The role of the proteasome activator PA28 in MHC class I antigen processing

Mol Immunol. 2002 Oct;39(3-4):165-9. doi: 10.1016/s0161-5890(02)00099-8.


The proteasome system is the major source for the generation of viral antigens and tumor antigens presented by major histocompatibility complex class I (MHC class I) molecules. A specific feature of the proteasomal antigen processing machinery is that five of its components are inducible by IFN-gamma. Two of these are the alpha and beta subunits of the proteasome activator PA28. Our results show that PA28 selectively up-regulates the presentation of viral MHC class I epitopes and that down regulation PA28 in tumor cells results in impaired presentation of a human TRP2 tumor antigen.

Publication types

  • Review

MeSH terms

  • Animals
  • Antigen Presentation*
  • Antigens, Neoplasm / metabolism
  • Epitopes, T-Lymphocyte
  • Histocompatibility Antigens Class I / metabolism*
  • Humans
  • Muscle Proteins*
  • Proteasome Endopeptidase Complex
  • Proteins / physiology*
  • T-Lymphocytes, Cytotoxic / immunology


  • Antigens, Neoplasm
  • Epitopes, T-Lymphocyte
  • Histocompatibility Antigens Class I
  • Muscle Proteins
  • PSME1 protein, human
  • Proteins
  • PSME2 protein, human
  • Proteasome Endopeptidase Complex