cathepsin-g and Pleural-Effusion

In contrast to the excessively elevated immunochemically detectable concentrations of interleukin-6 (IL-6) in inflammatory exudates, the IL-6 bioactivities are significantly reduced, suggesting an inactivation of IL-6 at sites of inflammation. Since high amounts of proteases are released by invading neutrophils (PMN) in close temporal correlation to elevated IL-6 concentrations at sites of inflammation, this study focused on effects of the PMN-derived proteases elastase (NE), proteinase 3 (PR 3) and cathepsin G (Cat G) on the bioactivity and molecular integrity of IL-6. Here, we demonstrate that these enzymes play a crucial role in the initiation of the degradation and subsequent inactivation of IL-6 at sites of inflammation. Soluble IL-6 receptor subunits elicit a protective effect against the IL-6 inactivation by Cat G, only. Possible consequences of the proteolytical IL-6 inactivation for local inflammatory processes will be discussed.

Topics: Acute Disease; Ascitic Fluid; Cathepsin G; Cathepsins; Cell-Free System; Exudates and Transudates; Humans; Inflammation; Interleukin-6; Leukocyte Elastase; Myeloblastin; Neutrophils; Pleural Effusion; Receptors, Interleukin-6; Serine Endopeptidases; Solubility; Synovial Fluid