TY - JOUR T1 - Identification of an anti-inflammatory protein from <em>Faecalibacterium prausnitzii</em>, a commensal bacterium deficient in Crohn’s disease JF - Gut JO - Gut SP - 415 LP - 425 DO - 10.1136/gutjnl-2014-307649 VL - 65 IS - 3 AU - E Quévrain AU - M A Maubert AU - C Michon AU - F Chain AU - R Marquant AU - J Tailhades AU - S Miquel AU - L Carlier AU - L G Bermúdez-Humarán AU - B Pigneur AU - O Lequin AU - P Kharrat AU - G Thomas AU - D Rainteau AU - C Aubry AU - N Breyner AU - C Afonso AU - S Lavielle AU - J-P Grill AU - G Chassaing AU - J M Chatel AU - G Trugnan AU - R Xavier AU - P Langella AU - H Sokol AU - P Seksik Y1 - 2016/03/01 UR - http://gut.bmj.com/content/65/3/415.abstract N2 - Background Crohn’s disease (CD)-associated dysbiosis is characterised by a loss of Faecalibacterium prausnitzii, whose culture supernatant exerts an anti-inflammatory effect both in vitro and in vivo. However, the chemical nature of the anti-inflammatory compounds has not yet been determined.Methods Peptidomic analysis using mass spectrometry was applied to F. prausnitzii supernatant. Anti-inflammatory effects of identified peptides were tested in vitro directly on intestinal epithelial cell lines and on cell lines transfected with a plasmid construction coding for the candidate protein encompassing these peptides. In vivo, the cDNA of the candidate protein was delivered to the gut by recombinant lactic acid bacteria to prevent dinitrobenzene sulfonic acid (DNBS)-colitis in mice.Results The seven peptides, identified in the F. prausnitzii culture supernatants, derived from a single microbial anti-inflammatory molecule (MAM), a protein of 15 kDa, and comprising 53% of non-polar residues. This last feature prevented the direct characterisation of the putative anti-inflammatory activity of MAM-derived peptides. Transfection of MAM cDNA in epithelial cells led to a significant decrease in the activation of the nuclear factor (NF)-κB pathway with a dose-dependent effect. Finally, the use of a food-grade bacterium, Lactococcus lactis, delivering a plasmid encoding MAM was able to alleviate DNBS-induced colitis in mice.Conclusions A 15 kDa protein with anti-inflammatory properties is produced by F. prausnitzii, a commensal bacterium involved in CD pathogenesis. This protein is able to inhibit the NF-κB pathway in intestinal epithelial cells and to prevent colitis in an animal model. ER -