Trafficking of major histocompatibility complex class II molecules through intracellular compartments containing HLA-DM

Ninette F. Robbins, Craig Hammond, Lisa K. Denzin, Mary Pan, Peter Cresswell

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

The endosomal site(s) where MHC class II molecules become competent to bind antigenic peptide has not been completely characterized. We identified endocytic compartments through which newly synthesized MHC class II molecules move prior to their expression on the plasma membrane. The compartments co- sediment with lysosomes in the most dense regions of Percoll gradients. The appearance of proteolytic fragments of the invariant chain (I chain), namely leupeptin-induced proteins (LIPs) and class-II-associated invariant chain peptides (CLIP), in this region of the gradient suggests that the release of MHC class II molecules from I chain association occurs within these vesicles. The formation of SDS-stable αβ dimers indicated that MHC class II molecules contained within these compartments are receptive to peptide binding. A majority of the HLA-DM protein was found in the same region of the Percoll gradient, consistent with its established function in MHC class-II-restricted antigen presentation. Immunoelectron micrographs of dense-sedimenting compartments indicated that I chain, MHC class II, and DM molecules are contained within both multivesicular and multilamellar vesicles. The final stages of I chain dissociation from MHC class II molecules and DM-mediated peptide loading probably occur in these compartments.

Original languageEnglish (US)
Pages (from-to)13-23
Number of pages11
JournalHuman Immunology
Volume45
Issue number1
DOIs
StatePublished - Jan 1996
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Immunology and Allergy
  • Immunology

Fingerprint Dive into the research topics of 'Trafficking of major histocompatibility complex class II molecules through intracellular compartments containing HLA-DM'. Together they form a unique fingerprint.

  • Cite this