Brucella beta 1,2 cyclic glucan is an activator of human and mouse dendritic cells

Bacterial cyclic glucans are glucose polymers that concentrate within the periplasm of alpha-proteobacteria. These molecules are necessary to maintain the homeostasis of the cell envelope by contributing to the osmolarity of Gram negative bacteria. Here, we demonstrate that Brucella beta 1,2 cyclic glucans are potent activators of human and mouse dendritic cells. Dendritic cells activation by Brucella beta 1,2 cyclic glucans requires TLR4, MyD88 and TRIF, but not CD14. The Brucella cyclic glucans showed neither toxicity nor immunogenicity compared to LPS and triggered antigen-specific CD8(+) T cell responses in vivo. These cyclic glucans also enhanced antigen-specific CD4(+) and CD8(+) T cell responses including cross-presentation by different human DC subsets. Brucella beta 1,2 cyclic glucans increased the memory CD4(+) T cell responses of blood mononuclear cells exposed to recombinant fusion proteins composed of anti-CD40 antibody and antigens from both hepatitis C virus and Mycobacterium tuberculosis. Thus cyclic glucans represent a new class of adjuvants, which might contribute to the development of effective antimicrobial therapies

Essais en laboratoire, d'un bioadditif (Aqua Kalgon +) destiné à l'élimination des sédiments organiques des plans d'eau

In-laboratory tests have been conducted in order to test the degradation activity of lacustrine organic sediments of a product made of a mineral phase and of lyophilized bacteria (Aquakalgon +). A monitoring of the water and sediment quality as well as measurements of the bacterial activity of populations which are part of the nitrogen cycle have shown no significant difference between pilot reactors and reactors treated with the bioadditive. / Des essais de laboratoire ont été réalisés pour tester l'activité de dégradation des sédiments lacustres organiques d'un produit comportant une phase minérale et des bactéries lyophilisées (Aquakalgon+). Un suivi de la qualité de l'eau et du sédiment ainsi que des mesures d'activité bactérienne de populations intervenant dans le cycle de l'azote n'ont montré aucune différence significative entre des réacteurs témoins et des réacteurs traités avec le bioadditif