Different endocytic compartments are involved in the tight association of class II molecules with processed hen egg lysozyme and ribonuclease A in B cells

J. M. Escola, J. C. Grivel, P. Chavrier, J. P. Gorvel

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32 Citations (Scopus)


The processing of exogenous antigens and the association of peptides with class II molecules both occur within the endocytic pathway. 2A4 B lymphoma cells of the H-2(k) haplotype were grown in the presence or the absence of two different exogenous antigens (hen egg lysozyme and ribonuclease A) internalized by fluid-phase endocytosis. Using subcellular fractionation techniques, we demonstrate that, in the presence of hen egg lysozyme, newly synthesized SDS-stable class II molecules are detected in a dense endocytic compartment which does not have the characteristics of neither early and late endosomes nor lysosomes. In contrast, no SDS-stable class II molecules are observedbetween ribonuclease A and newly synthesized class II molecules. Interestingly, when class II molecules are analyzed at steady state, SDS-stable class II molecules induced by ribonuclease A are found in a compartment cosedimenting with late endosomes. These results suggest that the tight associations between ribonuclease A or hen egg lysozyme with class II molecules occur in distinct endocytic compartments and that these associations may depend on the sensitivity of antigens to proteolysis.

Original languageEnglish
Pages (from-to)2337-2345
Number of pages9
JournalJournal of Cell Science
Issue number6
Publication statusPublished - 1 Jan 1995



  • Antigens
  • B lymphocyte
  • Endocytosis
  • MHC class II molecules
  • Subcellular fractionation

ASJC Scopus subject areas

  • Cell Biology

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