The effect of serine and thiol protease inhibitors on the chemiluminescence of human neutrophils in investigations In Vitro

Abstract

We have studied an indirect role of serine and thiol proteases in the activation of human neutrophils in vitro. Stimulation was evaluated using a chemiluminescence (CL) generation system. Receptor-dependent and receptor-independent stimuli were studied, e.g. opsonized zymosan, formyl-methionyl-leucyl-phenylalanine, platelet activating factor, phorbol myristate acetate, and calcium ionophore A23187. The serine protease inhibitors TPCK and TLCK, and thiol protease inhibitor PHMB, diminished the CL with different potencies and in a dose-dependent manner after treatment of cells with the various stimuli. Non-specific serine protease inhibitor, PMSF, and trypsin substrate TAME, showed a low inhibitory potency with respect to CL generation. Synthetic substrates for chymotrypsin (BTEE, ATEE) significantly inhibited CL with the various stimuli used with some differences in susceptibility to their inhibition. Specific chymotrypsin inhibitors diminished both the resting and activator-induced CL. We suggest that cell-bound chymotrypsin-like protease(s) is involved in the activation of signal transduction in human neutrophils after both receptor-dependent and receptor-independent stimulation.

Endothelial serpins—protectors of the vasculature?

“…The effects of serine proteinases, however, are not limited to their direct toxicity. They mediate antibody-dependent tumour cell cytolysis [13], augment the chemiluminescent response during neutrophil phagocytosis [14], modulate neutrophil superoxide production [15], prime platelets [16], and induce platelet aggregation and serotonin release [17].…”

Evaluation of TLR4 expression and chosen parameters of oxidative-antioxidative balance in young children with food allergy.

“…Recently, besides the well known pathogenic mechanisms contributing to allergic reaction, an important role of reactive oxygen species (ROS) is underlined too, among them are: superoxide anion, hydroxyl radical, singlet oxygen and peroxyl radical. The release of these compounds from neutrophils is accompanied by photon emission measured by chemiluminescence (CL) [18,19]. ROS created in the cell have influence on different structures and, can also activate NF-κB and numerous genes.…”

The influence of uremic high cystatin C concentration on neutrophil apoptosis and selected neutrophil functions isolated from healthy subjects

“…The CL was defined as the area under the light emission curve in the function of time (30 min). The area reflects the entire emission of light by the cells during the measurement [21]. …”