Synergism among oxidants, proteinases, phospholipases, microbial hemolysins, cationic proteins, and cytokines

Abstract

A striking similarity exists between the pathogenetic properties of group A streptococci and those of activated mammalian professional phagocytes (neutrophils, macrophages). Both types of cells are endowed by the ability to adhere to target cells; to elaborate oxidants, hydrolases, and membrane-active agents (hemolysins, phospholipases); and to freely invade tissues and destroy cells. From the evolutionary point of view, streptococci might justifiably be considered the forefathers of "modern" leukocytes. Our earlier findings that synergy between a streptococcal hemolysin (streptolysin S, SLS) and a streptococcal thiol-dependent proteinase and between cytotoxic antibodies+complement and streptokinase-activated plasmin readily killed tumor cells, led us to hypothesize that by analogy to the pathogenetic mechanisms of streptococci, the mechanisms of tissue destruction initiated by activated leukocytes in inflammatory sites, as well as in tissues undergoing episodes of ischemia and reperfusion, might also be the result of the synergistic effects among leukocyte-derived oxidants, phospholipases, proteinases, cytokines, and cationic proteins. The current report extends our previous synergy studies with endothelial cells to two additional cell types--monkey kidney epithelial cells and rat beating heart cells. Monolayers of 51Cr-labeled cells that had been treated by combinations of sublytic amounts of hydrogen peroxide (generated either by glucose oxidase, xanthine-xanthine oxidase, or by paraquat) and with sublytic amounts of a variety of membrane-active agents (streptolysin S, phospholipases A2 and C, lysophosphatides, histone, chlorhexidine) were killed in a synergistic manner (double synergy). Crystalline trypsin markedly enhanced cell killing by combinations of oxidant and the membrane-active agents (triple synergy). Injury to the cells was characterized by the appearance of large membrane blebs that detached from the cells and floated freely in the media, looking like lipid droplets. Cytotoxicity induced by the various combinations of agonists was depressed, to a large extent, by scavengers of hydrogen peroxide (catalase, dimethyl thiourea, and by Mn2+) but not by SOD or by deferoxamine. When cationic agents were employed together with hydrogen peroxide, polyanions (heparin, polyanethole sulfonate) were also found to inhibit cell killing. It is proposed that in order to effectively combat the deleterious toxic effects of leukocyte-derived agonists on cells and tissues, antagonistic "cocktails" comprised of cationized catalase, cationized SOD, dimethylthiourea, Mn(2+)+glycine, proteinase inhibitors, putative inhibitors of phospholipases, and polyanions might be concocted. The current literature on synergistic phenomena pertaining to mechanisms of cell and tissue injury in inflammation is selectively reviewed.

PADMA-28, a traditional tibetan herbal preparation inhibits the respiratory burst in human neutrophils, the killing of epithelial cells by mixtures of oxidants and pro-inflammatory agonists and peroxidation of lipids

“…Recent studies from our laboratories , Ginsburg and Misgav, 1992, Ginsburg and Mitra, 1993, Ginsburg, Kohen and Ligumsky, 1994, Ginsburg and Kohen, 1995a, have suggested that the killing of mammalian cells in infectious and in inflammatory sites might involve a well-orchestrated, synergistic 'cross-talk' among leukocyte-and microbial-derived oxidants, membrane-damaging agents and proteinases. While effective cell killing can be mediated by mixtures of oxidants and membrane-damaging agents, the release of significant amounts of membraneassociated lipids necessitates the additional presence of proteinases (Ginsburg and Mitra, 1993).…”

Is Histone a Solitary Vile Sepsis-Inducing Agent or Just "a Member of the Gang"?

“…This raises serious questions whether histones are agents with a special role in pathogenicity; perhaps they are "regular" damage associated molecular pattern (DAMP) mediators, or perhaps just markers of tissue damage [2]. Of note, a synergistic toxicity to human umbilical cord endothelial cells in culture by histones combined with several pro-inflammatory agonists such as oxidants and proteinases has already been studied in detail many years ago by our group [11][12][13][14][15]. In fact, the proposition that the sepsis syndrome is derived from synergistic phenomena was already debated and presented in the year 2000 during a symposium at the Rockefeller Institute [22]; it is unclear to us why this proposition hasn't been studied more closely since.…”

“…This should be especially being the case if they were to be combined with cocktails of anti-inflammatory agents as suggested previously [11][12][13][14]. These may be anti-oxidants, proteinase, elastase and PLA2 inhibitors, and anticytokines and perhaps even IV-IgG.…”

“…In vivo, histone administration was lethal, causing neutrophil margination, vacuolization of endothelium, intra-alveolar hemorrhage and macro-and microvascular thrombosis. Yet, if the histone theory of sepsis pathogenicity is considered, we should also remember that in addition to the action of toxic histones, activated neutrophils also secrete a plethora of other toxic and inflammatory agonists [3,[11][12][13][14][15]. These include superoxide (generated via NADPH oxidase), superoxide dismutase (dismutates superoxide to H 2 O 2 ), myeloperoxidase -H 2 O 2 generated HOCl, nitric oxide (NO) synthase (generates NO), the highly-toxic peroxynitrite, the polycation bactericidal LL-37, permeability inducing agents, cathelicidin, cationic elastase, gelatinase, several acid hydrolases, PLA2, as well as many cytokines and immune mediators (such as TNF-α, IL-1β, etc.).…”

Synergistic Aspects to Explain the Pathophysiology of Sepsis and Septic Shock-An Opinion

“…This microorganism generates membrane-damaging toxins such as streptolysins O and S, intracellular hemolysin, proteinase and spreading enzymes such hyaluronidase, 4 RNAses, DNAse, super antigens, anti-phagocytic M-protein, cross reactive antigens and highly phlogistic peptidoglycan. It may therefore be argued, that synergism among a multiplicity of similar agents might also be the main cause of damage inflicted also in septic shock [25,26]. Several publications, which may have direct relevance to septic shock, were published along the years [27][28][29][30][31][32][33][34][35][36][37][38][39][40].…”