Communications

2020

• C-ED/RES - Communication de type ED ou diffusion restreinte

  Peptides from proteins of Streptococcus thermophilus: an actor of its anti inflammatory properties?

  Séminaire de l'École Doctorale SIReNa, 13 février, Nancy, France

  Allouche, R., Hafeez, Z., Dary, A., Genay, M., Miclo, L.

  See the abstract

  Streptococcus thermophilus is widely used as a starter culture in the dairy industry and has been awarded generally recognized as safe status (GRAS) by the American Food and Drug Administration. Some strains of S. thermophilus display an anti-inflammatory activity in vitro (Junjua et al., 2016). Inflammation is a part of the regular host reaction to injury or infection caused by pathogens, damaged cells, irritants and allergens. However, the mechanism of action by which this bacterium modulates inflammatory response remains unclear. It has been shown that the hydrolysis of food proteins or endogenous proteins by some digestive proteases releases peptides with various biological activities. Such peptides can also be generated by the surface proteolytic system of Lactic Acid Bacteria (Hafeez et al., 2014) as S. thermophilus, which produces bioactive peptides from bovine caseins (Miclo et al., 2012). These peptides are inactive within the sequence of the parent protein and display their activity after a hydrolysis step. Thus, the assumption that peptides generated in the gastro-intestinal tract from hydrolysis of S. thermophilus surface or intracellular proteins could display an anti?inflammatory activity and contribute to the overall anti-inflammatory effect of the bacterium can be made. Therefore, it is interesting to explore the role of such peptides in the modulation of inflammation. In a first approach, this study aims to investigate the anti-inflammatory properties of hydrolysates genrated after hydrolysis by gastrointestinal enzymes of surface proteins of S. thermophilus. The method involves the recovery of bacterial surface polypeptides by shaving with pepsin. Supernatant obtained after shaving was analysed by RP-HPLC and showed the release of peptides. The next challenge constitutes evaluation in in vitro cell model of anti-inflammatory activity of the peptides obtained and the characterisation of these peptides by mass spectrometry. This study will lead to novel insights into the modulation of host inflammatory response through probable action of peptides obtained from S. thermophilus.

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