DR SIMON POWIS

MHC CLASS 1 PRESENTATION OF PEPTIDES TO CD8 T CELLS (peptides presented are derived from intracellular enviroment)

no longer required cytoplasmic proteins undergo ubiquitisation in the proteasome and get chopped up/cleaved into amino acids/peptides where they travel to the endoplasmic reticulum. MHC class 1 molecules then bind the peptides go through the golgi apparatus and present themselves on the surface of the cell

MHC CLASS 2 PRESENTATION OF PEPTIDES TO CD4 T CELLS (peptides presented are derived from extracellular environment)

MHC class 2 molecule produced in the ER and is pushed out into endosomal compartments before exiting the cell where they encounter pathogens that have been taken up extracellularly by the cell, here it is able to bind with peptide fragments before emerging at the cell surface to be seen by CD4 T cells