@Article{ecn.2008.0128,
AUTHOR = {Giovanni Matera, Maria Carla Liberto, Leo A. B. Joosten, Maria Vinci, Angela Quirino, Maria Concetta Pulicari, Bart Jan Kullberg, Jos W. M. Van der Meer, Mihai G. Netea, Alfredo Focà},
TITLE = {The Janus face of <i>Bartonella quintana</i> recognition by Toll-like receptors (TLRs): a review},
JOURNAL = {European Cytokine Network},
VOLUME = {19},
YEAR = {2008},
NUMBER = {3},
PAGES = {113--118},
URL = {http://www.techscience.com/ECN/v19n3/65929},
ISSN = {1952-4005},
ABSTRACT = {<i>Bartonella quintana</i> (<i>B. quintana</i>) is a facultative, intracellular bacterium, which causes trench
fever, chronic bacteraemia and bacillary angiomatosis. Little is known about the recognition of <i>B. quintana</i> by the
innate immune system. In this review, we address the impact of Toll-like receptors (TLRs) on the recognition of
<i>B. quintana</i> and the activation of the host defense. When experimental models using human mononuclear cells,
transfected CHO cells, or TLR2<sup>-/-</sup> and TLR4<sup>-/-</sup> mice were used, differential effects of TLR2 and TLR4 have been
observed. <i>B. quintana</i> micro-organisms stimulated cytokine production through TLR2-mediated signals, whereas
no role for TLR4 in the recognition of this pathogen was observed. When single, water-phenol extraction was
performed, <i>B. quintana</i> LPS, stimulated cytokine production in a TLR2-dependent manner. However, when
double extraction was performed in order to generate highly purified LPS, <i>B. quintana</i> LPS entirely lost its
capacity to stimulate cytokines, demonstrating that non-LPS components of <i>B. quintana</i> are responsible for the
recognition through TLR2. Moreover, <i>B. quintana</i> LPS was shown to be a potent antagonist of Toll-like receptor
4 (TLR4). In conclusion, <i>B. quintana</i> is an inducer of cytokines through TLR2-, but not TLR4-, dependent
mechanisms. This stimulation is induced by bacterial components other than lipopolysaccharide. <i>B. quintana</i> LPS
is a naturally occurring antagonist of Toll-like receptor 4 (TLR4). In view of the role played by TLR4 in
inflammation, <i>B. quintana</i> LPS may be useful as an anti-TLR4 agent with therapeutic potential in both infections
and autoimmune inflammation.},
DOI = {10.1684/ecn.2008.0128}
}