Functional consequences of cathepsin L deficiency in human lung epithelial cells.
Cathepsin L is a cysteine protease of the papain family. Lung epithelial cells play an important role in host defence. The aim of the present study was to investigate the functional role of cathepsin L in the human lung carcinoma cell line A549. Cathepsin L-deficient A549 clones were generated. They showed a significant lower proliferation and secreted 5- to 8-fold more IL-8 than the control cells. The production of IL-6, IL-18, and TGF-beta1/2 was not affected significantly. It was shown that the cells upregulate IL-8 transcription and that IL-8 in the culture supernatant is necessary for the containment of cellular proliferation. In conclusion, the data show that suppression of cathepsin L expression in A549 cells leads to a growth inhibition which is partially compensated by an upregulation of IL-8 production.
Wille
Aline
A
Institute of Immunology, Otto-von-Guericke University Magdeburg, Germany.
Heimburg
Anke
A
Gerber
Annegret
A
Reisenauer
Anita
A
Welte
Tobias
T
Bühling
Frank
F
D056668:Cathepsin L; D002403:Cathepsins / Q000172:deficiency / Q000502:physiology*; D002455:Cell Division; D003546:Cysteine Endopeptidases; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000201:enzymology*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000201:enzymology*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D016207:Cytokines; D016209:Interleukin-8; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L