The TIR Domain Containing Locus of Enterococcus faecalis Is Predominant among Urinary Tract Infection Isolates and Downregulates Host Inflammatory Response. (24th July 2014)

• Record Type: Journal Article
• Authors: Kraemer, Thomas Daniel; Quintanar Haro, Orlando Daniel; Domann, Eugen; Chakraborty, Trinad; Tchatalbachev, Svetlin
• Other Names: McClelland Michael Academic Editor.
• Is Part Of: International journal of microbiology. Volume 2014(2014)
• Publication Date: 2014-07-24
• Subjects: Microbiology -- Periodicals; Microbiology; Microbiology -- Periodicals; Electronic journals; Periodicals; 579
• DOI: 10.1155/2014/918143
• Languages: English
• ISSNs: 1687-918X

Abstract

Abstract : Based on Toll/interleukin-1 receptor (TIR) domain structure homology, we detected a previously uncharacterized gene encoding for a TIR domain containing protein (Tcp) in the genome of Enterococcus faecalis . We assigned this gene the name tcpF (as in Tcp of E. faecalis ). Screening of E. faecalis samples revealed that tcpF is more common in isolates from urinary tract infections (UTIs) than in human faecal flora. tcpF alleles showed moderate single nucleotide polymorphism (SNP) among UTI isolates. Infection of mouse RAW264.7 macrophages with a tcpF knock-out mutant led to elevated cytokine response compared to the isogenic wild type E. faecalis strain. In silico analysis predicted significant tertiary structure homology to the TIR domain of human TLR1 (TLR1-TIR). When transiently expressed in cultured eukaryotic cells, TcpF caused suppression of TLR2-dependent NF- κ B activation suggesting for TcpF a role as a factor in E. faecalis that benefits colonization by modulating the host's immune responses.