Induction Of Cytokines Research Articles

The GPR84 molecule is a mediator of a subpopulation of retinal microglia that promote TNF/IL-1α expression via the rho-ROCK pathway after optic nerve injury.

Resident microglia are important to maintain homeostasis in the central nervous system, which includes the retina. The retinal microglia become activated in numerous pathological conditions, but the molecular signatures of these changes are poorly understood. Here, using an approach based on FACS and RNA-seq, we show that microglial gene expression patterns gradually change during RGC degeneration induced by optic nerve injury. Most importantly, we found that the microglial cells strongly expressed Tnf and Il1α, both of which are known to induce neurotoxic reactive astrocytes, and were characterized by Gpr84high -expressing cells in a particular subpopulation. Moreover, ripasudil, a Rho kinase inhibitor, significantly blunted Gpr84 expression and cytokine induction in vitro and in vivo. Finally, GPR84-deficient mice prevented RGC loss in optic nerve-injured retina. These results reveal that Rho kinase-mediated GPR84 alteration strongly contribute to microglial activation and promote neurotoxicity, suggesting that Rho-ROCK and GPR84 signaling may be potential therapeutic targets to prevent the neurotoxic microglial phenotype induced by optic nerve damage, such as occurs in traumatic optic neuropathy and glaucoma.

Extended cleavage specificities of human granzymes A and K, two closely related enzymes with conserved but still poorly defined functions in T and NK cell-mediated immunity.

Granzymes A and K are two highly homologous serine proteases expressed by mammalian cytotoxic T cells (CTL) and natural killer cells (NK). Granzyme A is the most abundant of the different granzymes (gzms) expressed by these two cell types. Gzms A and K are found in all jawed vertebrates and are the most well conserved of all hematopoietic serine proteases. Their potential functions have been studied extensively for many years, however, without clear conclusions. Gzm A was for many years thought to serve as a key component in the defense against viral infection by the induction of apoptosis in virus-infected cells, similar to gzm B. However, later studies have questioned this role and instead indicated that gzm A may act as a potent inducer of inflammatory cytokines and chemokines. Gzms A and K form clearly separate branches in a phylogenetic tree indicating separate functions. Transcriptional analyses presented here demonstrate the presence of gzm A and K transcripts in both CD4+ and CD8+ T cells. To enable screening for their primary biological targets we have made a detailed analysis of their extended cleavage specificities. Phage display analysis of the cleavage specificity of the recombinant enzymes showed that both gzms A and K are strict tryptases with high selectivity for Arg over Lys in the P1 position. The major differences in the specificities of these two enzymes are located N-terminally of the cleavage site, where gzm A prefers small amino acids such as Gly in the P3 position and shows a relatively relaxed selectivity in the P2 position. In contrast, gzm K prefers large amino acids such as Phe, Tyr, and Trp in both the P2 and P3 positions and does not tolerate negatively charged residues in the P2 position. This major distinction in extended specificities is likely reflected also in preferred in vivo targets of these two enzymes. This information can now be utilized for high-precision screening of primary targets for gzms A and K in search of their highly conserved but still poorly defined functions in vertebrate immunity.

Ex vivo infection model for Francisella using human lung tissue.

Tularemia is mainly caused by Francisella tularensis (Ft) subsp. tularensis (Ftt) and Ft subsp. holarctica (Ftt) in humans and in more than 200 animal species including rabbits and hares. Human clinical manifestations depend on the route of infection and range from flu-like symptoms to severe pneumonia with a mortality rate up to 60% without treatment. So far, only 2D cell culture and animal models are used to study Francisella virulence, but the gained results are transferable to human infections only to a certain extent. In this study, we firstly established an ex vivo human lung tissue infection model using different Francisella strains: Ftt Life Vaccine Strain (LVS), Ftt LVS ΔiglC, Ftt human clinical isolate A-660 and a German environmental Francisella species strain W12-1067 (F-W12). Human lung tissue was used to determine the colony forming units and to detect infected cell types by using spectral immunofluorescence and electron microscopy. Chemokine and cytokine levels were measured in culture supernatants. Only LVS and A-660 were able to grow within the human lung explants, whereas LVS ΔiglC and F-W12 did not replicate. Using human lung tissue, we observed a greater increase of bacterial load per explant for patient isolate A-660 compared to LVS, whereas a similar replication of both strains was observed in cell culture models with human macrophages. Alveolar macrophages were mainly infected in human lung tissue, but Ftt was also sporadically detected within white blood cells. Although Ftt replicated within lung tissue, an overall low induction of pro-inflammatory cytokines and chemokines was observed. A-660-infected lung explants secreted slightly less of IL-1β, MCP-1, IP-10 and IL-6 compared to Ftt LVS-infected explants, suggesting a more repressed immune response for patient isolate A-660. When LVS and A-660 were used for simultaneous co-infections, only the ex vivo model reflected the less virulent phenotype of LVS, as it was outcompeted by A-660. We successfully implemented an ex vivo infection model using human lung tissue for Francisella. The model delivers considerable advantages and is able to discriminate virulent Francisella from less- or non-virulent strains and can be used to investigate the role of specific virulence factors.

Identification and elucidation of cross talk between SLAM Family Member 7 (SLAMF7) and Toll-like receptor (TLR) pathways in monocytes and macrophages

To further elucidate the expression, regulation and function of Signaling Lymphocytic Activation Molecule Family (SLAMF) protein members in human monocytes and macrophages. Un-differentiated monocytic THP-1 cell (u-THP-1) and differentiated THP-1 macrophage (d-THP-1) were used as culture models in the study. Responses of cells to the differentiation agents phorbol ester (25 ng/ml) and TLR (Toll-like receptor) ligands were assessed. RT-PCR and Western blot analysis were used to determine mRNA and protein level. Pro-inflammatory cytokine mRNA expression levels and phagocytosis were used as functional markers. Data analyzed using t-test, one-way or two-way ANOVA followed by post hoc test. SLAMFs were differentially expressed in THP-1 cells. Differentiation of u-THP-1 to d-THP-1 led to significantly higher SLAMF7 mRNA and protein levels than other SLAMF. In addition, TLR stimuli increased SLAMF7 mRNA expression but not protein expression. Importantly, SLAMF7 agonist antibody and TLR ligands synergistically increased the mRNA expression levels of IL-1β, IL-6 and TNF-α, but had no effect on phagocytosis. SLAMF7 knocked-down in d-THP-1 significantly lowered TLR-induced mRNA expressions of pro-inflammatory markers. SLAM family proteins are differentially regulated by differentiation and TLRs. SLAMF7 enhanced TLR-mediated induction of pro-inflammatory cytokines in monocytes and macrophages but not phagocytosis.

Aging exaggerates pulpal pain sensation by increasing the expression levels of nociceptive neuropeptides and inflammatory cytokines

BackgroundDental pain is a main clinical problem in the elderly population and its assessment and treatment make special challenges for health care services. However, the age-induced alteration in dental pain perception and the underlying molecular mechanism(s) has not yet been fully clarified. MethodsHere, the effect of aging on nociceptive behaviors following inflammatory dental pulp pain was evaluated. Since prostaglandins, nociceptive neuropeptides, and inflammatory cytokines have critical roles in the development of aging as well as pain signaling, the expression levels of COX-2, CGRP, IL-1β, IL-6, TNF-α and its converting enzyme TACE were assessed in the trigeminal ganglion of young and aged rats with dental pain. Dental pulp pain was induced by intradental application of capsaicin (100 μg). The immunofluorescence (COX-2 and CGRP) and western blot techniques were used. ResultsThe data showed that aged animals have different pattern of pain. So that, the mean of nociceptive scores was significantly greater in aged rats at 10 and 15 min after capsaicin injection. In aged rats, dental pain was persisting over 7 h, while it was disappeared at 300 min in young rats. Molecular data showed that dental pain significantly increased the expression of COX-2, CGRP, IL-1β, IL-6, TNF-α and TACE in the trigeminal ganglion of the young and aged rats. In addition, the amount of those parameters, except TACE, in capsaicin-treated aged animals were significantly (p < 0.05) greater than those in capsaicin-treated young rats. ConclusionIt seems that the induction of pro-inflammatory cytokines in an acute inflammatory pulpal pain model may contribute, at least in part to the increased nociceptive behaviors and pain perception in aged rats.

TWEAK Progress in Dermatology: A Review.

Tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a member of the TNF superfamily (TNFSF). It acts through its receptor fibroblast growth factor-inducible 14 (Fn14). Studies have indicated that TWEAK/Fn14 pathway activation controls multiple cellular responses, including proliferation, angiogenesis and induction of inflammatory cytokines. TWEAK/Fn14 is manifested in many tissues of our body and most importantly in the skin causing inflammation and many autoimmune and neoplastic cutaneous disorders. Evidence suggests that the TWEAK/Fn14 axis, the downstream signalling pathway and its inflammatory molecular expressions are involved in the pathogenesis of many cutaneous disorders such as psoriasis, atopic dermatitis (AD) vitiligo and melanoma. So, this literature review describes a brief introduction of TWEAK and TWEAK/Fn14 pathway and summarises the case-series and open-label studies performed in the field of dermatology and its potential therapeutic benefit.

Coordinated Transcriptional Waves Define the Inflammatory Response of Primary Microglial Culture.

The primary role of microglia is to maintain homeostasis by effectively responding to various disturbances. Activation of transcriptional programs determines the microglia's response to external stimuli. In this study, we stimulated murine neonatal microglial cells with benzoyl ATP (bzATP) and lipopolysaccharide (LPS), and monitored their ability to release pro-inflammatory cytokines. When cells are exposed to bzATP, a purinergic receptor agonist, a short-lived wave of transcriptional changes, occurs. However, only combining bzATP and LPS led to a sustainable and robust response. The transcriptional profile is dominated by induced cytokines (e.g., IL-1α and IL-1β), chemokines, and their membrane receptors. Several abundant long noncoding RNAs (lncRNAs) are induced by bzATP/LPS, including Ptgs2os2, Bc1, and Morrbid, that function in inflammation and cytokine production. Analyzing the observed changes through TNF (Tumor necrosis factor) and NF-κB (nuclear factor kappa light chain enhancer of activated B cells) pathways confirmed that neonatal glial cells exhibit a distinctive expression program in which inflammatory-related genes are upregulated by orders of magnitude. The observed capacity of the microglial culture to activate a robust inflammatory response is useful for studying neurons under stress, brain injury, and aging. We propose the use of a primary neonatal microglia culture as a responsive in vitro model for testing drugs that may interact with inflammatory signaling and the lncRNA regulatory network.

Exosome-like nanoparticles derived from Allium tuberosum prevent neuroinflammation in microglia-like cells.

Exosome-like nanoparticles (ELNs), which are plant-derived extracellular membrane vesicles, can regulate mammalian gene expression. ELNs can cross the blood-brain barrier, making them potential therapeutic agents or drug-delivery carriers for neuroinflammation-related diseases. Here, we investigated the anti-neuroinflammatory potential of ELNs extracted from Allium tuberosum (A-ELNs). A-ELNs were extracted, and their miRNA profile was characterized. A-ELNs were also applied to BV-2 microglial and MG-6 cells derived from C57/BL6 mice stimulated with lipopolysaccharide (LPS), followed by an examination of levels of inflammatory-related factors. To test their drug-carrying potential, A-ELNs were mixed with dexamethasone, an anti-inflammatory drug, to prepare dexamethasone-incorporated A-ELNs (Dex-A-ELNs). A-ELNs showed a particle size of 145 ± 2 nm and characteristic miRNAs. A-ELNs significantly decreased the LPS-induced nitric oxide (NO) and inflammatory cytokines levels in BV-2 and MG-6 cells. The mRNA expression of heme oxygenase-1 was significantly increased, and that of inducible NO synthase and inflammatory cytokines was significantly decreased by A-ELNs in BV-2 cells. Dex-A-ELNs inhibited NO production in BV-2 cells more potently than either A-ELNs or dexamethasone alone. A-ELNs can alleviate microglial inflammation. Their effects can be potentiated by incorporating anti-inflammatory drugs, such as dexamethasone, making them potential therapeutic agents or drug-delivery carriers for neuroinflammation.

The homodimer interfaces of costimulatory receptors B7 and CD28 control their engagement and pro-inflammatory signaling

BackgroundThe inflammatory response is indispensable for protective immunity, yet microbial pathogens often trigger an excessive response, ‘cytokine storm’, harmful to the host. Full T-cell activation requires interaction of costimulatory receptors B7-1(CD80) and B7-2(CD86) expressed on antigen-presenting cells with CD28 expressed on the T cells. We created short peptide mimetics of the homodimer interfaces of the B7 and CD28 receptors and examined their ability to attenuate B7/CD28 coligand engagement and signaling through CD28 for inflammatory cytokine induction in human immune cells, and to protect from lethal toxic shock in vivo.MethodsShort B7 and CD28 receptor dimer interface mimetic peptides were synthesized and tested for their ability to attenuate the inflammatory cytokine response of human peripheral blood mononuclear cells, as well as for their ability to attenuate B7/CD28 intercellular receptor engagement. Mice were used to test the ability of such peptides to protect from lethal superantigen toxin challenge when administered in molar doses far below the toxin dose.ResultsB7 and CD28 homodimer interfaces are remote from the coligand binding sites, yet our finding is that by binding back into the receptor dimer interfaces, short dimer interface mimetic peptides inhibit intercellular B7-2/CD28 as well as the tighter B7-1/CD28 engagement, attenuating thereby pro-inflammatory signaling. B7 mimetic peptides exhibit tight selectivity for the cognate receptor in inhibiting intercellular receptor engagement with CD28, yet each diminishes signaling through CD28. In a prominent example of inflammatory cytokine storm, by attenuating formation of the B7/CD28 costimulatory axis, B7-1 and CD28 dimer interface mimetic peptides protect mice from lethal toxic shock induced by a bacterial superantigen even when administered in doses far submolar to the superantigen.ConclusionsOur results reveal that the B7 and CD28 homodimer interfaces each control B7/CD28 costimulatory receptor engagement and highlight the protective potential against cytokine storm of attenuating, yet not ablating, pro-inflammatory signaling via these receptor domains.

Remodeled eX vivo muscle engineered tissue improves heart function after chronic myocardial ischemia

The adult heart displays poor reparative capacities after injury. Cell transplantation and tissue engineering approaches have emerged as possible therapeutic options. Several stem cell populations have been largely used to treat the infarcted myocardium. Nevertheless, transplanted cells displayed limited ability to establish functional connections with the host cardiomyocytes. In this study, we provide a new experimental tool, named 3D eX vivo muscle engineered tissue (X-MET), to define the contribution of mechanical stimuli in triggering functional remodeling and to rescue cardiac ischemia. We revealed that mechanical stimuli trigger a functional remodeling of the 3D skeletal muscle system toward a cardiac muscle-like structure. This was supported by molecular and functional analyses, demonstrating that remodeled X-MET expresses relevant markers of functional cardiomyocytes, compared to unstimulated and to 2D- skeletal muscle culture system. Interestingly, transplanted remodeled X-MET preserved heart function in a murine model of chronic myocardial ischemia and increased survival of transplanted injured mice. X-MET implantation resulted in repression of pro-inflammatory cytokines, induction of anti-inflammatory cytokines, and reduction in collagen deposition. Altogether, our findings indicate that biomechanical stimulation induced a cardiac functional remodeling of X-MET, which showed promising seminal results as a therapeutic product for the development of novel strategies for regenerative medicine.

In-Silico CLEC5A mRNA expression analysis to predict Dengue susceptibility in cancer patients

Dengue fever is the fastest-growing infectious disease in the world. It is the leading vector-borne viral neglected tropical disease. The most acute immune response to dengue virus infection is dengue shock syndrome and hemorrhagic fever, which is due to the activation of CLEC5A C-type lectin domain family 5, member A (CLEC5A). It is a cell surface receptor, and its well-known ligand is the dengue virus. It gets activated by the attachment of dengue virion, which, as a result, phosphorylates its adaptor protein DAP12 leading to the induction of various pro-inflammatory cytokines. Clinical data suggested that the kidneys and lungs are among the major hit organs in the case of severe dengue infection. Here we predict kidney and lung cancer patients are vulnerable to dengue virus infection as CLEC5A mRNA expression in tumor samples using publicly available software such as TIMER and GEPIA database. We also identified the immunomodulatory role CLEC5A gene therefore targeting it could be a vital tool to cure dengue.

Proinflammatory cytokine profiles in prediabetic Saudi patients

Prediabetes is an increase-risk state for diabetes that is associated with an increase in blood glucose levels to more than normal, but not increased enough to be termed as type 2 diabetes mellitus (T2DM). A timely intervention and management of prediabetes can stop its further progression to the diabetic state. Many cytokines are involved in diseases including diabetes, however, their role in prediabetes is unknown. In this study, we attempted to analyze numerous proinflammatory cytokines in prediabetic patients. A total of 60 adult Saudi prediabetes patients and healthy control individuals were included in this study. To better understand the role of the proinflammatory cytokines in prediabetes patients and its potential link to the disease outcome, the variations in the levels of these cytokines were investigated using Multi-Analyte ELISA technique. The T helper cells (Th1 and Th2) immune response expression profiling of 84 genes was done using Real Time-quantitative PCR (RT-qPCR) technique. The present finding showed that serum Interleukin IL-2, IL-1β, and IL-1α levels of all prediabetes patients were increased when compared with healthy control cases (P < 0.05). Inductions of proinflammatory cytokines and upregulation of Th1 and Th2 immune genes might play a potential role during prediabetes status and may be linked to the disease outcome. Further studies are needed to investigate the underlying mechanism of these proinflammatory cytokines in diabetes development. A strong positive correlation was found between IL and 1α with glucose levels than with IL-1β and IL-2. In conclusion, cytokines, especially IL-1, may play a critical role in the development of diabetes.

The Anti-Inflammatory Effects of Cannabis sativa Extracts on LPS-Induced Cytokines Release in Human Macrophages.

Inflammation is the response of the innate immune system to any type of injury. Although acute inflammation is critical for survival, dysregulation of the innate immune response leads to chronic inflammation. Many synthetic anti-inflammatory drugs have side effects, and thus, natural anti-inflammatory compounds are still needed. Cannabis sativa L. may provide a good source of anti-inflammatory molecules. Here, we tested the anti-inflammatory properties of cannabis extracts and pure cannabinoids in lipopolysaccharide (LPS)-induced inflammation in human THP-1 macrophages. We found that pre-treatment with cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC), or extracts containing high levels of CBD or THC reduced the level of induction of various cytokines. The CBD was more efficient than THC, and the extracts were more efficient than pure cannabinoids. Finally, IL-6, IL-10, and MCP-1 cytokines were most sensitive to pre-treatments with CBD and THC, while IL-1β, IL-8, and TNF-α were less responsive. Thus, our work demonstrates the potential of the use of cannabinoids or/and cannabis extracts for the reduction of inflammation and establishes IL-6 and MCP-1 as the sensitive markers for the analysis of the effect of cannabinoids on inflammation in macrophages.

Yuja Juice and Concentrate Enhance Immunomodulating Effects via Increasing Immune-Related Cytokines in RAW264.7 Cells and Mouse Splenocytes.

Good immunity is highly valued in modern society. Although yuja's efficacy in immunity enhancement has been elucidated, there have been few studies on its role. In this study, we investigate the immune enhancement activity of yuja juice extracts (YJEs) and yuja concentrate extracts (YCEs). The immunoregulatory potencies of YJE and YCE were examined by determining cell viability and the expression of cytokines and immune-related molecules in RAW264.7 cells and mouse primary splenocytes. YJE and YCE induced the production of inducible nitric oxide synthase and cytokines (IL-10, IL-4, IL-6, and IFN-γ) at 1000 μg/mL concentration in RAW 264.7 cells. In addition, in mice that were orally administered 3000 or 2000 mg/kg concentrations of YJE or YCE, immune-related cytokines in splenocytes were boosted to levels higher than those in control mice. Importantly, no liver toxicity was observed at all doses. Thus, our results suggest that compounds present in YJEs and YCEs represent novel natural immune-modulatory substances.

Novel nanoadjuvants balance immune activation with modest inflammation: implications for older adult vaccines

BackgroundAge-associated impairments of immune response and inflammaging likely contribute to poor vaccine efficacy. An appropriate balance between activation of immune memory and inflammatory response may be more effective in vaccines for older adults; attempts to overcome reduced efficacy have included the addition of adjuvants or increased antigenic dose. Next generation vaccine formulations may also use biomaterials to both deliver and adjuvant vaccine antigens. In the context of aging, it is important to determine the degree to which new biomaterials may enhance antigen-presenting cell (APC) functions without inducing potent inflammatory responses of APCs or other immune cell types (e.g., T cells). However, the effect of newer biomaterials on these cell types from young and older adults remains unknown.ResultsIn this pilot study, cells from young and older adults were used to evaluate the effect of novel biomaterials such as polyanhydride nanoparticles (NP) and pentablock copolymer micelles (Mi) and cyclic dinucleotides (CDN; a STING agonist) on cytokine and chemokine secretion in comparison to standard immune activators such as lipopolysaccharide (LPS) and PMA/ionomycin. The NP treatment showed adjuvant-like activity with induction of inflammatory cytokines, growth factors, and select chemokines in peripheral blood mononuclear cells (PBMCs) of both young (n = 6) and older adults (n = 4), yet the degree of activation was generally less than LPS. Treatment with Mi or CDN resulted in minimal induction of cytokines and chemokine secretion with the exception of increased IFN-α and IL-12p70 by CDN. Age-related decreases were observed across multiple cytokines and chemokines, yet IFN-α, IL-12, and IL-7 production by NP or CDN stimulation was equal to or greater than in cells from younger adults. Consistent with these results in aged humans, a combination nanovaccine composed of NP, Mi, and CDN administered to aged mice resulted in a greater percentage of antigen-specific CD4+ T cells and greater effector memory cells in draining lymph nodes compared to an imiquimod-adjuvanted vaccine.ConclusionsOverall, our novel biomaterials demonstrated a modest induction of cytokine secretion with a minimal inflammatory profile. These findings suggest a unique role for biomaterial nanoadjuvants in the development of next generation vaccines for older adults.

Effects of Moringa oleifera Seed Oil on Cultured Human Sebocytes In Vitro and Comparison with Other Oil Types.

The seeds of Moringa oleifera (horseradish tree) contain about 40% of one of the most stable vegetable oils (Moringa seed oil). Therefore, the effects of Moringa seed oil on human SZ95 sebocytes were investigated and were compared with other vegetable oils. Immortalized human SZ95 sebocytes were treated with Moringa seed oil, olive oil, sunflower oil, linoleic acid and oleic acid. Lipid droplets were visualized by Nile Red fluorescence, cytokine secretion via cytokine antibody array, cell viability with calcein-AM fluorescence, cell proliferation by real-time cell analysis, and fatty acids were determined by gas chromatography. Statistical analysis was performed by the Wilcoxon matched-pairs signed-rank test, the Kruskal-Wallis test and Dunn's multiple comparison test. The vegetable oils tested stimulated sebaceous lipogenesis in a concentration-dependent manner. The pattern of lipogenesis induced by Moringa seed oil and olive oil was comparable to lipogenesis stimulated by oleic acid with also similar fatty acid secretion and cell proliferation patterns. Sunflower oil induced the strongest lipogenesis among the tested oils and fatty acids. There were also differences in cytokine secretion, induced by treatment with different oils. Moringa seed oil and olive oil, but not sunflower oil, reduced the secretion of pro-inflammatory cytokines, in comparison to untreated cells, and exhibited a low n-6/n-3 index. The anti-inflammatory oleic acid detected in Moringa seed oil probably contributed to its low levels of pro-inflammatory cytokine secretion and induction of cell death. In conclusion, Moringa seed oil seems to concentrate several desired oil properties on sebocytes, such as high content level of the anti-inflammatory fatty acid oleic acid, induction of similar cell proliferation and lipogenesis patterns compared with oleic acid, lipogenesis with a low n-6/n-3 index and inhibition of secretion of pro-inflammatory cytokines. These properties characterize Moringa seed oil as an interesting nutrient and a promising ingredient in skin care products.

#5811 URINARY CXCL9 AND CXCL10 CONCENTRATIONS AND KIDNEY TRANSPLANT INJURY

Abstract Background and Aims Kidney transplant rejection is diagnosed by the kidney biopsy which is an invasive diagnostic method, however, non-invasive biomarkers, distinguishing normal kidney transplant from transplant rejection would be prefered but are lacking. CXC chemokine ligand 9 (CXCL9) and CXC chemokine ligand 10 (CXCL10) are gamma interferon inducible small cytokines. The aim of this study was to evaluate urinary CXCL9 and CXCL10 as potential biomarkers of allograft rejection. Method 117 kidney transplant recipients undergoing kidney transplant biopsy (surveillance or indication) were included into this study. Spot urine samples were collected before kidney biopsy for urinary creatinine, CXCL9 and CXCL10 measurement. The ratios of CXCL9 over urinary creatinine and CXCL10 over urinary creatinine were calculated. Kidney biopsies were analyzed according to Banff criteria by an experienced pathologist. Results 26 (22.2%) of kidney biopsies were defined as normal histology, 24 (20.5%) – antibody mediated rejection, 9 (7.7%) – T cell mediated rejection, 10 (8.6%) mixed rejection, 5 (4.3%) BK virus nephopathy and 43 (36.8%) were defined as other histological lesions. Average CXCL9/creatinine was 0.39 ng/mmol in normal histology group and 12.1 ng/mmol in allograft rejection groups (p&amp;lt;0.01). Average CXCL10/creatinine was 0.26 ng/mmol in normal histology and 4.55 ng/mmol in allograft rejection group (p&amp;lt;0.01). CXCL9/creatinine and CXCL10 moderately correlated to proteinuria at the time of kidney biopsy (accordingly r = 0.595, p&amp;lt;0.01 and r = 0.408, p&amp;lt;0.01). ROC curve for CXCL9/creatinine detecting antibody mediated rejection was 0.79, CI 0.67 to 0.90, p&amp;lt;0.01. ROC curve for CXCL10/creatinine detecting antibody mediated rejection was 0.79, CI 0.64 to 0.94, p&amp;lt;0.01. Conclusion Urinary biomarkers CXCL9/creatinine and CXCL10/creatinine has a potential to distinguish normal renal histology from allograft rejection and correlates to proteinuria at the time of the biopsy.

Characterization of the Inflammatory Response Evoked by Bacterial Membrane Vesicles in Intestinal Cells Reveals an RIPK2-Dependent Activation by Enterotoxigenic Escherichia coli Vesicles.

Although the immunomodulatory potency of bacterial membrane vesicles (MVs) is widely acknowledged, their interactions with host cells and the underlying signaling pathways have not been well studied. Herein, we provide a comparative analysis of the proinflammatory cytokine profile secreted by human intestinal epithelial cells exposed to MVs derived from 32 gut bacteria. In general, outer membrane vesicles (OMVs) from Gram-negative bacteria induced a stronger proinflammatory response than MVs from Gram-positive bacteria. However, the quality and quantity of cytokine induction varied between MVs from different species, highlighting their unique immunomodulatory properties. OMVs from enterotoxigenic Escherichia coli (ETEC) were among those showing the strongest proinflammatory potency. In depth analyses revealed that the immunomodulatory activity of ETEC OMVs relies on a so far unprecedented two-step mechanism, including their internalization into host cells followed by intracellular recognition. First, OMVs are efficiently taken up by intestinal epithelial cells, which mainly depends on caveolin-mediated endocytosis as well as the presence of the outer membrane porins OmpA and OmpF on the MVs. Second, lipopolysaccharide (LPS) delivered by OMVs is intracellularly recognized by novel caspase- and RIPK2-dependent pathways. This recognition likely occurs via detection of the lipid A moiety as ETEC OMVs with underacylated LPS exhibited reduced proinflammatory potency but similar uptake dynamics compared to OMVs derived from wild-type (WT) ETEC. Intracellular recognition of ETEC OMVs in intestinal epithelial cells is pivotal for the proinflammatory response as inhibition of OMV uptake also abolished cytokine induction. The study signifies the importance of OMV internalization by host cells to exercise their immunomodulatory activities. IMPORTANCE The release of membrane vesicles from the bacterial cell surface is highly conserved among most bacterial species, including outer membrane vesicles (OMVs) from Gram-negative bacteria as well as vesicles liberated from the cytoplasmic membrane of Gram-positive bacteria. It is becoming increasingly evident that these multifactorial spheres, carrying membranous, periplasmic, and even cytosolic content, contribute to intra- and interspecies communication. In particular, gut microbiota and the host engage in a myriad of immunogenic and metabolic interactions. This study highlights the individual immunomodulatory activities of bacterial membrane vesicles from different enteric species and provides new mechanistic insights into the recognition of ETEC OMVs by human intestinal epithelial cells.

IFI16 phase separation via multi-phosphorylation drives innate immune signaling.

The interferon inducible protein 16 (IFI16) is a prominent sensor of nuclear pathogenic DNA, initiating innate immune signaling and suppressing viral transcription. However, little is known about mechanisms that initiate IFI16 antiviral functions or its regulation within the host DNA-filled nucleus. Here, we provide in vitroand in vivo evidence to establish that IFI16 undergoes liquid-liquid phase separation (LLPS) nucleated by DNA. IFI16 binding to viral DNA initiates LLPS and induction of cytokines during herpes simplex virus type 1 (HSV-1) infection. Multiple phosphorylation sites within an intrinsically disordered region (IDR) function combinatorially to activate IFI16 LLPS, facilitating filamentation. Regulated by CDK2 and GSK3β, IDR phosphorylation provides a toggle between active and inactive IFI16 and the decoupling of IFI16-mediated cytokine expression from repression of viral transcription. These findings show how IFI16 switch-like phase transitions are achieved with temporal resolution for immune signaling and, more broadly, the multi-layered regulation of nuclear DNA sensors.

Indoleamine 2,3-dioxygenase 1 regulates cell permissivity to astrovirus infection

Astroviruses cause a spectrum of diseases spanning asymptomatic infections to severe diarrhea, but little is understood about their pathogenesis. We previously determined that small intestinal goblet cells were the main cell type infected by murine astrovirus-1. Here, we focused on the host immune response to infection and inadvertently discovered a role for indoleamine 2,3-dioxygenase 1 (Ido1), a host tryptophan catabolizing enzyme, in the cellular tropism of murine and human astroviruses. We identified that Ido1 expression was highly enriched among infected goblet cells, and spatially corresponded to the zonation of infection. Because Ido1 can act as a negative regulator of inflammation, we hypothesized it could dampen host antiviral responses. Despite robust interferon signaling in goblet cells, as well as tuft cell and enterocyte bystanders, we observed delayed cytokine induction and suppressed levels of fecal lipocalin-2. Although we found Ido-/- animals were more resistant to infection, this was not associated with fewer goblet cells nor could it be rescued by knocking out interferon responses, suggesting that IDO1 instead regulates cell permissivity. We characterized IDO1-/- Caco-2 cells and observed significantly reduced human astrovirus-1 infection. Together this study highlights a role for Ido1 in astrovirus infection and epithelial cell maturation.