Lactococcus lactis supplement use

Food-grade lactic acid bacteria have been safely consumed by humans for centuries in fermented foods. Lactococcus lactis is widely used in the dairy industry as a starter, can be genetically engineered to efficiently produce a large variety of proteins. This feature has been recently exploited by scientists for the development of a new generation of vectors to deliver therapeutic proteins to the mucosal tissues. The successful Phase I clinical trial with a L. lactis strain secreting interleukin-10 for Crohn's disease has opened new horizons for the use of genetically engineered lactic acid bacteria as delivery vehicles.

Protection against Yersinia pseudotuberculosis infection conferred by a Lactococcus lactis mucosal delivery vector secreting LcrV.
Vaccine. 2009. Daniel C, Sebbane F, Poiret S, Goudercourt D, Dewulf J, Mullet C, Simonet M, Pot B. Laboratoire des Bactéries Lactiques et Immunité des Muqueuses, Institut Pasteur de Lille, Lille, France.
We evaluated the potential of a recombinant Lactococcus lactis strain secreting the Yersinia pseudotuberculosis low-calcium response V antigen for mucosal vaccination against Yersinia infections. We showed that the recombinant strain induced specific systemic and mucosal antibody and cellular immune responses after intranasal immunization and protected mice against both oral and systemic Yersenia pseudotuberculosis infections. This constitutes the first proof of principle for a novel anti-Yersinia mucosal vaccination strategy using recombinant lactic acid bacteria.

The cell surface of lactococcus lactis is covered by a protective polysaccharide pellicle.
J Biol Chem. 2010. Chapot-Chartier MP, Vinogradov E, Sadovskaya I, Furlan S, Bidnenko E, Courtin P, Pechoux C, Hols P, Dufrene YF, Kulakauskas S. INRA, France;
In Gram-positive bacteria, the functional role of surface polysaccharides (PS) that are not of capsular nature remains poorly understood. Here, we report the presence of a novel cell wall PS pellicle on the surface of Lactococcus lactis. Spontaneous PS-negative mutants were selected using semi-solid growth conditions and all mutations were mapped in a single chromosomal locus coding for PS biosynthesis. PS molecules were shown to be composed of hexasaccharide phosphate repeating units which are distinct from other bacterial PS. Using complementary atomic force and transmission electron microscopy techniques, we showed that the PS layer forms an outer pellicle surrounding the cell. Notably, we found that this cell wall layer confers a protective barrier against host phagocytosis by murine macrophages. Altogether, our results suggest that the PS pellicle could represent a new cell envelope structural component of Gram-positive bacteria.

Probiotic with lactococcus lactis bacteria supplements