Toll-Like Receptor 2–Deficient Mice Are Highly Susceptible to Streptococcus pneumoniae Meningitis because of Reduced Bacterial Clearing and Enhanced …

H Echchannaoui, K Frei, C Schnell… - The Journal of …, 2002 - academic.oup.com
H Echchannaoui, K Frei, C Schnell, SL Leib, W Zimmerli, R Landmann
The Journal of infectious diseases, 2002academic.oup.com
Abstract Toll-like receptor–2 (TLR2) mediates host responses to gram-positive bacterial wall
components. TLR2 function was investigated in a murine Streptococcus pneumoniae
meningitis model in wild-type (wt) and TLR2-deficient (TLR2−/−) mice. TLR2−/− mice
showed earlier time of death than wt mice (P<. 02). Plasma interleukin-6 levels and bacterial
numbers in blood and peripheral organs were similar for both strains. With ceftriaxone
therapy, none of the wt but 27% of the TLR2−/− mice died (P<. 04). Beyond 3 hours after …
Abstract
Toll-like receptor–2 (TLR2) mediates host responses to gram-positive bacterial wall components. TLR2 function was investigated in a murine Streptococcus pneumoniae meningitis model in wild-type (wt) and TLR2-deficient (TLR2−/−) mice. TLR2−/− mice showed earlier time of death than wt mice (P<.02). Plasma interleukin-6 levels and bacterial numbers in blood and peripheral organs were similar for both strains. With ceftriaxone therapy, none of the wt but 27% of the TLR2−/− mice died (P<.04). Beyond 3 hours after infection, TLR2−/− mice had higher bacterial loads in brain than did wt mice, as assessed with luciferase-tagged S. pneumoniae by means of a Xenogen-CCD (charge-coupled device) camera. After 24 h, tumor necrosis factor activity was higher in cerebrospinal fluid of TLR2−/− than wt mice (P<.05) and was related to increased blood-brain barrier permeability (Evans blue staining, P<.02). In conclusion, the lack of TLR2 was associated with earlier death from meningitis, which was not due to sepsis but to reduced brain bacterial clearing, followed by increased intrathecal inflammation
Oxford University Press