Changes

==MHC II==

==MHC II==

===Structure===

===Structure===

MHC class II is expressed mainly on [[Macrophages|macrophages]], [[T cell differentiation#Antigen Presentation by Dendritic Cells|dendritic cells]] and [[B cells|B-lymphocytes]]. MHC class II consists of membrane-associated α and β chains with each chain being a transmembrane glycoprotein. The extracellular parts of each chain have two Ig-like domains - α1 and α2, β1 and β2. The β2 domain is responsible for the activation of [[T cells|T helper cells]] through the interaction with the CD4⁺ on the cell surface of the T helper cells. The outer domains (α1 and β1) are variable and the inner domains (α2 and β2) are constant.

MHC class II is expressed mainly on [[Macrophages|macrophages]], [[T cell differentiation#Antigen Presentation by Dendritic Cells|dendritic cells]] and [[B cells|B-lymphocytes]]. MHC class II consists of membrane-associated α and β chains with each chain being a transmembrane glycoprotein. The extracellular parts of each chain have two Ig-like domains - α1 and α2, β1 and β2. The β2 domain is responsible for the activation of [[T cells|T helper cells]] through the interaction with the CD4⁺ on the cell surface of the T helper cells. The outer domains (α1 and β1) are variable and the inner domains (α2 and β2) are constant.

*The MHC II-antigen complex is then secreted to the cell surface for presentation to [[T_cells#Helper_CD4.2B|CD4⁺ T-cells]]

*The MHC II-antigen complex is then secreted to the cell surface for presentation to [[T_cells#Helper_CD4.2B|CD4⁺ T-cells]]

[[File:MHC Class II Presentation.png|thumb|right|300px|MHC Class II Presentation pathway]]

[[File:MHC Class II Presentation.png|thumb|left|200px|MHC Class II Presentation pathway - RJ Francis, RVC, 2012]]

==Antigen/MHC Interaction==

==Antigen/MHC Interaction==