Bartonella quintana lipopolysaccharide is a natural antagonist of Toll-like receptor 4.

@article{Popa2007BartonellaQL,
  title={Bartonella quintana lipopolysaccharide is a natural antagonist of Toll-like receptor 4.},
  author={Calin D. Popa and Shahla Abdollahi-Roodsaz and Leo A B Joosten and Nozomi Takahashi and Tom Sprong and Giovanni Matera and Maria Carla Liberto and Alfredo Foc{\`a} and Marcel van Deuren and Bart Jan Kullberg and Wim B. van den Berg and Jos W M van der Meer and Mihai G Netea},
  journal={Infection and immunity},
  year={2007},
  volume={75 10},
  pages={4831-7}
}
Bartonella quintana is a gram-negative microorganism that causes trench fever and chronic bacteremia. B. quintana lipopolysaccharide (LPS) was unable to induce the production of proinflammatory cytokines in human monocytes. Interestingly, B. quintana LPS is a potent antagonist of Toll-like receptor 4 (TLR4), as it inhibited both mRNA transcription and the release of tumor necrosis factor alpha, interleukin 1beta (IL-1beta), and IL-6 by Escherichia coli LPS in human monocytes, at ratios ranging… CONTINUE READING