E-GEOD-45861 - Genome wide analysis of C57BL/6 mice and C57BL/6 TLR2-KO mice infected with European strain (P1/7) of Streptococcus suis
Released on 1 June 2013, last updated on 3 June 2014
Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST) 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR) 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2-/-) mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2-/- mice remained unaffected when compared to wild type (WT) mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain. Total RNA obtained from spleen of C57BL/6 mice or C57BL/6 TLR2-KO mice infected with Streptococcus suis strain P1/7. Four replicates in both groups.
transcription profiling by array
Claude Lachance, Jianguo Xu, Marcelo Gottschalk, Mariela Segura, Pehuén P Gerber