Proteasomes, TAP, and endoplasmic reticulum-associated aminopeptidase associated with antigen processing control CD4+ Th cell responses by regulating indirect presentation of MHC class II-restricted cytoplasmic antigens.

ABSTRACT: Cytoplasmic Ags derived from viruses, cytosolic bacteria, tumors, and allografts are presented to T cells by MHC class I or class II molecules. In the case of class II-restricted Ags, professional APCs acquire them during uptake of dead class II-negative cells and present them via a process called indirect presentation. It is generally assumed that the cytosolic Ag-processing machinery, which supplies peptides for presentation by class I molecules, plays very little role in indirect presentation of class II-restricted cytoplasmic Ags. Remarkably, upon testing this assumption, we found that proteasomes, TAP, and endoplasmic reticulum-associated aminopeptidase associated with Ag processing, but not tapasin, partially destroyed or removed cytoplasmic class II-restricted Ags, such that their i

SUBMITTER: Dragovic SM 

PROVIDER: S-EPMC3537507 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature