title: Granulocyte-macrophage colony-stimulating factor elevates invariant chain expression in immature myelomonocytic cell lines.
abstract: Invariant chain (Ii) plays an important role in major histocompatibility complex (MHC) class II antigen processing and presentation and is constitutively synthesized in B lymphocytes, in macrophages, dendritic cells and in some epithelial cells. It has been shown that interferon-gamma, tumour necrosis factor-alpha and interleukin-4 co-regulate Ii and MHC class II expression in various cell types. We describe here a novel regulation of Ii expression in macrophages. Treatment of the premature monocytic cell lines WEHI 265.1, M1 and WEHI-3B with recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) strongly enhances Ii expression while class II expression is not induced. In contrast, GM-CSF did not enhance Ii in mature macrophage cell lines. The increase of Ii expression in WEHI 265.1 cells takes several days. This long induction time, and a difference in activity between GM-CSF-conditioned medium and GM-CSF, together suggest that GM-CSF stimulates WEHI 265.1 cells to secrete a factor that modulates Ii expression. These results may imply a class II-independent function of Ii, which we discuss in this paper.
authors.affiliation: Division of Immunobiology, University of Bonn, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Klagge
authors.forename: U
authors.initials: U
authors.lastname: Kopp
authors.forename: N
authors.initials: N
authors.lastname: Koch
mesh_terms: D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis* / Q000235:genetics; D017077:Culture Media, Conditioned; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis* / Q000235:genetics; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000276:immunology
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D017077:Culture Media, Conditioned; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; C045084:invariant chain; D016178:Granulocyte-Macrophage Colony-Stimulating Factor