Role of nitric oxide and signaling pathways modulating the stimulatory effect of snake venom secretory PLA 2 S on non-opsonized zymosan phagocytosis by macrophages.

The phagocytic activity of macrophages activated with MT-II, a Lys-49 PLA ₂ homolog, and MT-III, an Asp-49 PLA ₂ , from Bothrops asper snake venom, was investigated in this study using a pharmacological approach. Stimulating thioglycollate-elicited macrophages with both venom components enhanced their ability to phagocytose non-opsonized zymosan particles. MT-II and MT-III-induced phagocytosis was drastically inhibited by pretreating cells with L-NAME, aminoguanidine or L-NIL, cNOS or iNOS inhibitors, or with ODQ (sGC inhibitor) or Rp-cGMPS (PKG inhibitor). These results indicate that the NO/sGC/GMP/PKG pathway plays an essential role in the β-glucan-mediated phagocytosis induced in macrophages by these venom-secretory PLA ₂ s.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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