Breeding for improved soybean-Bradyrhizobia symbiosis for cool growing conditions in Central Europe

Background In recent years soybean (Glycine max L.) has gained significant attention in Europe due to its ability to produce high quality protein for human and animal consumption. Under the climatic conditions prevalent in Central Europe, low temperature is the major factor limiting soybean growth and symbiotic nitrogen fixation

Evidence for a LOS and a capsular polysaccharide in Capnocytophaga canimorsus

Capnocytophaga canimorsus is a dog's and cat's oral commensal which can cause fatal human infections upon bites or scratches. Infections mainly start with flu-like symptoms but can rapidly evolve in fatal septicaemia with a mortality as high as 40%. Here we present the discovery of a polysaccharide capsule (CPS) at the surface of C. canimorsus 5 (Cc5), a strain isolated from a fulminant septicaemia. We provide genetic and chemical data showing that this capsule is related to the lipooligosaccharide (LOS) and probably composed of the same polysaccharide units. A CPS was also found in nine out of nine other strains of C. canimorsus. In addition, the genomes of three of these strains, sequenced previously, contain genes similar to those encoding CPS biosynthesis in Cc5. Thus, the presence of a CPS is likely to be a common property of C. canimorsus. The CPS and not the LOS confers protection against the bactericidal effect of human serum and phagocytosis by macrophages. An antiserum raised against the capsule increased the killing of C. canimorsus by human serum thus showing that anti-capsule antibodies have a protective role. These findings provide a new major element in the understanding of the pathogenesis of C. canimorsus

New iron acquisition system in Bacteroidetes

Capnocytophaga canimorsus, a dog mouth commensal and a member of the Bacteroidetes phylum, causes rare but often fatal septicemia in humans that have been in contact with a dog. Here, we show that C. canimorsus strains isolated from human infections grow readily in heat-inactivated human serum and that this property depends on a typical polysaccharide utilization locus (PUL), namely, PUL3 in strain Cc5. PUL are a hallmark of Bacteroidetes, and they encode various products, including surface protein complexes that capture and process polysaccharides or glycoproteins. The archetype system is the Bacteroides thetaiotaomicron Sus system, devoted to starch utilization. Unexpectedly, PUL3 conferred the capacity to acquire iron from serotransferrin (STF), and this capacity required each of the seven encoded proteins, indicating that a whole Sus-like machinery is acting as an iron capture system (ICS), a new and unexpected function for Sus-like machinery. No siderophore could be detected in the culture supernatant of C. canimorsus, suggesting that the Sus-like machinery captures iron directly from transferrin, but this could not be formally demonstrated. The seven genes of the ICS were found in the genomes of several opportunistic pathogens from the Capnocytophaga and Prevotella genera, in different isolates of the severe poultry pathogen Riemerella anatipestifer, and in strains of Bacteroides fragilis and Odoribacter splanchnicus isolated from human infections. Thus, this study describes a new type of ICS that evolved in Bacteroidetes from a polysaccharide utilization system and most likely represents an important virulence factor in this group

Measuring the burden of infodemics : summary of the methods and results of the fifth WHO infodemic management conference

Background: An infodemic is excess information, including false or misleading information, that spreads in digital and physical environments during a public health emergency. The COVID-19 pandemic has been accompanied by an unprecedented global infodemic that has led to confusion about the benefits of medical and public health interventions, with substantial impact on risk-taking and health-seeking behaviors, eroding trust in health authorities and compromising the effectiveness of public health responses and policies. Standardized measures are needed to quantify the harmful impacts of the infodemic in a systematic and methodologically robust manner, as well as harmonizing highly divergent approaches currently explored for this purpose. This can serve as a foundation for a systematic, evidence-based approach to monitoring, identifying, and mitigating future infodemic harms in emergency preparedness and prevention. Objective: In this paper, we summarize the Fifth World Health Organization (WHO) Infodemic Management Conference structure, proceedings, outcomes, and proposed actions seeking to identify the interdisciplinary approaches and frameworks needed to enable the measurement of the burden of infodemics. Methods: An iterative human-centered design (HCD) approach and concept mapping were used to facilitate focused discussions and allow for the generation of actionable outcomes and recommendations. The discussions included 86 participants representing diverse scientific disciplines and health authorities from 28 countries across all WHO regions, along with observers from civil society and global public health–implementing partners. A thematic map capturing the concepts matching the key contributing factors to the public health burden of infodemics was used throughout the conference to frame and contextualize discussions. Five key areas for immediate action were identified. Results: The 5 key areas for the development of metrics to assess the burden of infodemics and associated interventions included (1) developing standardized definitions and ensuring the adoption thereof; (2) improving the map of concepts influencing the burden of infodemics; (3) conducting a review of evidence, tools, and data sources; (4) setting up a technical working group; and (5) addressing immediate priorities for postpandemic recovery and resilience building. The summary report consolidated group input toward a common vocabulary with standardized terms, concepts, study designs, measures, and tools to estimate the burden of infodemics and the effectiveness of infodemic management interventions. Conclusions: Standardizing measurement is the basis for documenting the burden of infodemics on health systems and population health during emergencies. Investment is needed into the development of practical, affordable, evidence-based, and systematic methods that are legally and ethically balanced for monitoring infodemics; generating diagnostics, infodemic insights, and recommendations; and developing interventions, action-oriented guidance, policies, support options, mechanisms, and tools for infodemic managers and emergency program managers.peer-reviewe

RANK and the regulation of lymph node and skin homeostasis

Le récepteur activant NF-κB (RANK), connu pour son rôle dans le remodelage osseux, est aussi impliqué dans le développement d’appendices de la peau et dans la biologie des cellules épithéliales, amenant la question de son rôle dans la peau et les follicules pileux (FP). Nous avons montré que les souris déficientes pour RANK ou son ligand (RANKL) ne peuvent initier une nouvelle phase du cycle pileux et qu’elles présentent une homéostasie de l’épiderme altérée. De plus, la surexpression de RANK dans les cellules souches (CS) des FP et l’administration de RANKL activent le cycle pileux et la croissance de l’épiderme. Les CS du FP expriment RANK et RANKL est activement transcrit par le FP en croissance mettant en évidence le rôle de RANK dans l’activation des CS pour l’entrée dans le cycle pileux. En plus de ces fonctions, RANK est requis pour le développement des ganglions lymphatiques (GL). Cette fonction est partagée avec le récepteur de la lymphotoxine LTβR qui est de plus impliqué dans le maintien de l’organisation du GL. Nous avons donc étudié la fonction de RANK dans le GL adulte en travaillant sur des souris surexprimant RANK dans le FP et développant une hyperplasie des GL drainant la peau. Ces GL présentent une proportion de cellules hématopoïétiques et stromales normale. Nous avons montré que RANKL dérivé de la peau induit la prolifération des cellules stromales ainsi que l’expression de chemokines et de molécules d’adhésion, déclenchant la croissance du GL. Ainsi nous avons décrit une nouvelle fonction de RANK dans le contrôle de la plasticité du GL et souligné l’importance des signaux dérivés des tissus pour l’homéostasie des organes lymphoïdes secondaires.The receptor activator of NF-κB (RANK) is known to control bone mass and development of the skin appendages. This, and its function in epithelial cell biology in general, incited us to investigate the role of RANK in skin and hair follicles (HFs). We show that mice deficient in RANK or RANK-ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. Transgenic mice overexpressing RANK in the HF and administration of recombinant RANKL activate the hair cycle and epidermal growth. RANK is expressed by HF stem cells and RANKL is actively transcribed by the growing HF supporting a role of RANK-activation of stem cells for hair cycle entry. In addition to its function in bone and skin, RANK is required for development of lymph nodes (LNs), a feature shared with lymphotoxin β receptor (LTβR). However, LTβR is further involved in the maintenance of LN organization, which had not been demonstrated for RANK. We therefore addressed the question of the function of RANK in LNs beyond development. For this, we took advantage of the transgenic mice overexpressing RANK in the HF, as they displayed a massive post-natal growth of skin-draining LNs. They displayed conserved proportions of hematopoietic and stromal cells, but an increase in the number of small B cell follicles. We showed that skin-derived RANKL induces LN stromal cell proliferation and expression of chemokines and adhesion molecules, resulting in the LN growth. This work highlighted an additional function for RANK-signaling in LNs, namely its control of LN plasticity, and underlines the importance of tissue-derived cues for secondary lymphoid organ homeostasis

RANK et la régulation de l homéostasie de la peau et du ganglion lymphatique

Le récepteur activant NF- B (RANK), connu pour son rôle dans le remodelage osseux, est aussi impliqué dans le développement d'appendices de la peau et dans la biologie des cellules épithéliales, amenant la question de son rôle dans la peau et les follicules pileux (FP). Nous avons montré que les souris déficientes pour RANK ou son ligand (RANKL) ne peuvent initier une nouvelle phase du cycle pileux et qu elles présentent une homéostasie de l'épiderme altérée. De plus, la surexpression de RANK dans les cellules souches (CS) des FP et l'administration de RANKL'activent le cycle pileux et la croissance de l'épiderme. Les CS du FP expriment RANK et RANKL'est activement transcrit par le FP en croissance mettant en évidence le rôle de RANK dans l'activation des CS pour l'entrée dans le cycle pileux. En plus de ces fonctions, RANK est requis pour le développement des ganglions lymphatiques (GL). Cette fonction est partagée avec le récepteur de la lymphotoxine LTbR qui est de plus impliqué dans le maintien de l'organisation du GL. Nous avons donc étudié la fonction de RANK dans le GL'adulte en travaillant sur des souris surexprimant RANK dans le FP et développant une hyperplasie des GL'drainant la peau. Ces GL'présentent une proportion de cellules hématopoïétiques et stromales normale. Nous avons montré que RANKL'dérivé de la peau induit la prolifération des cellules stromales ainsi que l'expression de chemokines et de molécules d'adhésion, déclenchant la croissance du GL. Ainsi nous avons décrit une nouvelle fonction de RANK dans le contrôle de la plasticité du GL'et souligné l'importance des signaux dérivés des tissus pour l'homéostasie des organes lymphoïdes secondaires.The receptor activator of NF- B (RANK) is known to control bone mass and development of the skin appendages. This, and its function in epithelial cell biology in general, incited us to investigate the role of RANK in skin and hair follicles (HFs). We show that mice de cient in RANK or RANK-ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. Transgenic mice overexpressing RANK in the HF and administration of recombinant RANKL activate the hair cycle and epidermal growth. RANK is expressed by HF stem cells and RANKL is actively transcribed by the growing HF supporting a role of RANK-activation of stem cells for hair cycle entry. In addition to its function in bone and skin, RANK is required for development of lymph nodes (LNs), a feature shared with lymphotoxin b receptor (LTbR). However, LTbR is further involved in the maintenance of LN organization, which had not been demonstrated for RANK. We therefore addressed the question of the function of RANK in LNs beyond development. For this, we took advantage of the transgenic mice overexpressing RANK in the HF, as they displayed a massive post-natal growth of skin-draining LNs. They displayed conserved proportions of hematopoietic and stromal cells, but an increase in the number of small B cell follicles. We showed that skin-derived RANKL induces LN stromal cell proliferation and expression of chemokines and adhesion molecules, resulting in the LN growth. This work highlighted an additional function for RANK-signaling in LNs, namely its control of LN plasticity, and underlines the importance of tissue-derived cues for secondary lymphoid organ homeostasis