Modulation of the endosomal and lysosomal distribution of cathepsins B, L and S in human monocytes/macrophages.
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.
Schmid
Heide
H
Institut für Pathologie, Universitätsklinikum Tübingen, Germany.
Sauerbrei
Ramona
R
Schwarz
Gerold
G
Weber
Ekkehard
E
Kalbacher
Hubert
H
Driessen
Christoph
C
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
D007371:Interferon-gamma; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L; C028217:cathepsin S