Role of crotoxin, a phospholipase A2 isolated from Crotalus durissus terrificus snake venom, on inflammatory and immune reactionsReportar como inadecuado




Role of crotoxin, a phospholipase A2 isolated from Crotalus durissus terrificus snake venom, on inflammatory and immune reactions - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Mediators of Inflammation - Volume 10 2001, Issue 3, Pages 125-133



Laboratory of Immunopathology, Institute Butantan, Av. Vital Brazil, 1500 São Paulo, São Paulo 05503–900, SP, Brazil

Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil

Laboratory of Immunochemistry, Institute Butantan, Av. Vital Brazil, 1500 São Paulo, São Paulo 05503–900, SP, Brazil



Copyright © 2001 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background: Crotoxin CTX is a potent neurotoxin from Crotalus durissus terrificus snake venom CdtV composed of two subunits: one without catalytic activity crotapotin, and a basic phospolipase A2. Recent data have demonstrated that CdtV or CTX inhibit some immune and inflammatory reactions.

Aim: The aim of this paper was to investigate the mechanisms involved in these impaired responses.

Materials and methods: Male Swiss mice were bled before and at different intervals of time after subcutaneous injection of CTX or bovine serum albumin BSA control animals. The effect of treatments on circulating leukocyte mobilisation and on serum levels of interleukin IL-6, IL-10, interferon IFN-γ and corticosterone were investigated. Spleen cells from treated animals were also stimulated in vitro with concanavalin A to evaluate the profile of IL-4, IL6, IL-10 or IFN-γ secretion. Cytokine levels were determined by immunoenzymatic assay and corticosterone levels by radioimmunoassay. To investigate the participation of endogenous corticosteroid on the effects evoked by CTX, animals were treated with metyrapone, an inhibitor of glucocorticoid synthesis, previous to CTX treatment.

Results: Marked alterations on peripheral leukocyte distribution, characterised by a drop in the number of lymphocytes and monocytes and an increase in the number of neutrophils, were observed after CTX injection. No such alteration was observed in BSAtreated animals. Increased levels of IL-6, IL-10 and corticosterone were also detected in CTX-injected animals. IFN- γ levels were not modified after treatments. In contrast, spleen cells obtained from CTX-treated animals and stimulated with concanavalin A secreted less IL-10 and IL-4 in comparison with cells obtained from control animals. Metyrapone pretreatment was effective only to reverse the neutrophilia observed after CTX administration.

Conclusions: Our results suggest that CTX may contribute to the deficient inflammatory and immune responses induced by crude CdtV.CTX induces endogenous mechanisms that are responsible, at least in part, for these impaired responses.





Autor: Diva F. Cardoso, Monica Lopes-Ferreira, Eliana L. Faquim-Mauro, Mahasti S. Macedo, and Sandra H. P. Farsky

Fuente: https://www.hindawi.com/



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