Changes

*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]]

=Antigen/MHC Interaction=

==Antigen/MHC Interaction==

* The MHC molecules do not recognise specific amino acid sequences of antigens

* The MHC molecules do not recognise specific amino acid sequences of antigens

** Instead, they recognise particular motifs of amino acids

** Instead, they recognise particular motifs of amino acids

** E.g. ruminants have no MHC class II DP

** E.g. ruminants have no MHC class II DP

=MHC and Disease=

==MHC and Disease==

* Antigen from a pathogen has to be seen by the host MHC before an efficient immune response can occur

* Antigen from a pathogen has to be seen by the host MHC before an efficient immune response can occur

** There is therefore a constant evolutionary battle between the host and the pathogen

** There is therefore a constant evolutionary battle between the host and the pathogen