Structure and biological activities of a hexosamine-rich cell wall polysaccharide isolated from the probiotic Lactobacillus farciminis

Emmanuel Maes (1) , Irina Sadovskaya (2) , Mathilde Lévêque (3) , Elisabeth Elass-Rochard , Bruno Payré (4) , Thierry Grard (2) , Vassilia Theodorou (3) , Yann Guerardel (1) , Muriel Mercier-Bonin (3)

1 UGSF - Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576
2 BPA - Biochimie des Produits Aquatiques
3 ToxAlim-NGN - Neuro-Gastroentérologie & Nutrition
4 CMEAB - Centre de Microscopie Électronique Appliquée à la Biologie

Lactobacillus farciminis CIP 103136 is a bacterial strain with recognized probiotic properties. However, the mechanisms underlying such properties have only been partially elucidated. In this study, we isolated and purified a cell-wall associated polysaccharide (CWPS), and evaluated its biological role in vitro. The structure of CWPS and responses from stimulation of (i) human macrophage-like THP-1 cells, (ii) human embryonal kidney (HEK293) cells stably transfected with Toll-like receptors (TLR2 or TLR4) and (iii) human colonocyte-like T84 intestinal epithelial cells, upon exposure to CWPS were studied. The structure of the purified CWPS from L. farciminis CIP 103136 was analyzed by nuclear magnetic resonance (NMR), MALDI-TOF-TOF MS, and methylation analyses in its native form and following Smith degradation. It was shown to be a novel branched polysaccharide, composed of linear backbone of trisaccharide repeating units of: [6GlcpNAc14ManpNAc14GlcpNAc1] highly substituted with single residues of Glcp, Galp and GlcpNAc. Subsequently, the lack of pro- or anti-inflammatory properties of CWPS was established on macrophage-like THP-1 cells. In addition, CWPS failed to modulate cell signaling pathways dependent of TLR2 and TLR4 in transfected HEK-cells. Finally, in T84 cells, CWPS neither influenced intestinal barrier integrity under basal conditions nor prevented TNF-/IFN- cytokine-mediated epithelium impairment.

Mots clés: Probiotic; Cell wall polysaccharide; Intestinal barrier

Mots clés: Lactobacillus farciminis; Structure; Immunomodulation

Domaines: Biologie structurale [q-bio.BM]

Emmanuel Maes, Irina Sadovskaya, Mathilde Lévêque, Elisabeth Elass-Rochard, Bruno Payré, et al.. Structure and biological activities of a hexosamine-rich cell wall polysaccharide isolated from the probiotic Lactobacillus farciminis. Glycoconjugate Journal, 2019, 36 (1), pp.39-55. ⟨10.1007/s10719-018-09854-y⟩. ⟨hal-02371915⟩