MHC [[Molecules|Molecules]] play a key role in the presentation of [[Antigens|antigens]]. The foreign [[Proteins|protein]] must be processed into a [[Peptide|peptide]] before it can be presented by MHC. This processing occurs in the [[Proteasome|proteasome]] of the [[Cell|cell]]. There are 2 types of MHC Molecule; Class 1 MHC & Class 2 MHC. <br> | ||
=== MHC Class 1 === | === MHC Class 1 === | ||
MHC Class 1 molecules are expressed in all nucleated cells. These are involved in the presentation of endogenous [[Antigens|antigens]] (those found intracellularly). Presentation of these endogenous antigens is recognised by [[Cytotoxic T cells|Cytotoxic T cells]] that destroy the antigen via a mechanism involving the use of [[Granzyme|Granzyme]] and [[Perfornin|Perfornin]].<br>MHC class 1 molecules have 3 alpha subunits and 1 beta microglobin subunit. Both alpha 1 and 2 form the antigen presenting region of the molecule. MHC class 1 has only one transmembrane domain that anchors it into the cell membrane. | MHC Class 1 molecules are expressed in all nucleated cells. These are involved in the presentation of endogenous [[Antigens|antigens]] (those found intracellularly). Presentation of these endogenous antigens is recognised by [[Cytotoxic T cells|Cytotoxic T cells]] that destroy the antigen via a mechanism involving the use of [[Granzyme|Granzyme]] and [[Perfornin|Perfornin]].<br>MHC class 1 molecules have 3 alpha subunits and 1 beta microglobin subunit. Both alpha 1 and 2 form the antigen presenting region of the molecule. MHC class 1 has only one transmembrane domain that anchors it into the cell membrane. | ||
=== MHC Class 2 === | === MHC Class 2 === | ||
Revision as of 16:22, 19 October 2012
MHC Molecules play a key role in the presentation of antigens. The foreign protein must be processed into a peptide before it can be presented by MHC. This processing occurs in the proteasome of the cell. There are 2 types of MHC Molecule; Class 1 MHC & Class 2 MHC.
MHC Class 1
MHC Class 1 molecules are expressed in all nucleated cells. These are involved in the presentation of endogenous antigens (those found intracellularly). Presentation of these endogenous antigens is recognised by Cytotoxic T cells that destroy the antigen via a mechanism involving the use of Granzyme and Perfornin.
MHC class 1 molecules have 3 alpha subunits and 1 beta microglobin subunit. Both alpha 1 and 2 form the antigen presenting region of the molecule. MHC class 1 has only one transmembrane domain that anchors it into the cell membrane.
MHC Class 2
MHC Class 2 are expressed in professional antigen presenting cells such as macrophages and B Cells. They present exogenous antigens (those made outside the cell). They bind peptides 18-20 amino acids long.
Unlike MHC Class 1 receptors, these molecules have two alpha and two beta subunits, with transmembrane spanning regions from alpha-2 and beta-2. The alpha-1 and beta-1 subunits form an anitgen presenting site.