Department of Molecular Genetics and Microbiology; Department of Medicine, Division of Infectious Diseases and Immunology; Department of Molecular Genetics and Microbiology
Animals; Antigens, Bacterial; Cell Line; Dimerization; Escherichia coli; Female; Gene Expression Regulation; Humans; Interleukin-10; Mice; Mice, Inbred C57BL; Plague; Pore Forming Cytotoxic Proteins; Recombinant Proteins; *Signal Transduction; Toll-Like Receptor 2; Virulence; Yersinia pestis
Life Sciences | Medicine and Health Sciences
Pathogenic members of the Yersinia genus require the translocator protein LcrV for proper function of the type III secretion apparatus, which is crucial for virulence. LcrV has also been reported to play an independent immunosuppressive role via the induction of interleukin-10 (IL-10) through stimulation of Toll-like receptor 2 (TLR2). To investigate the LcrV-TLR2 interaction in vitro, His-tagged recombinant LcrV (rLcrV) from Yersinia pestis was cloned and expressed in Escherichia coli and purified through Ni-nitrilotriacetic acid column chromatography. High concentrations (5 microg/ml) of rLcrV stimulated TLR2 in vitro. Fractionation of rLcrV preparations via gel filtration revealed that only a minor component consisting of high-molecular-weight multimers or aggregates has TLR2 stimulating activity. Dimer and tetramer forms of rLcrV, which constitute the bulk of the material, do not have this activity. To investigate the potential role of LcrV/TLR2 in plague pathogenesis, we infected wild-type and TLR2(-/-) mice with virulent Y. pestis. No discernible difference between the two mouse strains in severity of disease or kinetics of survival after subcutaneous challenge was observed. IL-6, tumor necrosis factor, and IL-10 levels from spleen homogenates; bacterial load; and the extent of inflammation observed in organs from mice infected intravenously were also indistinguishable in both mouse strains. Taken together, our data indicate that the most abundant molecular species of Y. pestis LcrV do not efficiently activate TLR2-signaling and that TLR2-mediated immunomodulation is unlikely to play a significant role in plague.
DOI of Published Version
Infect Immun. 2007 Jul;75(7):3571-80. Epub 2007 Apr 16. Link to article on publisher's site
Infection and immunity
Pouliot, Kimberly Lea; Pan, Ning; Wang, Shixia; Lu, Shan; Lien, Egil; and Goguen, Jon D., "Evaluation of the role of LcrV-Toll-like receptor 2-mediated immunomodulation in the virulence of Yersinia pestis" (2007). Open Access Articles. 1264.