Probing Peptidoglycan Synthesis in the Gut Commensal Akkermansia Muciniphila with Bioorthogonal Chemical Reporters.

Our gut microbiota directly influences human physiology in health and disease. The myriad of surface glycoconjugates in both the bacterial cell envelope and our gut cells dominate the microbiota-host interface and play a critical role in host response and microbiota homeostasis. Among these, peptidoglycan is the basic glycan polymer offering the cell rigidity and a basis on which many other glycoconjugates are anchored.

G protein peptidomimetics as allosteric modulators of the β-adrenergic receptor.

A series of G protein peptidomimetics were designed and synthesised based on the published X-ray crystal structure of the active state β-adrenergic receptor (βAR) in complex with the G protein (PDB 3SN6). We hypothesised that such peptidomimetics may function as allosteric modulators that target the intracellular G protein binding site of the βAR. Peptidomimetics were designed to mimic the 15 residue C-terminal α-helix of the G protein and were pre-organised in a helical conformation by (, + 4)-stapling using copper catalysed azide alkyne cycloaddition.

Getting a grip on glycans: A current overview of the metabolic oligosaccharide engineering toolbox.

This review discusses the advances in metabolic oligosaccharide engineering (MOE) from 2010 to 2016 with a focus on the structure, preparation, and reactivity of its chemical probes. A brief historical overview of MOE is followed by a comprehensive overview of the chemical probes currently available in the MOE molecular toolbox and the bioconjugation techniques they enable. The final part of the review focusses on the synthesis of a selection of probes and finishes with an outlook on recent and potential upcoming advances in the field of MOE.

Schistosomicidal activities of Lymnaea stagnalis haemocytes: the role of oxygen radicals.

Macrophage-like defence cells (haemocytes) of the pond snail Lymnaea stagnalis mediate cytotoxicity through reactive oxygen intermediates (ROIs). This activity is NADPH-oxidase dependent, as in mammalian phagocytes during the respiratory burst. In this study, mother sporocysts of schistosomes, the compatible Trichobilharzia ocellata and the incompatible Schistosoma mansoni evoke in vitro ROI activities (detected by luminol dependent chemiluminescence, LDCL) from L.

Phagocytic activity of macrophages and microglial cells during the course of acute and chronic relapsing experimental autoimmune encephalomyelitis.

The ED1 monoclonal antibody recognizes an antigen in lysosomal membranes of phagocytes. The expression of this antigen in cells increases during phagocytic activity. Here we describe the expression of ED1-immunoreactivity during the various stages of both acute (monophasic) and chronic relapsing experimental autoimmune encephalomyelitis (EAE) in the Lewis rat.

Separation of Lymnaea stagnalis hemocytes by density gradient centrifugation.

A chelating anti-clumping (alpha-C) buffer allowed blood cells (hemocytes) of a gastropod, Lymnaea stagnalis to be separated by discontinuous Percoll density gradient centrifugation. The hemocytes of L. stagnalis were separated into five fractions, having a density lower than 10, 20, 30, 40, and 50% Percoll, respectively.

NADPH-oxidase activity: the probable source of reactive oxygen intermediate generation in hemocytes of the gastropod Lymnaea stagnalis.

Macrophage-like defense cells (hemocytes) of the pond snail Lymnaea stagnalis generate reactive oxygen intermediates (ROIs) upon contact with non-self, following kinetics similar to those of ROI production by mammalian leukocytes during respiratory burst. In this study, several inhibitors of NADPH-oxidase, the key enzyme of the respiratory burst in mammalian phagocytes, were tested for their effect on oxidative activities [as demonstrated by nitroblue tetrazolium (NBT) reduction and luminol-dependent chemiluminescence (LDCL)] of phagocytosing snail hemocytes. In the presence of diphenylene iodonium, zymosan-stimulated hemocytes of L.

Reticulum cells in the ontogeny of nasal-associated lymphoid tissue (NALT) in the rat.

This study concerns the ontogeny of reticulum cells (RC) in the nasal-associated lymphoid tissue (NALT) of Wistar and Brown-Norway rats. A panel of monoclonal antibodies (mAb) directed against RC in peripheral lymphoid organs (antibodies ED10-ED15) was used, together with a recently developed antibody ED17, which recognizes macrophages and Langerhans cells. Early in embryogenesis, staining with common connective tissue markers, ED14 and ED15, was found.

The development and structure of mouse nasal-associated lymphoid tissue: an immuno- and enzyme-histochemical study.

This study deals with the structure and development of Nasal-Associated Lymphoid Tissue (NALT) in the mouse. NALT is present in the nasal cavity on both sides at the entrance of the pharyngeal duct. The lymphocytes are organized in B- and T-cell areas covered by an epithelium in which M-cells are present.

The in vivo antibody response in rat gut-associated lymphoid tissue (GALT) after immunization with bacterial polysaccharide antigen.

Gut mucosal immune responses to bacterial polysaccharide antigen in rats were investigated in vivo. Rats were immunized with pneumococcal polysaccharide type 3 (PPS-3) via different routes, i.e.

Peritoneal cell labelling: a study on the migration of macrophages and dendritic cells towards the gut.

In this study the migration of peritoneal cells was investigated by a fluorescence labelling technique. We found that peritoneal cells migrate to the subcapsular sinus and medulla of the parathymic lymph node (PTLN) and paratracheal lymph node (PTrLN). It was also observed that fluorescence labelled cells possibly granulocytes, macrophages and dendritic cells were found in the B cell follicles of Peyer patches and the dome area after intraperitoneal (ip) labelling.

Effect of mucosal and systemic immunization with pneumococcal polysaccharide type 3, 4 and 14 in the rat.

Four immunization routes were investigated to induce an immune response against three structurally different types of pneumoccoccal polysaccharide (PPS) in the rat. In particular, the contribution of the IgA isotype in these immune responses was studied. Six days after administration of PPS type 3, 4 or 14, the localization of specific antibody-containing cells (ACC) in different lymphoid tissues and the antibody titres in serum were studied.

The role of nasopharyngeal lymphoid tissue.

Nasal-associated lymphoid tissue (NALT), which comprises paired lymphoid organs in the nasopharynx of rodents, is the principal mucosal lymphoid tissue of the respiratory tract. As described in this review, NALT bears certain similarities to the Peyer's patches of the intestine but the two differ remarkably in morphology, lymphoid migration patterns and the binding properties of their high endothelial venules (HEV).

Lymphoid tissue in rat oral mucosa: structure and function.

Lymphocyte and macrophage/dendritic cell populations in the oral cavity of the rat were studied by immunohistochemistry. Furthermore, the reactivity of the oral mucosa towards antigen and its position in the mucosal immune system was investigated by staining antibody-forming cells and comparing serum and saliva antibody titres. Although numerous lymphocytes and non-lymphoid cells were present in the oral mucosa, organized lymphoid tissue could not be found.

Trichobilharzia ocellata in Lymnaea stagnalis: a flow cytometric approach to study its effects on hemocytes.

Flow cytometric analysis was performed on hemocytes in suspension derived from individual Lymnaea stagnalis. The distribution of cell sizes within the hemocyte population was comparable in all 40 specimens studied. The size distribution of circulating hemocytes is unimodal and continuous, with no discrete subpopulations, and is not affected by age or by infection with Trichobilharzia ocellata.

Ontogeny of reticulum cells in the rat intestine and their possible role in the development of the lymphoid microenvironment.

Ontogeny of reticulum cells (RC) in the rat intestine in relation to the development of the gut-associated lymphoid tissue (GALT) was studied using a panel of monoclonal antibodies (mab) directed against RC in peripheral lymphoid organs, ED10-ED15. The mab ED10 specific for RC in the spleen T cell area, recognized an epitope on gut RC, which cells seem to be involved in the influx and accumulation of lymphocytes in the lamina propria and in Peyer's patches (PP) and proximal colonic lymphoid tissue (PCLT). The mab ED11 which recognizes RC in the T cell area and B cell follicles of spleen, stained follicular dendritic cells (FEC) in the B cell area of the mesenteric lymph node (MLN), PP and PCLT.

Determination of the origin and nature of brain macrophages and microglial cells in mouse central nervous system, using non-radioactive in situ hybridization and immunoperoxidase techniques.

The origin and nature of brain macrophages and microglial cells in the mouse central nervous system (CNS) were investigated. First, the expression and localization of determinants recognized by the different monoclonal antibodies (mAbs) MOMA-1, Mac-1-alpha, and F4/80 (raised against cells of the mononuclear phagocyte system) were immunohistochemically studied in the developing and adult mouse brain. In order to clarify the origin of brain macrophages and microglial cells, we used bacteriophage lambda transgenic mice as donors for bone marrow transplantations in recipient mice of different ages.