Search

Disseminated neoplasia (DN) is a form of cancer in bivalve molluscs that can be transmissible between individuals and in some cases across species. Neoplastic cells are highly proliferative, and infection is usually lethal. Commercially valuable bivalve species (mussels, cockles, softshell clams, and oysters) are affected by outbreaks of DN, making disease diagnosis and mitigation an important issue in ecological restoration efforts and aquaculture. Basket cockles (Clinocardiwn nuttallii) are native to the North American Pacific coast from California to Alaska. Recent concern from some Coast Salish Tribes regarding an observed long-term decline in basket cockle populations in Puget Sound. WA has increased interest in monitoring efforts and subsequent collection for aquarium-reared broodstock. Disseminated neoplasia was detected in Puget Sound basket cockle populations, delaying aquaculture efforts so that potential broodstock could be assessed for the presence of DN. This study details a minimally invasive, inexpensive, nonlethal method for high-throughput screening for DN in adult basket cockles. The hemolymph smear screening method to diagnose DN in C. nuttallii can be applied at field sites at low financial cost. Results of the hemolymph smear technique were validated against whole tissue histology, the standard method for DN diagnosis. Due to the similar cellular morphologies of DN in different bivalve species, it is proposed that hemolymph histology can likely be applied for diagnosing DN in other bivalves. KEY WORDS: disseminated neoplasia, Cltnocardiwn nuttallii, disease screening, tissue histology, basket cockle, INTRODUCTION Diverse bivalve species worldwide are susceptible to disseminated neoplasia (DN), a disease in which cancerous cells proliferate in the hemolymph--the blood-like fluid in molluscs containing a mixture of nutrients, [...]

Cell suspension fluidics, such as flow cytometry (FCS) and fluorescence-activated cell sorting (FACS), facilitates the identification and precise separation of individual cells based on phenotype. Since its introduction, flow cytometry has been used to analyze cell types and cellular processes in diverse non-vertebrate taxa, including cnidarians, molluscs, and arthropods. Ctenophores, which diverged very early from the metazoan stem lineage, have emerged as an informative clade for the study of metazoan cell type evolution. We present standardized methodologies for flow cytometry-mediated identification and analyses of cells from the model ctenophore Mnemiopsis leidyi that can also be applied to isolate targeted cell populations. Here we focus on the identification and isolation of ctenophore phagocytes. Implementing flow cytometry methods in ctenophores allows for fine scale analyses of fundamental cellular processes conserved broadly across animals, as well as potentially revealing novel cellular phenotypes and behaviors restricted to the ctenophore lineage.

Abstract Super‐resolution optical imaging tools are crucial in microbiology to understand the complex structures and behavior of microorganisms such as bacteria, fungi, and viruses. However, the capabilities of these tools, particularly when it comes to imaging pathogens and infected tissues, remain limited. MicroMagnify (µMagnify) is developed, a nanoscale multiplexed imaging method for pathogens and infected tissues that are derived from an expansion microscopy technique with a universal biomolecular anchor. The combination of heat denaturation and enzyme cocktails essential is found for robust cell wall digestion and expansion of microbial cells and infected tissues without distortion. µMagnify efficiently retains biomolecules suitable for high‐plex fluorescence imaging with nanoscale precision. It demonstrates up to eightfold expansion with µMagnify on a broad range of pathogen‐containing specimens, including bacterial and fungal biofilms, infected culture cells, fungus‐infected mouse tone, and formalin‐fixed paraffin‐embedded human cornea infected by various pathogens. Additionally, an associated virtual reality tool is developed to facilitate the visualization and navigation of complex 3D images generated by this method in an immersive environment allowing collaborative exploration among researchers worldwide. µMagnify is a valuable imaging platform for studying how microbes interact with their host systems and enables the development of new diagnosis strategies against infectious diseases.

Epithelial resident memory T (eTRM) cells serve as sentinels in barrier tissues to guard against previously encountered pathogens. How eTRM cells are generated has important implications for efforts to elicit their formation through vaccination or prevent it in autoimmune disease. Here, we show that during immune homeostasis, the cytokine transforming growth factor β (TGF-β) epigenetically conditions resting naïve CD8+ T cells and prepares them for the formation of eTRM cells in a mouse model of skin vaccination. Naïve T cell conditioning occurs in lymph nodes (LNs), but not in the spleen, through major histocompatibility complex class I-dependent interactions with peripheral tissue-derived migratory dendritic cells (DCs) and depends on DC expression of TGF-β-activating αV integrins. Thus, the preimmune T cell repertoire is actively conditioned for a specialized memory differentiation fate through signals restricted to LNs.

Traditionally the lactation cycle of a dairy cow is based around a 12-month calving interval, allowing for 10 months of lactation, followed by a 2-month dry period. This means that the cow has to conceive within 2-3 months after calving, when she is also at peak lactation and metabolically is in a negative energy balance. Such challenging physiological conditions make it challenging for the cow to conceive at this time and many modern high-producing cows fail to get pregnant within the constraints of a 12-month calving interval. In addition, many cows still produce at a high level at drying-off time, increasing the risk of intramammary infections. Therefore, delaying conception past peak production and, as a result, extending the lactation beyond 10 months may increasingly be necessary. Additionally, extended lactation (EL) may offer other advantages such as fewer calves being born and thus fewer 'surplus' calves needing to be culled at a young age, fewer health and welfare issues and improved environmental outcomes (i.e. less greenhouse-gas emission; less antibiotic usage) during the lifetime of the animal. Extending lactation is a straight forward management practice in high-input dairy systems where a consistent supply of feed supplements is readily available, but may be more challenging to implement in low(er)-input pasture-based systems. The latter are much more seasonal, with a 12-month calving interval allowing pasture growth and quality to match the cow's nutritional demands; cows calve in spring when high-quality pasture is abundant and are dried-off during winter when pasture growth is more limited. In this review, we explored the impact of EL in both high-input systems and pasture-based systems. It covers the effects of EL on milk production, composition and processing, as well as on reproductive performance, health and welfare, and environmental and economic outcomes. [ABSTRACT FROM AUTHOR]

Background Following endoscopic retrograde cholangiopancreatography (ERCP), post-ERCP pancreatitis (PEP) is the most common complication. The host's innate immune response to periprocedural pancreatic injury is the hallmark of its pathogenesis. Investigating cytokine signatures associated with PEP and its risk factors can guide understanding of PEP immunopathogenesis. Methods We conducted a single-center, prospective, observational pilot study in adults at high-risk for PEP. Seven serum cytokines relevant to early acute pancreatitis pathogenesis, angiopoietin-2, hepatocyte growth factor (HGF), interleukin-6 (IL-6), IL-8, monocyte chemotactic protein-1, resistin, and soluble tumor necrosis factor-a receptor 1, were measured in sera collected 2 h pre- and post-ERCP. Levels were compared among healthy controls and ERCP participants who either did or did not develop PEP. Heat maps were constructed to perform a multidimensional exploratory analysis that aimed to determine the cytokine signatures associated with PEP and its participant-related risk factors (female sex, young age, and obesity). Results A total of 65 participants were enrolled (36 undergoing ERCP and 29 healthy controls). Eight of the 36 (22.2%) ERCP participants developed PEP. Baseline IL-8 levels measured before ERCP were elevated in participants who developed PEP (7.5 vs. 14.8 pg/mL, P=0.02), and most strongly upregulated in women under 40 years of age. HGF levels post-ERCP were higher in participants with PEP (738.0 vs. 556.6 pg/mL, P=0.04), and most strongly upregulated in obese participants. Conclusions Pre-ERCP IL-8 and post-ERCP HGF are associated with the development of PEP. Findings from this pilot study can inform the design of translational work in the immunopathogenesis of PEP. [ABSTRACT FROM AUTHOR]

Myofibroblasts are the major source of extracellular matrix components that accumulate during tissue fibrosis, and hepatic stellate cells (HSCs) are believed to be the major source of myofibroblasts in the liver. To date, robust systems to genetically manipulate these cells have not been developed. We report that Cre under control of the promoter of Pdgfrb (Pdgfrb-Cre) inactivates loxP-flanked genes in mouse HSCs with high efficiency. We used this system to delete the gene encoding α(v) integrin subunit because various α(v)-containing integrins have been suggested as central mediators of fibrosis in multiple organs. Such depletion protected mice from carbon tetrachloride-induced hepatic fibrosis, whereas global loss of β₃, β₅ or β₆ integrins or conditional loss of β₈ integrins in HSCs did not. We also found that Pdgfrb-Cre effectively targeted myofibroblasts in multiple organs, and depletion of the α(v) integrin subunit using this system was protective in other models of organ fibrosis, including pulmonary and renal fibrosis. Pharmacological blockade of α(v)-containing integrins by a small molecule (CWHM 12) attenuated both liver and lung fibrosis, including in a therapeutic manner. These data identify a core pathway that regulates fibrosis and suggest that pharmacological targeting of all α(v) integrins may have clinical utility in the treatment of patients with a broad range of fibrotic diseases.

In the mammalian gut CD103+ve myeloid DCs are known to suppress inflammation threatened by luminal bacteria, but stimuli driving DC precursor maturation towards this beneficial phenotype are incompletely understood. We isolated CD11+ve DCs from mesenteric lymph nodes (MLNs) of healthy mice; CD103+ve DCs were 8-24 fold more likely than CD103-ve DCs to exhibit extensive of prior phagocytosis of apoptotic intestinal epithelial cells. However, CD103+ve and CD103-ve MLN DCs exhibited similar ex vivo capacity to ingest apoptotic cells, indicating that apoptotic cells might drive immature DC maturation towards the CD103+ve phenotype. When cultured with apoptotic cells, myeloid DC precursors isolated from murine bone marrow and characterised as lineage-ve CD103-ve, displayed enhanced expression of CD103 and β8 integrin and acquired increased capacity to induce T regulatory lymphocytes (Tregs) after 7d in vitro. However, DC precursors isolated from αv-tie2 mice lacking αv integrins in the myeloid line exhibited reduced binding of apoptotic cells and complete deficiency in the capacity of apoptotic cells and/or latent TGF-β1 to enhance CD103 expression in culture, whereas active TGF-β1 increased DC precursor CD103 expression irrespective of αv expression. Fluorescence microscopy revealed clustering of αv integrin chains and latent TGF-β1 at points of contact between DC precursors and apoptotic cells. We conclude that myeloid DC precursors can deploy αv integrin to orchestrate binding of apoptotic cells, activation of latent TGF-β1 and acquisition of the immunoregulatory CD103+ve β8+ve DC phenotype. This implies that a hitherto unrecognised consequence of apoptotic cell interaction with myeloid phagocytes is programming that prevents inflammation.

Pore-forming toxins (PFTs) are the largest class of bacterial toxins and contribute to virulence by triggering host cell death. Vertebrates also express endogenous pore-forming proteins that induce cell death as part of host defense. To mitigate damage and promote survival, cells mobilize membrane repair mechanisms to neutralize and counteract pores, but how these pathways are activated is poorly understood. Here, we use a transposon-based gene activation screen to discover pathways that counteract the cytotoxicity of the archetypal PFT Staphylococcus aureus α-toxin. We identify the endolysosomal protein LITAF as a mediator of cellular resistance to PFT-induced cell death that is active against both bacterial toxins and the endogenous pore, gasdermin D, a terminal effector of pyroptosis. Activation of the ubiquitin ligase NEDD4 by potassium efflux mobilizes LITAF to recruit the endosomal sorting complexes required for transport (ESCRT) machinery to repair damaged membrane. Cells lacking LITAF, or carrying naturally occurring disease-associated mutations of LITAF, are highly susceptible to pore-induced death. Notably, LITAF-mediated repair occurs at endosomal membranes, resulting in expulsion of damaged membranes as exosomes, rather than through direct excision of pores from the surface plasma membrane. These results identify LITAF as a key effector that links sensing of cellular damage to repair. Editor's summary: Membrane pores caused by bacterial pore-forming toxins (PFTs) or endogenous pore-forming proteins can trigger cell death. Membrane repair machinery can promote cell survival and resistance to PFTs, but the cellular mechanisms underlying defense against these toxins are not well defined. Stefani et al. performed a transposon mutagenesis screen to identify genes involved in resistance to Staphylococcus aureus α-toxin–induced cell death. They identified that LITAF, an endolysosomal protein, was required for cell survival after α-toxin– and gasdermin D–induced cell death. K+ efflux through membrane pores promoted LITAF localization to endosomes containing α-toxin and initiated assembly of ESCRT machinery, resulting in secretion of damaged membrane in exosomes. This work uncovers a key role for LITAF in sensing plasma membrane damage and activating membrane repair machinery. —Hannah Isles [ABSTRACT FROM AUTHOR]

Integrins regulate haematopoietic stem cell (HSC) homeostasis and engraftment into the bone marrow (BM) niche upon transplantation. Here, the authors show that HSC quiescence and function in the BM is regulated by the interaction of PERIOSTIN and INTEGRIN αv and subsequent increase in p27Kip1.

Integrins can regulate antigen-specific and innate immune receptor signalling, thereby affecting immune cell function. Here the authors show that avß3 integrin controls Toll-like receptor (TLR) signalling by regulating its trafficking to limit TLR-mediated B-cell proliferation and antibody production.