Revealing the oncogenic role of elevated GNL3L expression in esophageal squamous cell carcinoma: insights into the STAT3 pathway.

Background: Esophageal squamous cell carcinoma (ESCC) patients carries a poor prognosis, with limited effective therapeutic targets. This study aimed to clarify the clinical significance of guanine nucleotide-binding protein like 3-like (GNL3L) protein expression in ESCC and its role in malignant progression. Methods: GNL3L expression and associated cancer-promoting pathways in ESCC were interrogated via bioinformatics analysis through use of The Cancer Genome Atlas (TCGA) database. Subsequent verification of GNL3L protein expression in ESCC, coupled with clinical data, was conducted through immunohistochemistry and followed by a comprehensive prognostic analysis. We further investigated potential signaling pathways facilitating ESCC progression, employing a combination of bioinformatics analysis and immunohistochemical (IHC) experiments. Results: Bioinformatics analysis unveiled a significant elevation in GNL3L expression, particularly in gastrointestinal tumors and ESCC. Immunohistochemistry confirmed elevated GNL3L expression in ESCC tissues. Regression analysis established a correlation between elevated GNL3L expression and advanced tumor node metastasis (TNM) stage, with high expression associated with poor prognosis in patients with ESCC. Our integrated approach of bioinformatics and IHC analysis indicated a potential role of the signal transducers and activators of transcription 3 (STAT3) signaling pathway in ESCC progression. Conclusions: High GNL3L expression significantly contributes to the malignant progression of ESCC. This study further elucidates the mechanisms driving ESCC progression and offers possible insights for more effective diagnosis and treatment strategies.

Comparison of a selective STAT3 inhibitor with a dual STAT3/STAT1 inhibitor using a dextran sulfate sodium murine colitis model: new insight into the debate on selectivity.

Background: Recent advances in the treatment of inflammatory bowel disease include antitumor necrosis factor antibodies and the Janus kinase inhibitor tofacitinib, approved for ulcerative colitis. Janus kinase recruits signal transducers and activators of transcriptions (STAT), which are promising targets in inflammatory bowel diseases. However few inhibitors have been evaluated, and their selectivity with respect to STAT1 and STAT3 remains controversial. Here, we investigated the therapeutic potential of a selective inhibitor vs. a non-selective, closely related compound, in a dextran sulfate sodium (DSS) murine colitis model. Methods: Thirty Swiss/CD-1 male mice were used in this study. They were divided into a healthy control group, a colitis-DSS control group, a compound (cpd) 23-treated group, a cpd 46-treated group and an icariin-treated group. For the coadministration experiment with rutin, the cpd 46-treated group and the icariin-treated group were replaced by the oral rutin-treated group and the coadministration rutin/cpd 23-treated group. The effect of the tested inhibitors was also assessed by quantification of proinflammatory markers. Results: The selective inhibitor had a significantly greater effect than the dual inhibitor on the disease activity index. We also noticed in curative treatment a significant decrease in the most abundant proinflammatory biomarker present in neutrophilic granulocytes, myeloperoxidase and on proinflammatory cytokines, including tumor necrosis factor-α, interferon-γ, interleukins -6 and -23, with a mild synergy with rutin, the glycoside of quercetin. Conclusion: The current study shows how STAT3 selective inhibitors can exert a significant therapeutic effect in the treatment of experimental DSS-colitis.

The USP7-STAT3-granzyme-Par-1 axis regulates allergic inflammation by promoting differentiation of IL-5-producing Th2 cells.

Uncontrolled type 2 immunity by type 2 helper T (Th2) cells causes intractable allergic diseases; however, whether the interaction of CD4+ T cells shapes the pathophysiology of allergic diseases remains unclear. We identified a subset of Th2 cells that produced the serine proteases granzyme A and B early in differentiation. Granzymes cleave protease-activated receptor (Par)-1 and induce phosphorylation of p38 mitogen-activated protein kinase (MAPK), resulting in the enhanced production of IL-5 and IL-13 in both mouse and human Th2 cells. Ubiquitin-specific protease 7 (USP7) regulates IL-4-induced phosphorylation of STAT3, resulting in granzyme production during Th2 cell differentiation. Genetic deletion of Usp7 or Gzma and pharmacological blockade of granzyme B ameliorated allergic airway inflammation. Furthermore, PAR-1+ and granzyme+ Th2 cells were colocalized in nasal polyps from patients with eosinophilic chronic rhinosinusitis. Thus, the USP7-STAT3-granzymes-Par-1 pathway is a potential therapeutic target for intractable allergic diseases.

Ruxolitinib altered IFN-ß induced necroptosis of human dental pulp stem cells during osteoblast differentiation.

OBJECTIVE: This study aimed to evaluate the role of ruxolitinib in the interferon beta (IFN-ß) mediated osteoblast differentiation using human dental pulp stem cells (hDPSCs). DESIGN: hDPSCs from five deciduous teeth of healthy patients were stimulated by adding human recombinant IFN-ß protein (1 or 2 ng/ml) to the osteogenic differentiation induction medium. Substrate formation was determined using Alizarin Red staining, calcium concentration, and osteoblast marker expression levels. Ruxolitinib was used to inhibit the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathway. Apoptosis was detected using terminal deoxynucleotidyl nick-end labeling (TUNEL) staining, and necroptosis was detected using propidium iodide staining and phosphorylated mixed lineage kinase domain-like protein (pMLKL) expression. RESULTS: In the IFN-ß-treated group, substrate formation was inhibited by a reduction in alkaline phosphatase (ALP) expression in a concentration-dependent manner. Although the proliferation potency was unchanged between the IFN-ß-treated and control groups, the cell number was significantly reduced in the experimental group. TUNEL-positive cell number was not significantly different; however, the protein level of necroptosis markers, interleukin-6 (IL-6) and pMLKL were significantly increased in the substrate formation. Cell number and ALP expression level were improved in the group administered ruxolitinib, a JAK-STAT inhibitor. Additionally, ruxolitinib significantly suppressed IL-6 and pMLKL levels. CONCLUSION: Ruxolitinib interfered with the IFN-ß-mediated necroptosis and osteogenic differentiation via the JAK-STAT pathway.

The NSs protein of severe fever with thrombocytopenia syndrome virus differentially inhibits the type 1 interferon response among animal species.

Severe fever with thrombocytopenia syndrome virus (SFTSV), which has been reported in China, Korea, Japan, Vietnam, and Taiwan, is a causative agent of severe fever thrombocytopenia syndrome. This virus has a high mortality and induces thrombocytopenia and leukocytopenia in humans, cats, and aged ferrets, whereas immunocompetent adult mice infected with SFTSV never show symptoms. Anti-SFTSV antibodies have been detected in several animals-including goats, sheep, cattle, and pigs. However, there are no reports of severe fever thrombocytopenia syndrome in these animals. Previous studies have reported that the nonstructural protein NSs of SFTSV inhibits the type I interferon (IFN-I) response through the sequestration of human signal transducer and activator of transcription (STAT) proteins. In this study, comparative analysis of the function of NSs as IFN antagonists in human, cat, dog, ferret, mouse, and pig cells revealed a correlation between pathogenicity of SFTSV and the function of NSs in each animal. Furthermore, we found that the inhibition of IFN-I signaling and phosphorylation of STAT1 and STAT2 by NSs depended on the binding ability of NSs to STAT1 and STAT2. Our results imply that the function of NSs in antagonizing STAT2 determines the species-specific pathogenicity of SFTSV.

Selective JAK1 inhibitors for the treatment of inflammatory bowel disease.

Janus kinase (JAK) inhibitors, also known as jakinibs, are third-generation oral small molecules that have expanded the therapeutic options for the management of chronic inflammatory diseases, including inflammatory bowel disease (IBD). Tofacitinib, a pan-JAK inhibitor, has spearheaded the new JAK class for IBD treatment. Unfortunately, serious adverse effects, including cardiovascular complications such as pulmonary embolism and venous thromboembolism or even death from any cause, have been reported for tofacitinib. However, it is anticipated that next-generation selective JAK inhibitors may limit the development of serious adverse events, leading to a safer treatment course with these novel targeted therapies. Nevertheless, although this drug class was recently introduced, following the launch of second-generation biologics in the late 1990s, it is breaking new ground and has been shown to efficiently modulate complex cytokine-driven inflammation in both preclinical models and human studies. Herein, we review the clinical opportunities for targeting JAK1 signaling in the pathophysiology of IBD, the biology and chemistry underpinning these target-selective compounds, and their mechanisms of actions. We also discuss the potential for these inhibitors in efforts to balance their benefits and harms.

Strain-specific responsiveness of hepatitis D virus to interferon-alpha treatment.

Background & Aims: Pegylated interferon alpha (pegIFNα) is commonly used for the treatment of people infected with HDV. However, its mode of action in HDV-infected cells remains elusive and only a minority of people respond to pegIFNα therapy. Herein, we aimed to assess the responsiveness of three different cloned HDV strains to pegIFNα. We used a previously cloned HDV genotype 1 strain (dubbed HDV-1a) that appeared insensitive to interferon-α in vitro, a new HDV strain (HDV-1p) we isolated from an individual achieving later sustained response to IFNα therapy, and one phylogenetically distant genotype 3 strain (HDV-3). Methods: PegIFNα was administered to human liver chimeric mice infected with HBV and the different HDV strains or to HBV/HDV infected human hepatocytes isolated from chimeric mice. Virological parameters and host responses were analysed by qPCR, sequencing, immunoblotting, RNA in situ hybridisation and immunofluorescence staining. Results: PegIFNα treatment efficiently reduced HDV RNA viraemia (∼2-log) and intrahepatic HDV markers both in mice infected with HBV/HDV-1p and HBV/HDV-3. In contrast, HDV parameters remained unaffected by pegIFNα treatment both in mice (up to 9 weeks) and in isolated cells infected with HBV/HDV-1a. Notably, HBV viraemia was efficiently lowered (∼2-log) and human interferon-stimulated genes similarly induced in all three HBV/HDV-infected mouse groups receiving pegIFNα. Genome sequencing revealed highly conserved ribozyme and L-hepatitis D antigen post-translational modification sites among all three isolates. Conclusions: Our comparative study indicates the ability of pegIFNα to lower HDV loads in stably infected human hepatocytes in vivo and the existence of complex virus-specific determinants of IFNα responsiveness. Impact and implications: Understanding factors counteracting HDV infections is paramount to develop curative therapies. We compared the responsiveness of three different cloned HDV strains to pegylated interferon alpha in chronically infected mice. The different responsiveness of these HDV isolates to treatment highlights a previously underestimated heterogeneity among HDV strains.

KIAA0317 regulates SOCS1 stability to ameliorate colonic inflammation.

Dysregulated cytokine signalling is a hallmark of inflammatory bowel diseases. Inflammatory responses of the colon are regulated by the suppressor of cytokine signalling (SOCS) proteins. SOCS1 is a key member of this family, and its function is critical in maintaining an appropriate inflammatory response through the JAK/STAT signalling pathway. Dysregulation of SOCS1 protein has been identified as a causal element in colonic inflammatory diseases. Despite this, it remains unclear how SOCS1 protein is regulated. Here, we identify that SOCS1 protein is targeted for degradation by the ubiquitin proteasome system, mediated by the E3 ubiquitin ligase KIAA0317 during experimental colonic inflammation. We characterize the mechanism of protein-protein interaction and ubiquitin conjugation to SOCS1 and demonstrate that the modulation of SOCS1 protein level leads to stark effects on JAK/STAT inflammatory signalling. Together, these results provide insight into the regulation of colonic inflammation through a new mechanism of ubiquitin-based control of SOCS1 protein.

Secretoglobin 3A2 protects lung from developing cigarette smoke-induced pulmonary emphysema.

Secretoglobin (SCGB) 3A2 is a bioactive molecule exhibiting various functions such as improving allergic airway inflammation and pulmonary fibrosis and promoting bronchial branching and proliferation during lung development. To determine if and how SCGB3A2 is involved in chronic obstructive pulmonary disease (COPD), a multifactorial disease with both airway and emphysematous lesions, a COPD mouse model was created by exposing Scgb3a2-deficient (KO), Scgb3a2-lung-specific overexpressing (TG), and wild type (WT) mice to cigarette smoke (CS) for 6 months. The KO mice showed loss of lung structure under control condition, and CS exposure resulted in more expansion of airspace and destruction of alveolar wall than WT mouse lungs. In contrast, TG mouse lungs showed no significant changes after CS exposure. SCGB3A2 increased the expression and phosphorylation of signal transducers and activators of transcription (STAT)1 and STAT3, and the expression of α1-antitrypsin (A1AT) in mouse lung fibroblast-derived MLg cells and mouse lung epithelial-derived MLE-15 cells. In MLg cells, A1AT expression was decreased in Stat3-knockdown cells, and increased upon Stat3 overexpression. STAT3 formed a homodimer when cells were stimulated with SCGB3A2. Chromatin immunoprecipitation and reporter assays demonstrated that STAT3 binds to specific binding sites on the Serpina1a gene encoding A1AT and upregulates its transcription in lung tissues of mice. Furthermore, nuclear localization of phosphorylated STAT3 upon SCGB3A2 stimulation was detected by immunocytochemistry. These findings demonstrate that SCGB3A2 protects the lungs from the development of CS-induced emphysema by regulating A1AT expression through STAT3 signaling.

The research development of STAT3 in hepatic ischemia-reperfusion injury.

Ischemia-reperfusion injury (IRI) is a common complication of surgery, which can cause rapid deterioration of the liver function, increase the risk of graft rejection, and seriously affect the prognosis of patients. The signal transducer and activator of transcription 3 (STAT3) protein has been implicated in pathogenesis of IRI. STAT3 influences the mitochondria through multiple pathways and is also involved in apoptosis and other forms of programmed cell death. STAT3 is associated with Janus kinase (JAK), phosphoinositide-3 kinase (PI3K), and heme oxygenase-1 (HO-1) in liver IRI. The STAT3 pathway plays a dual role in IRI as it can also regulate lipid metabolism which may have potential for treating IRI fatty liver. In this review, we summarize research on the function of STAT3 in liver IRI to provide references for its application in the clinic.

A Dual-Responsive STAT3 Inhibitor Nanoprodrug Combined with Oncolytic Virus Elicits Synergistic Antitumor Immune Responses by Igniting Pyroptosis.

Immune checkpoint blockade (ICB) therapy shows excellent efficacy against malignancies; however, insufficient tumor immunogenicity and the immunosuppressive tumor microenvironment (TME) are considered as the two major stumbling blocks to a broad ICB response. Here, a combinational therapeutic strategy is reported, wherein TME-reactive oxygen species/pH dual-responsive signal transducers and activators of transcription 3 inhibitor nanoprodrugs MPNPs are combined with oncolytic herpes simplex virus 1 virotherapy to synergistically ignite pyroptosis for enhancing immunotherapy. MPNPs exhibit a certain level of tumor accumulation, reduce tumor cell stemness, and enhance antitumor immune responses. Furthermore, the simultaneous application of oncolytic viruses (OVs) confers MPNPs with higher tumor penetration capacity and remarkable gasdermin-E-mediated pyroptosis, thereby reshaping the TME and transforming "cold" tumors into "hot" ones. This "fire of immunity" strategy successfully activates robust T-cell-dependent antitumor responses, potentiating ICB effects against local recurrence and pulmonary metastasis in preclinical "cold" murine triple-negative breast cancer and syngeneic oral cancer models. Collectively, this work may pave a new way and offer an unprecedented opportunity for the combination of OVs with nanomedicine for cancer immunotherapy.

Erythrocyte membrane-associated protein inhibiting Th17 cell differentiation via IL-6 / STAT3 / ROR-γt signaling pathway in experimental autoimmune encephalomyelitis mice / 解剖学报

Objective To explore the effect of exogenous and endogenous erythrocyte membrane-associated protein (ERMAP) on helper T cell 17 (Th17) cell differentiation through interleukin 6 / signal transducers and activators of transcription 3 / retionoid-related orphan nuclear receptor-γt(IL-6 / STAT3 / ROR-γt) signal pathway in the mouse model of experimental autoimmune encephalomyelitis (EAE) . Methods Using flow cytometry to verify the function of ERMAP-Ig fusion protein at different concentrations; Agarose gel electrophoresis was performed to identify ERMAP knockout mice. Flow cytometry was performed to detect the effect of ERMAP-Ig fusion protein on Th17 cell differentiation in vitro. Forty 6-week-old normal C57BL / 6 mice were randomly divided into 2 groups to establish EAE models, control-Ig and ERMAP-Ig groups, with 20 mice in each group; Clinical scores were recorded; Flow cytometry was performed to detect Th17 cell differentiation in EAE mice in vivo. Forty 6-week-old identified wild-type and ERMAP knockout mice were divided into 2 groups to establish EAE models. Identified wild-type and ERMAP knockout mice were divided into 2 groups to establish EAE models, ERMAP

Porphyromonas gingivalis enhances the proliferation of colorectal cancer Caco-2 cells via the JAK2-STAT3 pathway / 口腔疾病防治

Objective @# To investigate the effect of pathogenic bacterium-Porphyromonas gingivalis (P.g) on the proliferation and inflammatory factor expression of human colorectal cancer Caco-2 cells, to determine whether the Janus kinase 2-signal transducers and activators of transcription 3 (JAK2-STAT3) pathway is involved in the regulation of Caco-2 cell proliferation by P.g and to provide an experimental basis for further exploring the relationship between P.g and colorectal cancer. @*Methods @# Caco-2 cells were cultured in vitro, and P.g at different multiplicities of infection (MOIs) (0, 1, 10, 25) was selected to stimulate for 12, 24 and 48 h. The effect of P.g on the proliferation of Caco-2 cells was detected by CCK8. The stimulation time was set as 12, 24 and 48 h. MOI=0 was the control group, and MOI=1, 10 and 25 comprised the experimental group. qRT-PCR and Western blot were used to detect the changes in interleukin-6 (IL-6), interleukin-10(IL-10), JAK2 and STAT3 gene and protein (phosphorylated protein) levels in each group. @*Results @# After P.g infection of Caco-2 cells, P.g had a sustained stimulatory effect on the cells for 12, 24 and 48 h at MOI=1 and MOI=10 compared with the control group. Compared with that in the control group, the expression of pro-inflammatory factor IL-6 and related proliferative pathway protein JAK2 and STAT3 in Caco-2 cells with P.g infection increased in a concentration- and time-dependent manner (P<0.05). Additionally, the expression of IL-10, an anti-inflammatory factor, in Caco-2 cells infected with P.g decreased (P<0.05). After the addition of the JAK2 inhibitor AZ960, the proliferation of Caco-2 cells infected with P.g decreased, and the mRNA expression of STAT3 and JAK2 and the protein expression of p-STAT3 and p-JAK2 decreased (P<0.05). @*Conclusion @#P.g can promote the proliferation of the colorectal cancer cell line Caco-2, and the effect of P.g on Caco-2 cells may promote cell proliferation through the JAK2-STAT3 pathway while promoting the expression of the proinflammatory factor IL-6 and inhibiting the expression of the anti-inflammatory factor IL-10, creating an inflammatory environment conducive to cell proliferation, which may be the mechanism by which P.g affects the proliferation of Caco-2 cells.

Anti-Inflammatory Effects of the LK5 Herbal Complex on LPS- and IL-4/IL-13-Stimulated HaCaT Cells and a DNCB-Induced Animal Model of Atopic Dermatitis in BALB/c Mice.

Atopic dermatitis (AD) is a chronic inflammatory skin disease influenced by a complex interplay of genetic and environmental factors. The activation of the JAK-STAT pathway increases the expression of inflammatory cytokines such as IL-4 and IL-13, further deteriorating AD. Therefore, for the treatment of AD, the JAK-STAT pathway is emerging as a significant target, alongside inflammatory cytokines. This study investigates the potential therapeutic effects of a novel herbal complex, LK5, composed of Scutellaria baicalensis, Liriope platyphylla, Sophora flavescens, Dictammus dasycarpus, and Phellodendron schneider, known for their anti-inflammatory and immune-modulating properties. We examined the anti-inflammatory and anti-AD effects of the LK5 herbal complex in HaCaT cells stimulated by LPS and IL-4/IL-13, as well as in a mouse model of AD induced by DNCB. In HaCaT cells stimulated with LPS or IL-4/IL-13, the LK5 herbal complex demonstrated anti-inflammatory effects by inhibiting the expression of inflammatory cytokines including TNF-α, IL-6, and IL-1ß, and downregulating the phosphorylation of STAT proteins. In a murine AD-like model induced by DNCB, administration of the LK5 herbal complex significantly ameliorated clinical symptoms, including dermatitis, ear thickness, and TEWL. Histological analysis revealed a reduction in epidermal thickness and mast cell infiltration. The LK5 herbal complex also inhibited pruritus induced by compound 48/80. Furthermore, the LK5 herbal complex treatment significantly decreased the levels of inflammatory cytokines such as TSLP, IL-6, and IgE in plasma and ear tissue of AD-induced mice. These findings suggest that the LK5 herbal complex may modulate the immune response and alleviate AD symptoms by inhibiting STAT pathways.

Tofacitinib Inhibits STAT Phosphorylation and Matrix Metalloproteinase-3, -9 and -13 Production by C28/I2 Human Juvenile Chondrocytes.

Purpose: This in vitro study was designed to determine the effect of the pan-Janus kinase inhibitor, Tofacitinib, on basal and interleukin-6 (IL-6)-induced signal transducers and activators of transcription (STAT) phosphorylation and matrix metalloproteinase (MMP) gene expression and MMP production by C28/I2 human chondrocytes. Methods: C28/I2 chondrocytes were grown to a confluent high-density and treated either with recombinant human IL-6 (rhIL-6; 10-20ng/mL) or maintained in the basal state for up to 60 min. MMP gene expression was determined using RT-PCR and MMP production by semi-quantitative immunohistochemistry. The effect of IL-6 with or without Tofacitinib on activation of STAT proteins was determined from quantitative Western blots. Results: C28/I2 chondrocytes produced STAT1, STAT3 and STAT5AB which were phosphorylated (p) following treatment with rhIL-6 for 30 min. Tofacitinib (2.5nM-100nM) decreased rhIL-6-induced activation of STAT1, STAT3, and STAT5AB as well as decreasing the expression of MMP3 and MMP13 but not MMP9, MMP1 or MMP2. In addition, Tofacitinib (50nM) reduced the number of rhIL-6-induced MMP3-, and MMP13- antibody-positive C28/I2 chondrocytes. However, Tofacitinib did decrease the number of MMP9-antibody-positive C28/I2 chondrocytes. Conclusion: Taken together, these data showed that Tofacitinib, a pan-JAK small molecule inhibitor employed for the medical therapy of rheumatoid arthritis was a potent inhibitor of rhIL-6-induced STAT phosphorylation that appeared to be coupled to the inhibition of MMP-3, -9 and -13 production by C28/I2 chondrocytes.

Regulatory Effect of JAK2/STAT3 on the Immune Function of Endotoxin-tolerant Dendritic Cells and its Involvement in Acute Liver Failure.

Background and Aims: Acute liver failure (ALF) is a potentially fatal clinical syndrome with no effective treatment. This study aimed to explore the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway in modulating the phenotype and immune function of endotoxin-tolerant dendritic cells (ETDCs). In addition, we explored the use of EDTCs in an experimental model of ALF and investigated the associated mechanisms. Methods: In the in vitro experiment, ETDCs were transfected with adenovirus to induce SOCS1+/+ETDCs and SOCS1-/-ETDCs. Thereafter, costimulatory molecules and mixed lymphocyte reaction were assessed. Experimental mice were randomly divided into normal control, ALF, ALF+mock-ETDCs, ALF+SOCS1+/+ETDCs, ALF+AG490, and ALF+AG490+SOCS1+/+ETDCs groups. We examined the therapeutic effect of adoptive cellular immunotherapy by tail-vein injection of target ETDCs 12 h before ALF modeling. AG490, a JAK2/STAT3 inhibitor, was used in the in vivo experiment to further explore the protective mechanism of SOCS1+/+ETDCs. Results: Compared with control ETDCs, SOCS1+/+ETDCs had lower expression of costimulatory molecules, weaker allostimulatory ability, lower levels of IL-6 and TNF-α expression and higher IL-10 secretion. SOCS1-/-ETDCs showed the opposite results. In the in vivo experiments, the ALF+SOCS1+/+ETDCs and ALF+AG490+SOCS1+/+ETDCs groups showed less pathological damage and suppressed activation of JAK2/STAT3 pathway. The changes were more pronounced in the ALF+AG490+SOCS1+/+ETDCs group. Infusion of SOCS1+/+ETDCs had a protective effect against ALF possibly via inhibition of JAK2 and STAT3 phosphorylation. Conclusions: The SOCS1 gene had an important role in induction of endotoxin tolerance. SOCS1+/+ETDCs alleviated lipopolysaccharide/D-galactosamine-induced ALF by downregulating the JAK2/STAT3 signaling pathway.

Ruxolitinib inhibits cytokine production by human lung macrophages without impairing phagocytic ability.

Background: The Janus kinase (JAK) 1/2 inhibitor ruxolitinib has been approved in an indication of myelofibrosis and is a candidate for the treatment of a number of inflammatory or autoimmune diseases. We assessed the effects of ruxolitinib on lipopolysaccharide (LPS)- and poly (I:C)-induced cytokine production by human lung macrophages (LMs) and on the LMs' phagocytic activity. Methods: Human LMs were isolated from patients operated on for lung carcinoma. The LMs were cultured with ruxolitinib (0.5 × 10-7 M to 10-5 M) or budesonide (10-11 to 10-8 M) and then stimulated with LPS (10 ng·ml-1) or poly (I:C) (10 µg·ml-1) for 24 h. Cytokines released by the LMs into the supernatants were measured using ELISAs. The phagocytosis of labelled bioparticles was assessed using flow cytometry. Results: Ruxolitinib inhibited both the LPS- and poly (I:C)-stimulated production of tumor necrosis factor alpha, interleukin (IL)-6, IL-10, chemokines CCL2, and CXCL10 in a concentration-dependent manner. Ruxolitinib also inhibited the poly (I:C)- induced (but not the LPS-induced) production of IL-1ß. Budesonide inhibited cytokine production more strongly than ruxolitinib but failed to mitigate the production of CXCL10. The LMs' phagocytic activity was not impaired by the highest tested concentration (10-5 M) of ruxolitinib. Conclusion: Clinically relevant concentrations of ruxolitinib inhibited the LPS- and poly (I:C)-stimulated production of cytokines by human LMs but did not impair their phagocytic activity. Overall, ruxolitinib's anti-inflammatory activities are less intense than (but somewhat different from) those of budesonide-particularly with regard to the production of the corticosteroid-resistant chemokine CXCL-10. Our results indicate that treatment with a JAK inhibitor might be a valuable anti-inflammatory strategy in chronic obstructive pulmonary disease, Th1-high asthma, and both viral and non-viral acute respiratory distress syndromes (including coronavirus disease 2019).

ß2 Integrins on Dendritic Cells Modulate Cytokine Signaling and Inflammation-Associated Gene Expression, and Are Required for Induction of Autoimmune Encephalomyelitis.

Heterodimeric ß2 integrin surface receptors (CD11a-d/CD18) are specifically expressed by leukocytes that contribute to pathogen uptake, cell migration, immunological synapse formation and cell signaling. In humans, the loss of CD18 expression results in leukocyte adhesion deficiency syndrome (LAD-)1, largely characterized by recurrent severe infections. All available mouse models display the constitutive and ubiquitous knockout of either α or the common ß2 (CD18) subunit, which hampers the analysis of the cell type-specific role of ß2 integrins in vivo. To overcome this limitation, we generated a CD18 gene floxed mouse strain. Offspring generated from crossing with CD11c-Cre mice displayed the efficient knockdown of ß2 integrins, specifically in dendritic cells (DCs). Stimulated ß2-integrin-deficient splenic DCs showed enhanced cytokine production and the concomitantly elevated activity of signal transducers and activators of transcription (STAT) 1, 3 and 5, as well as the impaired expression of suppressor of cytokine signaling (SOCS) 2-6 as assessed in bone marrow-derived (BM) DCs. Paradoxically, these BMDCs also showed the attenuated expression of genes involved in inflammatory signaling. In line, in experimental autoimmune encephalomyelitis mice with a conditional DC-specific ß2 integrin knockdown presented with a delayed onset and milder course of disease, associated with lower frequencies of T helper cell populations (Th)1/Th17 in the inflamed spinal cord. Altogether, our mouse model may prove to be a valuable tool to study the leukocyte-specific functions of ß2 integrins in vivo.