Autoimmunity
Step 7 of 7. The T-cell receptor on the T-cell surface can recognise many thousands of different peptides.
Autoimmunity is believed to occur when a T-cell that is selected and raised to fight infection then inadvertently recognises a peptide derived from a ‘self’ protein. The net result is that these T-cells then turn on our own tissues.
All autoimmune diseases are genetically linked to certain MHC molecules. MHC molecules are designed to present peptides to T-cells. We therefore believe that rogue T-cells are the root cause of all autoimmunity.