Role ofToll-Like Receptor 4 in Gram-Positive and Gram-Negative Pneumonia inMice

• DOI: 10.1128/iai.72.2.788-794.2004
• Publication Date: 2004-01-24T23:46:23Z
• Authors: Judith Branger; Sylvia Knapp; Sebastiaan Weijer; Jaklien C. Leemans; Jennie M. Pater; Peter Speelman; Sandrine Florquin; Tom van der Poll
• Keywords: Bacterial pneumonia; Klebsiella pneumonia; Gram-Negative Bacteria; Respiratory tract

ABSTRACT To determine the role of Toll-like receptor 4 (TLR4) in immune response to pneumonia, C3H/HeJ mice (which display a mutant nonfunctional TLR4) and C3H/HeN wild-type were intranasally infected with either Streptococcus pneumoniae (a common gram-positive respiratory pathogen) or Klebsiella gram-negative pathogen). In cases pneumococcal TLR4 showed reduced survival only after infection low-level bacterial doses, which was associated higher burden their lungs 48 h postinfection. demonstrated shortened low- high-level dose together an enhanced outgrowth lungs. These data suggest that contributes protective both pneumonia its is more important tract caused by latter (gram-negative) pathogen.