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

J Biomed Sci. 1999 Jan;6(1):53-63. doi: 10.1007/BF02256424.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antigens, Differentiation, B-Lymphocyte / metabolism
  • Antigens, Surface / genetics
  • Antigens, Surface / metabolism*
  • B-Lymphocytes / metabolism*
  • Biological Transport
  • Cell Compartmentation
  • Cell Membrane / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Histocompatibility Antigens Class II / chemistry
  • Histocompatibility Antigens Class II / genetics
  • Histocompatibility Antigens Class II / metabolism*
  • Humans
  • Kinetics
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Immunoelectron
  • Peptide Fragments*
  • Peptides / metabolism*
  • Receptors, Antigen, T-Cell*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Severe Combined Immunodeficiency / metabolism
  • Subcellular Fractions

Substances

  • Antibodies, Monoclonal
  • Antigens, Differentiation, B-Lymphocyte
  • Antigens, Surface
  • Histocompatibility Antigens Class II
  • Peptide Fragments
  • Peptides
  • Receptors, Antigen, T-Cell
  • Recombinant Proteins
  • antigenic peptide Ealpha52-68
  • invariant chain