GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

TableEdit

Jump to: navigation, search

PMID:24123819

You don't have sufficient rights on this wiki to edit tables. Perhaps you need to log in. Changes you make in the Table editor will not be saved back to the wiki

See Help for Help on this wiki. See the documentation for how to use the table editor

Citation

Hemarajata, P, Gao, C, Pflughoeft, KJ, Thomas, CM, Saulnier, DM, Spinler, JK and Versalovic, J (2013) Lactobacillus reuteri-specific immunoregulatory gene rsiR modulates histamine production and immunomodulation by Lactobacillus reuteri. J. Bacteriol. 195:5567-76

Abstract

Human microbiome-derived strains of Lactobacillus reuteri potently suppress proinflammatory cytokines like human tumor necrosis factor (TNF) by converting the amino acid l-histidine to the biogenic amine histamine. Histamine suppresses mitogen-activated protein (MAP) kinase activation and cytokine production by signaling via histamine receptor type 2 (H2) on myeloid cells. Investigations of the gene expression profiles of immunomodulatory L. reuteri ATCC PTA 6475 highlighted numerous genes that were highly expressed during the stationary phase of growth, when TNF suppression is most potent. One such gene was found to be a regulator of genes involved in histidine-histamine metabolism by this probiotic species. During the course of these studies, this gene was renamed the Lactobacillus reuteri-specific immunoregulatory (rsiR) gene. The rsiR gene is essential for human TNF suppression by L. reuteri and expression of the histidine decarboxylase (hdc) gene cluster on the L. reuteri chromosome. Inactivation of rsiR resulted in diminished TNF suppression in vitro and reduced anti-inflammatory effects in vivo in a trinitrobenzene sulfonic acid (TNBS)-induced mouse model of acute colitis. A L. reuteri strain lacking an intact rsiR gene was unable to suppress colitis and resulted in greater concentrations of serum amyloid A (SAA) in the bloodstream of affected animals. The PhdcAB promoter region targeted by rsiR was defined by reporter gene experiments. These studies support the presence of a regulatory gene, rsiR, which modulates the expression of a gene cluster known to mediate immunoregulation by probiotics at the transcriptional level. These findings may point the way toward new strategies for controlling gene expression in probiotics by dietary interventions or microbiome manipulation.

Links

PubMed PMC3889603 Online version:10.1128/JB.00261-13

Keywords

Animals; Artificial Gene Fusion; Colitis/chemically induced; Colitis/microbiology; Colitis/pathology; Cytokines/antagonists & inhibitors; Disease Models, Animal; Gene Expression Regulation, Bacterial; Genes, Reporter; Histamine/metabolism; Humans; Immunomodulation; Lactobacillus reuteri/genetics; Lactobacillus reuteri/immunology; Lactobacillus reuteri/isolation & purification; Lactobacillus reuteri/metabolism; Mice; Microbiota; Promoter Regions, Genetic; Transcription Factors/metabolism; Transcription, Genetic; Trinitrobenzenesulfonic Acid/toxicity

public



Cancel