Predictors of COVID-19 in an outpatient fever clinic.

Background: The objective of this study was to identify clinical risk factors for COVID-19 in a German outpatient fever clinic that allow distinction of SARS-CoV-2 infected patients from other patients with flu-like symptoms.

Methods: This is a retrospective, single-centre cohort study. Patients were included visiting the fever clinic from 4th of April 2020 to 15th of May 2020.

Gut Commensal-Induced IκBζ Expression in Dendritic Cells Influences the Th17 Response.

Intestinal commensal bacteria can have a large impact on the state of health and disease of the host. Regulation of Th17 cell development by gut commensals is known to contribute to their dichotomous role in promoting gut homeostasis and host defense, or development of autoimmune diseases. Yet, the underlying mechanisms remain to be fully elucidated.

DJ-1 (Park7) affects the gut microbiome, metabolites and the development of innate lymphoid cells (ILCs).

The proper communication between gut and brain is pivotal for the maintenance of health and, dysregulation of the gut-brain axis can lead to several clinical disorders. In Parkinson's disease (PD) 85% of all patients experienced constipation many years before showing any signs of motor phenotypes. For differential diagnosis and preventive treatment, there is an urgent need for the identification of biomarkers indicating early disease stages long before the disease phenotype manifests.

Wheat Consumption Aggravates Colitis in Mice via Amylase Trypsin Inhibitor-mediated Dysbiosis.

Background & Aims: Wheat has become the world's major staple and its consumption correlates with prevalence of noncommunicable disorders such as inflammatory bowel diseases. Amylase trypsin inhibitors (ATIs), a component of wheat, activate the intestine's innate immune response via toll-like receptor 4 (TLR4). We investigated the effects of wheat and ATIs on severity of colitis and fecal microbiota in mice.

Bacterial Immunogenicity Is Critical for the Induction of Regulatory B Cells in Suppressing Inflammatory Immune Responses.

B cells fulfill multifaceted functions that influence immune responses during health and disease. In autoimmune diseases, such as inflammatory bowel disease, multiple sclerosis and rheumatoid arthritis, depletion of functional B cells results in an aggravation of disease in humans and respective mouse models. This could be due to a lack of a pivotal B cell subpopulation: regulatory B cells (Bregs).

Weak Agonistic LPS Restores Intestinal Immune Homeostasis.

Generated by gram-negative bacteria, lipopolysaccharides (LPSs) are one of the most abundant and potent immunomodulatory substances present in the intestinal lumen. Interaction of agonistic LPS with the host myeloid-differentiation-2/Toll-like receptor 4 (MD-2/TLR4) receptor complex results in nuclear factor κB (NF-κB) activation, followed by the robust induction of pro-inflammatory immune responses. Here we have isolated LPS from a common gut commensal, Bacteroides vulgatus mpk (BVMPK), which provides only weak agonistic activity.

Flagellin hypervariable region determines symbiotic properties of commensal Escherichia coli strains.

Escherichia coli represents a classical intestinal gram-negative commensal. Despite this commensalism, different E. coli strains can mediate disparate immunogenic properties in a given host.

A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses.

The investigation of the immunogenic potential of commensal bacteria on the host immune system is one essential component when studying intestinal host-microbe interactions. It is well established that different commensals exhibit a different potential to stimulate the host intestinal immune system. Such investigations involve vertebrate animals, especially rodents.

: A Novel Invertebrate Model to Distinguish Intestinal Symbionts From Pathobionts.

Insects and mammals share evolutionary conserved innate immune responses to maintain intestinal homeostasis. We investigated whether the larvae of the greater wax moth may be used as an experimental organism to distinguish between symbiotic and pathobiotic , which are mammalian intestinal commensals. Oral application of the symbiont or pathobiont to resulted in clearly distinguishable innate immune responses that could be verified by analyzing similar innate immune components in mice and .

Genome Sequence of (Greater Wax Moth).

The larvae of the greater wax moth, , are pests of active beehives. In infection biology, these larvae are playing a more and more attractive role as an invertebrate host model. Here, we report on the first genome sequence of .

Proteome and phosphoproteome analysis of commensally induced dendritic cell maturation states.

Dendritic cells (DCs) can shape the immune system towards an inflammatory or tolerant state depending on the bacterial antigens and the environment they encounter. In this study we provide a proteomic catalogue of differentially expressed proteins between distinct DC maturation states, brought about by bacteria that differ in their endotoxicity. To achieve this, we have performed proteomics and phosphoproteomics on murine DC cultures.

Outer membrane vesicles blebbing contributes to B. vulgatus mpk-mediated immune response silencing.

The Gram negative intestinal symbiont Bacteroides vulgatus mpk is able to prevent from induction of colonic inflammation in Rag1 mice and promotes immune balance in Il2 mice. These inflammation-silencing effects are associated with B. vulgatus mpk-mediated induction of semi-mature dendritic cells, especially in the colonic lamina propria (cLP).

Phosphotransferase systems in Enterococcus faecalis OG1RF enhance anti-stress capacity in vitro and in vivo.

Phosphotransferase systems are common and essential in bacteria, which are in charge of sugar transportation and phosphorylation. However, phosphotransferase systems were found in recent years to be associated with environmental stress factors. This study investigated the role of the mannose/fructose/sorbose phosphotransferase systems in Enterococcus faecalis OG1RF in adaption to harsh environments by construction of pts mutants.

Microbiome and chronic inflammatory bowel diseases.

It is nowadays generally accepted that the microbiome is a central driver of chronic inflammatory bowel diseases based on observations from human patients as well as inflammatory rodent models. Many studies focussed on different aspects of microbiota and some scientists believe that a primary dis-balance results in a direct microbial induced inflammatory situation. It is also clear that the microbiome is influenced by environmental and genetic factors and is also tightly regulated by host defense molecules such as antimicrobial peptides (defensins et al.

Non-invasive detection and successful treatment of a Helicobacter pylori infection in a captive rhesus macaque.

Gastritis is a commonly diagnosed condition in non-human primates used in biomedical research. As in humans, Helicobacter pylori infection may cause gastritis. The following report presents a method of non-invasive detection and a successful treatment protocol for this common pathogen.

Symbiotic gut commensal bacteria act as host cathepsin S activity regulators.

Cathepsin S (CTSS) is a lysosomal protease whose activity regulation is important for MHC-II signaling and subsequent activation of CD4 T cell mediated immune responses. Dysregulation of its enzymatic activity or enhanced secretion into extracellular environments is associated with the induction or progression of several autoimmune diseases. Here we demonstrate that commensal intestinal bacteria influence secretion rates and intracellular activity of host CTSS and that symbiotic bacteria, i.

Extensive Mobilome-Driven Genome Diversification in Mouse Gut-Associated Bacteroides vulgatus mpk.

Like many other Bacteroides species, Bacteroides vulgatus strain mpk, a mouse fecal isolate which was shown to promote intestinal homeostasis, utilizes a variety of mobile elements for genome evolution. Based on sequences collected by Pacific Biosciences SMRT sequencing technology, we discuss the challenges of assembling and studying a bacterial genome of high plasticity. Additionally, we conducted comparative genomics comparing this commensal strain with the B.

Structure and function: Lipid A modifications in commensals and pathogens.

Lipopolysaccharides (LPS) of Gram negative bacteria are one of the most potent stimulators of the host innate immune system and LPS recognition is essential for the host organism to clear infections of invading bacterial pathogens. Here we review on the latest research on how LPS is sensed by host cells and how distinct LPS structures differentially modulate the strength of the host immune response. Much is known about host immunological reactions towards pathogens via recognition of their LPS, as well as strategies of pathogens to modulate their LPS structure in order to evade the immune system.

Molecular Mechanisms of Induction of Tolerant and Tolerogenic Intestinal Dendritic Cells in Mice.

How does the host manage to tolerate its own intestinal microbiota? A simple question leading to complicated answers. In order to maintain balanced immune responses in the intestine, the host immune system must tolerate commensal bacteria in the gut while it has to simultaneously keep the ability to fight pathogens and to clear infections. If this tender equilibrium is disturbed, severe chronic inflammatory reactions can result.

A novel approach for reliable detection of cathepsin S activities in mouse antigen presenting cells.

Cathepsin S (CTSS) is a eukaryotic protease mostly expressed in professional antigen presenting cells (APCs). Since CTSS activity regulation plays a role in the pathogenesis of various autoimmune diseases like multiple sclerosis, atherosclerosis, Sjögren's syndrome and psoriasis as well as in cancer progression, there is an ongoing interest in the reliable detection of cathepsin S activity. Various applications have been invented for specific detection of this enzyme.

Platelet-derived HMGB1 is a critical mediator of thrombosis.

Thrombosis and inflammation are intricately linked in several major clinical disorders, including disseminated intravascular coagulation and acute ischemic events. The damage-associated molecular pattern molecule high-mobility group box 1 (HMGB1) is upregulated by activated platelets in multiple inflammatory diseases; however, the contribution of platelet-derived HMGB1 in thrombosis remains unexplored. Here, we generated transgenic mice with platelet-specific ablation of HMGB1 and determined that platelet-derived HMGB1 is a critical mediator of thrombosis.