Dynamics of action of a Lys-49 and an Asp-49 PLAs on inflammasome NLRP3 activation in murine macrophages.

Phospholipases A (PLAs) are proteins found in snake venoms with hemolytic, anticoagulant, myotoxic, edematogenic, bactericidal and inflammatory actions. In Bothrops jararacussu snake venom were isolated a Lys49-PLA (BthTX-I) and an Asp49-PLA (BthTX-II) with myotoxic and inflammatory actions. Both PLAs can activate the NLRP3 inflammasome, an intracytoplasmic platform that recognizes molecules released when tissue is damaged liberating IL-1β that contributes to the inflammatory response observed in envenoming.

Crotalus neutralising factor and its role in human leukocyte modulation.

Crotalus neutralising factor (CNF) is an endogenous γ-type phospholipase A (PLA) inhibitor that inhibits the toxic action of crotoxin, a neurotoxin present in Crotalus durissus terrificus venom. However, its effects on the activation and modulation of immune cells, which play a major role in the development of inflammation, is not known. The objective of the present study was to assess the effects of CNF on human leukocyte modulation in vitro by analysing the following parameters: cell viability, phagocytic capacity, lipid droplet formation, reactive oxygen species production, nitric oxide production, p38 MAPK activation, and cytosolic PLA (cPLA) gene expression.