title: Modulation of the endosomal and lysosomal distribution of cathepsins B, L and S in human monocytes/macrophages.
abstract: Endosomal and lysosomal fractions of human monocytes/macrophages prepared from buffy coats were analyzed for activities of cathepsins B, L and S, and expression of cathepsin proteins along with major histocompatibility complex class I and class II molecules under control and immunomodulatory conditions. While the total activity of cathepsins B, L, and S together remained unchanged in lysates of control cells during culture for 72 h, the subcellular distribution of cathepsin activities underwent a shift from a predominantly endosomal localization in freshly isolated cells to a lysosomal pattern after 72 h of culture. Interferon-gamma treatment for 72 h resulted in an upregulation of both major histocompatibility complex proteins and cathepsins with differential changes in cathepsin B, L and S activities in endosomes versus lysosomes. These changes suggest a remodeling of the endocytic machinery and imply different functions of cathepsins B, L and S during monocyte differentiation.
authors.affiliation: Institut für Pathologie, Universitätsklinikum Tübingen, Germany.
authors.forename: Heide
authors.initials: H
authors.lastname: Schmid
authors.forename: Ramona
authors.initials: R
authors.lastname: Sauerbrei
authors.forename: Gerold
authors.initials: G
authors.lastname: Schwarz
authors.forename: Ekkehard
authors.initials: E
authors.lastname: Weber
authors.forename: Hubert
authors.initials: H
authors.lastname: Kalbacher
authors.forename: Christoph
authors.initials: C
authors.lastname: Driessen
mesh_terms: D002401:Cathepsin B / Q000378:metabolism; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism*; D002454:Cell Differentiation; D002458:Cell Fractionation; D003546:Cysteine Endopeptidases; D011992:Endosomes / Q000201:enzymology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008247:Lysosomes / Q000201:enzymology*; D008264:Macrophages / Q000166:cytology / Q000201:enzymology*; D009000:Monocytes / Q000166:cytology / Q000201:enzymology*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D007371:Interferon-gamma; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L; C028217:cathepsin S