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A High Throughput MHC II Binding Assay for Quantitative Analysis of Peptide Epitopes
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Published on: March 25, 2014

Peptide loading in the endoplasmic reticulum accelerates trafficking of peptide:MHC class II complexes in B cells

S Morkowski1, G Raposo, H J Geuze

  • 1Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle, Wash., USA.

Journal of Biomedical Science
|February 6, 1999
PubMed

In a combination of biochemical and immunoelectron-microscopical approaches we studied intracellular trafficking and localization of the endoplasmic-reticulum (ER)-formed complexes of murine MHC class II molecule I-Ab and an antigenic peptide Ealpha52-68 covalently linked to its beta-chain. The association with the peptide in the ER leads to sharp acceleration of the intracellular trafficking of the complexes to the plasma membrane. Within the cells, Ealpha52-68:I-Ab complexes accumulate in the multivesicular MHC class II compartment (MIIC), but not in denser multilaminar or intermediate type MIICs. The changes in the trafficking of ER-formed complexes result solely from the presence of the tethered peptide, since wild-type class II molecules traffic similarly in bare lymphocyte syndrome cells and in wild-type antigen-presenting cells.

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