Accessible Unlicensed Requires Authentication Published by De Gruyter June 1, 2005

Modulation of the Endosomal and Lysosomal Distribution of Cathepsins B, L and S in Human Monocytes/Macrophages

H. Schmid, R. Sauerbrei, G. Schwarz, E. Weber, H. Kalbacher and C. Driessen
From the journal


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. Interferonγ 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.

Published Online: 2005-06-01
Published in Print: 2002-08-27

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