suis [46]. The ability of SspA to induce cytokine secretion in macrophages was confirmed using a mutant of S. suis deficient in SspA expression. The secretion of IL-1β, TNF-α, and IL-6 was significantly less important when macrophages were stimulated with cells of SspA mutant compared to the stimulation with the parental strain. This strongly supports the contribution of SspA in

S. suis induced inflammatory response in macrophages. On the other hand, CCL5 secretion was found to be higher following stimulation with the SspA-deficient mutant compared to the parental strain. This result supports the capacity of the recombinant SspA protease to degrade CCL5. The fact that no decrease in CXCL8 secretion was observed following stimulation of macrophages

with the SspA-deficient mutant suggests that other cell surface components of S. suis, such as the cell wall [46], are likely to play a more important role in CXCL8 Nirogacestat in vivo secretion than the SspA protease. Conclusions In conclusion, this study bought evidence that the subtilisin-like protease SspA of S. suis may modulate the inflammation state find more associated with meningitis. It may either induce the secretion of important pro-inflammatory cytokines or, when present at high concentration, cause the degradation of selected cytokines, such as CCL5 and IL-6. Acknowledgements This study was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (NSERC). We wish to thank K. Vaillancourt for her technical assistance and M. Gottschalk for helpful discussions. References 1. Higgins R, Gottschalk M: Diseases of swine. Streptococal diseases 2006, 769–783. 2. Huang YT, Teng LJ, Ho SW, Hsueh PR: Streptococcus suis infection. J Microbiol Immunol Infect 2005,38(5):306–313.PubMed 3. Wertheim HF, Nghia HD, Taylor W, Schultsz C: Streptococcus suis : an emerging human pathogen. Clin Infect Dis 2009,48(5):617–625.PubMedCrossRef 4. Gottschalk M, Xu J, Lecours MP, Grenier D, Fittipaldi N, Segura M: Streptococcus suis Infections in Humans: What is the prognosis for Western

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