ABSTRACT:

Porphyromonas gingivalis infected mice with an established P. gingivalis-specific inflammatory immune response were protected from developing alveolar bone resorption by therapeutic vaccination with a chimera (KAS2-A1) immunogen targeting the major virulence factors of the bacterium, the gingipain proteinases. Protection was characterised by an antigen-specific IgG1 isotype antibody and Th2 cell response. Adoptive transfer of KAS2-A1-specific IgG1 or IgG2 expressing B cells confirmed that IgG1-mediated protection. Furthermore, parenteral or intraoral administration of KAS2-A1-specific polyclonal antibodies protected against the development of P. gingivalis-induced bone resorption. The KAS2-A1-specific antibodies neutralised the gingipains by inhibiting: proteolytic activity, binding to host cells/proteins and co-aggregation with other periodontal bacteria. Combining key gingipain sequences into a chimera vaccine produced an effective therapeutic intervention that protected against P. gingivalis-induced periodontitis.

Link: http://www.nature.com/articles/npjvaccines201622

 

 

Le Carillon, où a eu lieu l'un des attaques du 13 novembre à Paris./Photo KCS

 

Peu après les attentats du 13 novembre à Paris qui ont fait 130 morts, le président du CNRS (Centre National de la Recherche Scientifique) Alain Fuchs avait appelé les scientifiques à faire des propositions pour offrir «sinon des solutions, du moins de nouvelles voies d'analyse et d'action».

Les projets devaient être envoyés au CNRS pour être analysés par un comité de pilotage composé de scientifiques.

Cet appel inédit à l'ensemble de la communauté française de l'enseignement supérieur et de la recherche «a été largement entendu», estime le CNRS qui vient de publier un premier bilan.

L'organisme public de recherche a reçu 202 projets à fin janvier. La date butoir pour recevoir des réponses est fixée au 3 mars. Après examen, il a décidé d'en financer 53, soit un peu plus du quart. Pour chaque projet, l'enveloppe varie entre 2.000 et 30.000 euros. Le budget total consacré à l'appel «attentats-recherche» dépassera les 600.000 euros, précise le CNRS.

http://www.ladepeche.fr/article/2016/02/28/2285842-chercheurs-cnrs-presentent-200-projets-lutter-contre-terrorisme.html

Parmi les projets retenus, figure celui présenté par LPS-BioSciences, pour la production d'antigènes purifiés de bactéries pouvant être utilisées dans le bioterrorisme, il vise à permettre d'améliorer les recherches et le développement de nouveaux tests de diagnostic ou de vaccins pour mieux résister à de telles menaces.

Pancreatic beta-cells limit autoimmune diabetes via an immunoregulatory antimicrobial peptide expressed under the influence of the gut microbiota

 

Antimicrobial peptides (AMPs) expressed by epithelial and immune cells are largely described for the defense against invading microorganisms. Recently, their immunomodulatory functions have been highlighted in various contexts. However how AMPs expressed by non-immune cells might influence autoimmune responses in peripheral tissues, such as the pancreas, is unknown. Here, we found that insulin-secreting β-cells produced the cathelicidin related antimicrobial peptide (CRAMP) and that this production was defective in non-obese diabetic (NOD) mice. CRAMP administrated to prediabetic NOD mice induced regulatory immune cells in the pancreatic islets, dampening the incidence of autoimmune diabetes. Additional investigation revealed that the production of CRAMP by β-cells was controlled by short-chain fatty acids produced by the gut microbiota. Accordingly, gut microbiota manipulations in NOD mice modulated CRAMP production and inflammation in the pancreatic islets, revealing that the gut microbiota directly shape the pancreatic immune environment and autoimmune diabetes development.

 

More info on:

http://www.sciencedirect.com/science/article/pii/S1074761315003027

http://www2.cnrs.fr/presse/communique/4161.htm

Santé

IMAGES. Bacteria living in our mouth.

 

 

http://www.sciencesetavenir.fr/sante/20160128.OBS3589/en-images-ces-bacteries-qui-vivent-dans-votre-bouche.html

 

LPS-BioSciences has been studying dental plaque to explore the various bacteria composing it.

By extracting and studying Lipid A structures in the dental plaque matrix, LPS-BioSciences is able to distinguish the bacterial species composing it.

The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has awarded seven research contracts to discover and characterize new adjuvants, or substances formulated as part of vaccines to enhance their protective ability.

“The goal of this research is to identify novel adjuvant candidates that safely and selectively boost vaccine-induced immune responses,” said NIAID Director Anthony S. Fauci, M.D. “Such adjuvants could be used to improve current vaccines, extend the vaccine supply or enhance vaccine efficacy in people with immature or weakened immune systems, such as infants and the elderly.”

Only three adjuvants — alum, AS04 and AS03 — are components of vaccines approved by the U.S. Food and Drug Administration for human use. Alum, which is composed of aluminum salts, is included in many U.S.-licensed vaccines, including those that protect against hepatitis B and pneumococcal infections. AS04, a combination of alum and an immune-stimulating lipid (fat), is included in the vaccine Cervarix, which prevents infection with the two human papillomavirus types that cause most cervical cancers.  The oil-in-water adjuvant AS03 is included in a vaccine for use in the event of an H5N1 bird flu epidemic.

NIAID adjuvant discovery contracts awarded in 2003 and 2009 identified adjuvants that trigger a small set of receptors of the innate, or inborn, immune system. The innate immune response helps shape adaptive, or acquired, immunity, which confers long-term protection from infection by specific pathogens. The new NIAID awards aim to expand the scope of adjuvant research by searching for any compound involved in the activation of the adaptive immune system.