Porous nanoparticles with self-adjuvanting M2e-fusion protein and recombinant hemagglutinin provide strong and broadly protective immunity against influenza virus infections

Due to the high risk of an outbreak of pandemic influenza, the development of a broadly protective universal influenza vaccine is highly warranted. The design of such a vaccine has attracted attention and much focus has been given to nanoparticle-based influenza vaccines which can be administered intranasally. This is particularly interesting since, contrary to injectable vaccines, mucosal vaccines elicit local IgA and lung resident T cell immunity, which have been found to correlate with stronger protection in experimental models of influenza virus infections. Also, studies in human volunteers have indicated that pre-existing CD4(+) T cells correlate well to increased resistance against infection. We have previously developed a fusion protein with 3 copies of the ectodomain of matrix protein 2 (M2e), which is one of the most explored conserved influenza A virus antigens for a broadly protective vaccine known today. To improve the protective ability of the self-adjuvanting fusion protein, CTA1-3M2e-DD, we incorporated it into porous maltodextrin nanoparticles (NPLs). This proof-of-principle study demonstrates that the combined vaccine vector given intranasally enhanced immune protection against a live challenge infection and reduced the risk of virus transmission between immunized and unimmunized individuals. Most importantly, immune responses to NPLs that also contained recombinant hemagglutinin (HA) were strongly enhanced in a CTA1-enzyme dependentmanner and we achieved broadly protective immunity against a lethal infection with heterosubtypic influenza virus. Immune protection wasmediated by enhanced levels of lung resident CD4(+) T cells as well as anti-HA and -M2e serum IgG and local IgA antibodies

Multiple signaling pathways regulate the transcriptional activity of the orphan nuclear receptor NURR1

The orphan nuclear receptor nurr1 (NR4A2) is an essential transcription factor for the acquisition and maintenance of the phenotype of dopamine (DA)-synthesizing neurons in the mesencephalon. Although structurally related to ligand-regulated nuclear receptors, nurr1 is functionally atypical due to its inability to bind a cognate ligand and to activate transcription following canonical nuclear receptor (NR) rules. Importantly, the physiological stimuli that activate this NR and the signaling proteins that regulate its transcriptional activity in mesencephalic neurons are unknown. We used an affinity chromatography approach and CSM14.1 cells of mesencephalic origin to isolate and identify several proteins that interact directly with nurr1 and regulate its transcriptional activity. Notably, we demonstrate that the mitogen-activated protein kinases, ERK2 and ERK5, elevate, whereas LIM Kinase 1 inhibits nurr1 transcriptional activity. Furthermore, nurr1 recruits ERK5 to a NBRE-containing promoter and is a potential substrate for this kinase. We have identified amino acids in the A/B domain of nurr1 important for mediating the ERK5 activating effects on nurr1 transcriptional activity. Our results suggest that nurr1 acts as a point of convergence for multiple signaling pathways that likely play a critical role in differentiation and phenotypic expression of dopaminergic (DAergic) neurons

Partenaires d'interaction, gènes cibles et rôles potentiels du récepteur nucléaire orphelin Nurr1

Le récepteur nucléaire orphelin Nurr1, produit du gène NR4A2, régule de nombreux processus physiologiques comme la différenciation des neurones dopaminergiques, la mémorisation ou le métabolisme. Bien qu'appartenant à la superfamille des récepteurs nucléaires, Nurr1 est atypique car il ne peut lier de ligand et n'active pas la transcription des gènes suivant les règles classiques. De plus, les signaux physiologiques qui l'active et les voies de signalisation qui régulent son activité transcriptionnelle sont mal connus et peu d'informations concernent le programme transcriptionnel qu'il contrôle. Nous avons utilisé une approche par chromatographie d'affinité pour isoler des protéines interagissant avec Nurr1. Nous avons focalisé notre étude sur les conséquences de l'interaction de Nurr1 avec la kinase Erk5 et avec le récepteur des glucocorticoïdes, décrivant ainsi deux nouveaux modes de régulation de l'activité transcriptionnelle de Nurr1, l'un par phosphorylation et le second par hétérodimérisation. Nous montrons des interférences fonctionnelles positives par ces deux mécanismes suggérant des possibilités de modulation de l'activité de Nurr1 par ces deux partenaires d'interaction. Dans un deuxième temps nous avons recherché les gènes cibles de Nurr1 et avons identifié un gène dont les effets sont décrits tant au niveau cérébral (neurones dopaminergiques) que pancréatique. L'originalité d'un rôle potentiel de Nurr1 dans le pancréas nous a conduit à rechercher les stimuli permettant d'induire son expression dans les cellules beta pancréatiques et d'y étudier le programme transcriptionnel dirigé par Nurr1 afin de comprendre les conséquences physiologiques de l'expression de Nurr1 dans le pancréas. Ces résultats appuient le rôle de Nurr1 dans les métabolismes du glucose et des lipides, en lien avec la lipotoxicité observée lors du diabète de type II.LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Biliary differentiation and bile duct morphogenesis in development and disease.

The biliary tract consists of a network of intrahepatic and extrahepatic ducts that collect and drain the bile produced by hepatocytes to the gut. The bile ducts are lined by cholangiocytes, a specialized epithelial cell type that has a dual origin. Intrahepatic cholangiocytes derive from the liver precursor cells, whereas extrahepatic cholangiocytes are generated directly from the endoderm. In this review we discuss the mechanisms of cholangiocyte differentiation and bile duct morphogenesis, and describe how developing ducts interact with the hepatic artery. We also present an overview of the mechanisms of biliary dysgenesis in humans.Journal ArticleResearch Support, Non-U.S. Gov'tReviewinfo:eu-repo/semantics/publishe

Bioeliminable porous nanoparticles for protein delivery in airway mucosa

National audienc

Porous Maltodextrin-Based Nanoparticles: A Safe Delivery System for Nasal Vaccines

Vaccination faces limitations, and delivery systems additionally appear to have potential as tools to trigger protective immune responses against diseases. The nanoparticles studied are cationic maltodextrin-based nanoparticles with an anionic phospholipid core (NPL); they are a promising antigen delivery system, and their efficacy as drug vectors against complex diseases such as toxoplasmosis has already been demonstrated. Cationic compounds are generally described as toxic; therefore, it is of interest to evaluate the behavior of these NPL in vitro and in vivo. Here, we studied the in vitro toxicity (cytotoxicity and ROS induction in intestinal and airway epithelial cell lines) and the in vivo tolerability and genotoxicity of these nanoparticles administered by the nasal route to a rodent model. In vitro, these NPL were not cytotoxic and did not induce any ROS production. In vivo, even at very large doses (1000 times the expected human dose), no adverse effect and no genotoxicity were observed in lungs, stomach, colon, or liver. This study shows that these NPL can be safely used