The biosynthetic pathway of MHC class II but not class I molecules intersects the endocytic route

Cell. 1990 Apr 6;61(1):171-83. doi: 10.1016/0092-8674(90)90224-3.


We studied the intracellular traffic and subcellular distribution of MHC class I and class II antigens in comparison with a recycling surface glycoprotein, the transferrin receptor (Tfr), in the human lymphoblastoid cell line JY. No internalization was detectable for class I molecules. Class II molecules were internalized but did not recycle. In contrast, Tfr was found to internalize and recycle. The biosynthetic pathway of class II molecules differ from that of class I molecules in that it shows a delay (1-3 hr) in transport from trans-Golgi to cell surface: here it intersects the endocytic route. Immunoelectron microscopy using anti-MHC antibodies revealed the existence of vesicular structures that were intensely labeled for class II molecules. It is proposed that at this site combination of class II molecules with processed antigen could occur.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes
  • Cell Cycle
  • Cell Line
  • Cell Transformation, Viral
  • Endocytosis*
  • Genes, MHC Class I*
  • Genes, MHC Class II*
  • Herpesvirus 4, Human / genetics
  • Histocompatibility Antigens Class I / analysis*
  • Histocompatibility Antigens Class II / analysis*
  • Humans
  • Kinetics
  • Membrane Glycoproteins / biosynthesis*
  • Membrane Glycoproteins / metabolism
  • Microscopy, Electron
  • Organelles / ultrastructure


  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II
  • Membrane Glycoproteins