PA28 and the proteasome immunosubunits play a central and independent role in the production of MHC class I-binding peptides in vivo.

ABSTRACT: Proteasomes play a fundamental role in the processing of intracellular antigens into peptides that bind to MHC class I molecules for the presentation of CD8(+) T cells. Three IFN-γ-inducible catalytic proteasome (immuno)subunits as well as the IFN-γ-inducible proteasome activator PA28 dramatically accelerate the generation of a subset of MHC class I-presented antigenic peptides. To determine whether these IFN-γ-inducible proteasome components play a compounded role in antigen processing, we generated mice lacking both PA28 and immunosubunits β5i/LMP7 and β2i/MECL-1. Analyses of MHC class I cell-surface levels ex vivo demonstrated that PA28 deficiency reduced the production of MHC class I-binding peptides both in cells with and without immunosubunits, in the latter cells further decreasing

SUBMITTER: de Graaf N 

PROVIDER: S-EPMC3100532 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature