Bothrops snake venoms and their isolated toxins, an L-amino acid oxidase and a serine protease, modulate human complement system pathways

• Published in: Journal of Venomous Animals and Toxins including Tropical Diseases
• Main Authors: Lorena Rocha Ayres, Alex dos Reis Récio, Sandra Mara Burin, Juliana Campos Pereira, Andrea Casella Martins, Suely Vilela Sampaio, Fabíola Attié de Castro, Luciana Simon Pereira-Crott
• Format: Article in Journal/Newspaper
• Language: English
• Published: SciELO 2015
• Subjects: Bothrops jararacussu; Bothrops pirajai; Chemotaxis; Complement system; Kinetic microassay; L-amino acid oxidase; Serine protease; Snake venom; Arctic medicine. Tropical medicine; RC955-962; Toxicology. Poisons; RA1190-1270; Zoology; QL1-991; Arctic
• Online Access: https://doi.org/10.1186/s40409-015-0026-7; https://doaj.org/article/06dcb8c22d6d4814b76f492424477fc3

Background Activation of the complement system plays an important role in the regulation of immune and inflammatory reactions, and contributes to inflammatory responses triggered by envenomation provoked byBothrops snakes. The present study aimed to assess whether Bothrops jararacussuand Bothrops pirajai crude venoms and their isolated toxins, namely serine protease (BjussuSP-I) and L-amino acid oxidase (BpirLAAO-I), modulate human complement system pathways.Methods Lyophilized venom and toxin samples solubilized in phosphate buffered saline were diluted in appropriate buffers to evaluate their hemolytic activity on the alternative and classical pathways of the complement system. Venom- and toxin-treated normal human serum was added to the erythrocyte suspension, and the kinetic of hemolysis was measured spectrophotometrically at 700 nm. The kinetic 96-well microassay format was used for this purpose. We determined the t ½values (time required to lyse 50 % of target erythrocytes), which were employed to calculate the percentage of inhibition of the hemolytic activity promoted by each sample concentration. To confirm complement system activation, complement-dependent human neutrophil migration was examined using the Boyden chamber model.Results At the highest concentration tested (120 μg/mL), B. jararacussu and B. pirajai crude venoms inhibited the hemolytic activity of the classical pathway (65.3 % and 72.4 %, respectively) more strongly than they suppressed the hemolytic activity of the alternative pathway (14.2 and 13.6 %, respectively). BjussuSP-I (20 μg/mL) did not affect the hemolytic activity of the classical pathway, but slightly decreased the hemolytic activity of the alternative pathway (13.4 %). BpirLAAO-I (50 μg/mL) inhibited 24.3 and 12.4 % of the hemolytic activity of the classical and alternative pathways, respectively. Normal human serum treated with B. jararacussu and B. pirajai crude venoms induced human neutrophil migration at a level similar to that induced by zymosan-activated normal human ...