Ruminococcin A, a New Lantibiotic Produced by a
            <i>Ruminococcus gnavu</i>
            s Strain Isolated from Human Feces

Dabard, J.; Bridonneau, Chantal; Phillipe, C.; Anglade, Patricia; Mollé, Daniel; Nardi, Michèle; Ladiré, M.; Girardin, HÃ©lÃ ̈ne; Marcille, F.; Gómez, Alberto Gómez; Fons, Michel

doi:10.1128/aem.67.9.4111-4118.2001

Cited by 149 publications

(122 citation statements)

References 31 publications

(21 reference statements)

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“…All procedures were carried out according to European guidelines for the care and use of laboratory animals and with permission 78 -122 of the French Veterinary Services. The following groups of rats (male, Fisher 344) were used: germ-free (GF); conventional (CV); GF inoculated with a fecal microbiota obtained from CV rats (Ino-CV); GF-inoculated with pure bacterial strains: C. paraputrificum (strain number: 217.59) (30) isolated from the intestinal contents of CV rats (Ino-Cp); B. thetaiotaomicron (strain number: BtII8) (Ino-Bt) (11) and R. gnavus (strain number: FRE1) (Ino-Rg) (9), isolated from the fecal contents of humans.…”

Section: Methodsmentioning

confidence: 99%

Microbiota matures colonic epithelium through a coordinated induction of cell cycle-related proteins in gnotobiotic rat

Cherbuy

Honvo-Houeto

Bruneau

et al. 2010

American Journal of Physiology-Gastrointestinal and Liver Physi

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Cherbuy C, Honvo-Houeto E, Bruneau A, Bridonneau C, Mayeur C, Duée PH, Langella P, Thomas M. Microbiota matures colonic epithelium through a coordinated induction of cell cycle-related proteins in gnotobiotic rat. Am J Physiol Gastrointest Liver Physiol 299: G348 -G357, 2010. First published May 13, 2010; doi:10.1152/ajpgi.00384.2009.-Previous studies have suggested that intestinal microbiota modulates colonic epithelium renewal. The objective of our work was to study the effects of microbiota on colonic epithelium structure and cell cycle-related proteins by using gnotobiotic rats. Colonic crypts and amount of cell cycle-related proteins were compared between germ-free (GF), conventional (CV), and conventionalized rats by histochemistry and Western blot. Ki67 and proliferating cell nuclear antigen (PCNA) were used as surrogates for proliferative cells; p21 cip1 and p27 kip1 were markers of cell cycle arrest; anti-and proapoptotic proteins, Bcl2 and Bax, respectively, were also studied. We observed 40% increase of the crypt proliferative area 2 days after inoculation of GF rats with a complex microbiota. This recruitment of proliferative cells may account for the 30% increase of crypt depth observed between CV and GF rats. The hyperproliferative boost induced by microbiota was compensated by a fourfold increase of p21 cip1 and p27 kip1 involved in cell cycle arrest and a 30% drop of antiapoptotic Bcl2 protein while Bax was unchanged. Inductions of p21 cip1 , p27 kip1 , and PCNA protein were not paralleled by an increase of the corresponding mRNA. We also showed that p21 cip1 induction by microbiota was partially restored by Bacteroides thetaiotaomicron, Ruminococcus gnavus, and Clostridium paraputrificum. Colonization of the colon by a complex microbiota increases the crypt depth of colon epithelium. This event takes place in conjunction with a multistep process: a hyperproliferative boost accompanied by compensatory events as induction of p21 cip1 and p27 kip1 and decrease of Bcl2.intestine; germ-free; PCNA; Bcl2; p21 cip1 ; p27 kip1 THE GASTROINTESTINAL TRACT of mammals is colonized by a community of microorganisms reaching levels as high as 10 11 bacteria/g of content in the colon. The intestinal microbiota includes more than 1,000 different species of bacteria belonging mainly to two divisions, the Firmicutes and the Bacteroidetes. Microbiota represents a large genomic repertoire as revealed by metagenomic approaches (12) and an efficacious organ to recover energy (33). Intestinal microbiota has coevolved with its host, exploiting mutualistic interactions (24). Thus the gut immune tolerance toward microbiota partly involves fine-tuned regulation of the transcription factor NF-B by commensal bacteria (19). Furthermore, microbiota induce expression of fucosylated cell surface glycans by mammalian gut epithelium (4, 29), which may be used as receptors for bacterial adhesins or as energy sources for the intestinal bacteria, especially in limited nutrient availability (45). Finally, our group has shown that in...

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Section: Methodsmentioning

confidence: 99%

Microbiota matures colonic epithelium through a coordinated induction of cell cycle-related proteins in gnotobiotic rat

Cherbuy

Honvo-Houeto

Bruneau

et al. 2010

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…As previously reported for some AMPs, including HD-5 (77,124) and some cathelicidins (212), it is interesting that two antibacterial substances produced by bacterial species in the intestinal microbiota, Peptostreptococcus sp. (325) and the R. gnavus E1 strain (78,126), require processing to be activated, after the proforms have been cleaved by trypsin.…”

Section: Barrier Effect Against Pathogensmentioning

confidence: 99%

The Front Line of Enteric Host Defense against Unwelcome Intrusion of Harmful Microorganisms: Mucins, Antimicrobial Peptides, and Microbiota

2006

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SUMMARY The intestinal tract is a complex ecosystem that combines resident microbiota and the cells of various phenotypes with complex metabolic activities that line the epithelial wall. The intestinal cells that make up the epithelium provide physical and chemical barriers that protect the host against the unwanted intrusion of microorganisms that hijack the cellular molecules and signaling pathways of the host and become pathogenic. Some of the organisms making up the intestinal microbiota also have microbicidal effects that contribute to the barrier against enteric pathogens. This review describes the two cell lineages present in the intestinal epithelium: the goblet cells and the Paneth cells, both of which play a pivotal role in the first line of enteric defense by producing mucus and antimicrobial peptides, respectively. We also analyze recent insights into the intestinal microbiota and the mechanisms by which some resident species act as a barrier to enteric pathogens. Moreover, this review examines whether the cells producing mucins or antimicrobial peptides and the resident microbiota act in partnership and whether they function individually and/or synergistically to provide the host with an effective front line of defense against harmful enteric pathogens.

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“…Third, production of microbicidal factors is a common case of interference competition among bacteria. Numerous bacteriocins produced by the intestinal microbiota are active against potential pathogens such as Listeria, Salmonella and Clostridium species (Dabard et al, 2001;Gong et al, 2010;Rea et al, 2010). Cuticular Streptomycetes bacteria are protecting the offspring of digger wasps from fungal pathogens by producing a complex cocktail of antibiotics (Kroiss et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Bacteria–bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance

et al. 2014

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Epithelial surfaces of most animals are colonized by diverse microbial communities. Although it is generally agreed that commensal bacteria can serve beneficial functions, the processes involved are poorly understood. Here we report that in the basal metazoan Hydra, ectodermal epithelial cells are covered with a multilayered glycocalyx that provides a habitat for a distinctive microbial community. Removing this epithelial microbiota results in lethal infection by the filamentous fungus Fusarium sp. Restoring the complex microbiota in gnotobiotic polyps prevents pathogen infection. Although mono-associations with distinct members of the microbiota fail to provide full protection, additive and synergistic interactions of commensal bacteria are contributing to full fungal resistance. Our results highlight the importance of resident microbiota diversity as a protective factor against pathogen infections. Besides revealing insights into the in vivo function of commensal microbes in Hydra, our findings indicate that interactions among commensal bacteria are essential to inhibit pathogen infection.

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Ruminococcin A, a New Lantibiotic Produced by a Ruminococcus gnavu s Strain Isolated from Human Feces

Cited by 149 publications

References 31 publications

Microbiota matures colonic epithelium through a coordinated induction of cell cycle-related proteins in gnotobiotic rat

Microbiota matures colonic epithelium through a coordinated induction of cell cycle-related proteins in gnotobiotic rat

The Front Line of Enteric Host Defense against Unwelcome Intrusion of Harmful Microorganisms: Mucins, Antimicrobial Peptides, and Microbiota

Bacteria–bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance

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