The Secretion of the Third Component of Complement (C3) by Human Polymorphonuclear Leucocytes from both Normal and Systemic Lupus Erythematosus Cases

Abstract

Recently, murine peritoneal exudate polymorphonuclear leucocytes (PMNs) have been proved to secrete complement C3. In this report we show the secretion of C3 by normal human blood PMNs. ELISA assay was used to detect secreted C3 in culture supernatants of PMNs, while immunoperoxidase staining was used for intracellular C3 detection. 12-o-tetradecanoyl phorbol 13 acetate (TPA) had a flushing effect on C3 secretion by PMNs but not macrophages, suggesting a special C3 storing capability in PMNs. Dioctanoyl glycerol, mezerein and calcium ionophore A23187 caused the same marked increase in C3 secretion by PMNs. This suggests the contribution of protein kinase C and the calmodulin pathway in the mechanism of C3 secretion, similar to murine peritoneal exudate PMNs. In some cases of systemic lupus erythematosus, C3 secretion by blood PMNs was increased but no similar response to TPA could be detected.

Role for Complement in Development ofHelicobacter-Induced Gastritis in Interleukin-10-Deficient Mice

“…A sandwich enzyme-linked immunosorbent assay (ELISA) was used to quantify C3 in mouse sera (13). Briefly, 96-well microtiter plates were coated with immunoglobulin G anti-mouse C3 (1:3000) (Cappel), washed with PBS, and incubated for 2 h at 37°C with serial dilutions of mouse sera.…”

Production of complement components by cells of the immune system

“…Stimulated PMNs were reported to secrete C3 with an intact thioester and it was speculated that the PMN-derived proteases, which are also released locally, can subsequently activate this newly secreted C3 [35,36]. Neutrophils not only store C3 but also FP, the only complement regulator that enhances complement activation, which can be secreted upon stimulation [30,35,37].…”

Plasma Complement C5 Protects Endothelial Cells from Polymorphonuclear Neutrophil-Derived, H2O2-Mediated Cytotoxicity

“…Many authors suggest that the complement system plays an important role in tissue damage [9,12,13,15,16,[27][28][29][30] and more specifically in endothelial cell damage [15,30]. Results of this present paper suggest that the synergistic action of FIG.…”