Related Experiment Video
Updated: Sep 27, 2026

Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells
Published on: October 22, 2012
An essential role for tripeptidyl peptidase in the generation of an MHC class I epitope
Ulrike Seifert1, Concepción Marañón, Ayelet Shmueli
1Institut für Biochemie-Charité, Medical Faculty of the Humboldt-University Berlin, Monbijoustr. 2, 10117 Berlin, Germany.
Most of the peptides presented by major histocompatibility complex (MHC) class I molecules require processing by proteasomes. Tripeptidyl peptidase II (TPPII), an aminopeptidase with endoproteolytic activity, may also have a role in antigen processing. Here, we analyzed the processing and presentation of the immunodominant human immunodeficiency virus epitope HIV-Nef(73-82) in human dendritic cells. We found that inhibition of proteasome activity did not impair Nef(73-82) epitope presentation. In contrast, specific inhibition of TPPII led to a reduction of Nef(73-82) epitope presentation. We propose that TPPII can act in combination with or independent of the proteasome system and can generate epitopes that evade generation by the proteasome-system.
Most of the peptides presented by major histocompatibility complex (MHC) class I molecules require processing by proteasomes. Tripeptidyl peptidase II (TPPII), an aminopeptidase with endoproteolytic activity, may also have a role in antigen processing. Here, we analyzed the processing and presentation of the immunodominant human immunodeficiency virus epitope HIV-Nef(73-82) in human dendritic cells. We found that inhibition of proteasome activity did not impair Nef(73-82) epitope presentation. In contrast, specific inhibition of TPPII led to a reduction of Nef(73-82) epitope presentation. We propose that TPPII can act in combination with or independent of the proteasome system and can generate epitopes that evade generation by the proteasome-system.
More Related Videos
Related Concept Videos
Antigen Processing Pathways
MHC Class I: Presenting Endogenous...
Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Mitochondrial Precursor Proteins
Most of the mitochondrial precursors...
Protein Digestion
Tagging and Fusion Proteins

