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Vectorial function of major histocompatibility complex class II in a human intestinal cell line
Author(s) -
L H A C Lopes,
Elaine Hughson,
Quentin M. Anstee,
Deborah A. O′Neil,
) Katz,
Benjamin M. Chain
Publication year - 1999
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.1999.00815.x
Subject(s) - microbiology and biotechnology , antigen processing , biology , antigen presentation , antigen , endosome , major histocompatibility complex , vesicle , epithelial polarity , human leukocyte antigen , cell , t cell , immunology , immune system , mhc class i , biochemistry , intracellular , membrane
This study explores the expression and the function of major histocompatibility complex class II in the intestinal epithelial cell line CaCo‐2, which has been widely used as a model for the human gastrointestinal epithelium. Human leucocyte antigen (HLA)‐DR expression on CaCo‐2 cells is induceable by interferon‐γ (IFN‐γ), but responsiveness to IFN‐γ is dependent on cell differentiation and IFN‐γ availability at the basolateral cell surface. HLA‐DR expression is concentrated in apical cytoplasmic vesicles and on the basolateral cell surface. Invariant chain is expressed in apical vesicles but is absent from the cell surface. Immunoprecipitation studies show a slow rate of dissociation of HLA‐DR from Ii. Double labelling shows some overlap between HLA‐DR expression and basolateral endosomal markers but no overlap with apical endosomal markers. Functional studies show processing and presentation of lysozyme endocytosed from the basolateral, but not apical surfaces. CaCo‐2 cells may provide a useful model with which to dissect the antigen‐processing pathways in polarized epithelial cells. The regulated access of antigens taken up from the gut lumen to the processing compartments may prevent overloading the immune system with antigens derived from normal gut contents.