What Are Some Known Mechanisms of Antigen Processing Deficiencies in Cancer?
Several mechanisms have been identified through which cancer cells develop antigen processing deficiencies:
1. Proteasome Dysfunction: Mutations or altered expression of proteasome subunits can impair the generation of peptides needed for antigen presentation. 2. TAP Deficiency: Downregulation or mutations in TAP can result in reduced peptide transport into the endoplasmic reticulum, leading to insufficient peptide-MHC complex formation. 3. MHC Class I Downregulation: Many cancers exhibit reduced expression of MHC class I molecules, preventing the presentation of tumor antigens on the cell surface.
