Streptococcus suis (S. suis) serotype 2 is an important pathogen of pigs causing various diseases, including meningitis, and how the pathogen cross the blood-brain barrier (BBB) is unclear. As an important virulence factor of S. suis, suilysin is shown to be helpful for the S. suis crossing the BBB. The aim of this study was to investigate the ability of suilysin produced by S. suis serotype 2 strain CVCC606 to induce the release of pro-inflammatory cytokine by rat brain microvascular endothelial cells (RBMVECs), first suilysin was purified by using different filtration steps, fractional precipitation with ammonium sulfate and Sephadex G-100 column chromatography. Then RBMVECs were exposed to suilysin, intracellular lactate dehydrogenase (LDH) and interleukin (IL)-6 release assays were employed, a time- and dose-dependent cytotoxicity of suilysin to RBMVECs was observed, and high levels of IL-6 production by RBMVECs could be induced with suilysin. Our findings suggest that cell injury and pro-inflammatory cytokine release of RBMVECs induced with suilysin is contribute to increase BBB permeability, and suilysin may be involved in the pathogenesis of meningitis caused by S. suis.
Suilysin, Streptococcus suis, purification, cell injury, cytokine, Microvascular endothelial cells
© The Author(s) 2014. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.