MyD88 Signaling Pathway Research Articles

Phosphorothioate-linked guanine/cytosine-based stem-loop oligonucleotides induce the extracellular release of mitochondrial DNA from peritoneal B1a cells

It has been previously demonstrated that phosphorothioate-linked GpC-based stem-loop oligonucleotides (GC-SL ODN) induce the release of mitochondrial DNA (mtDNA) from chronic lymphocytic leukemia (CLL) B cells. Although CLL B cells are believed to originate from CD5+ B cells because of their phenotypic similarities, it remains unclear whether GC-SL ODN can stimulate CD5+ B1 cells to secrete mtDNA. To explore this possibility, we compared the frequency of the mtDNA-producing population among peritoneal cells after GC-SL ODN treatment. We found that mtDNA-releasing cells are enriched for peritoneal CD19+ B cells upon GC-SL ODN challenge. Among peritoneal CD19+ B cells, the CD5+ B1a subpopulation was a primary cellular source of mtDNA secretion in GC-SL ODN-elicited immune responses. GC-SL ODN-stimulated mtDNA release by B1a cells was positively regulated by MyD88 and TRIF signaling pathways. In vivo GC-SL ODN treatment increased lipopolysaccharide-induced activation of innate immune cells such as NK cells, suggesting the immune-enhancing effects of mtDNA secretion. Furthermore, the loop size formed by GC-SL ODNs was a critical factor in inducing mtDNA release by B1a cells. Taken together, our results identified GC-SL ODN as promising biomaterials for enhancing immune responses.

Impact of Long Non-Coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 on the Susceptibility of High Glucose-Treated Cardiomyocytes to Hypoxia/Reoxygenation

To estimate the effect of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on susceptibility of high glucose (HG)-treated cardiomyocytes (CMs) to hypoxia/reoxygenation (H/R). Forty healthy rats were assigned to the control, diabetes mellitus (DM), DM + ischemia/reperfusion injury (IRI) control, and DM IRI groups (n = 10 for each group). Rat CMs (H9C2) were subjected to HG and H/R treatments. LncRNA MALAT1 and cyclic-AMP responsive element modulator (CREM) mRNA levels were measured using quantitative polymerase chain reaction, and protein levels of CREM, myeloid differentiation primary response protein 88 (MyD88), interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor associated factor 6 (TRAF6), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were quantified using western blotting. Flow cytometry was applied for detection of apoptosis, and a cell viability analyzer determined the number of living cells. IRI induced myocardial apoptosis and elevated lncRNA MALAT1, CREM, and MyD88/IRAK1/TRAF6 levels in DM group mice. In H9C2 cells, HG treatment downregulated CREM expression, which resulted in the downregulation of lncRNA MALAT1 expression, reducing the susceptibility to H/R, increasing cell viability and apoptosis, decreasing the activity of the MyD88/IRAK1/TRAF6 signaling pathway, and suppressing TNF-α and IL-6 expression. LncRNA MALAT1 regulates the susceptibility of HG-treated CMs to H/R through the MyD88 signaling pathway.

MYD88 Mutations: Transforming the Landscape of IgM Monoclonal Gammopathies.

The MYD88 gene has a physiological role in the innate immune system. Somatic mutations in MYD88, including the most common L265P, have been associated with the development of certain types of lymphoma. MYD88L265P is present in more than 90% of patients with Waldenström’s macroglobulinemia (WM) and IgM monoclonal gammopathy of undetermined significance (IgM-MGUS). The absence of MYD88 mutations in WM patients has been associated with a higher risk of transformation into aggressive lymphoma, resistance to certain therapies (BTK inhibitors), and shorter overall survival. The MyD88 signaling pathway has also been used as a target for specific therapies. In this review, we summarize the clinical applications of MYD88 testing in the diagnosis, prognosis, follow-up, and treatment of patients. Although MYD88L265P is not specific to WM, few tumors present a single causative mutation in a recurrent position. The role of the oncogene in the pathogenesis of WM is still unclear, especially considering that the mutation can be found in normal B cells of patients, as recently reported. This may have important implications for early lymphoma detection in healthy elderly individuals and for the treatment response assessment based on a MYD88L265P analysis.

Effect of Tritrichomonas foetus, Tf-31 (a cattle isolate) and Tff6 (a feline isolate) on TLR signaling pathway in cervical epithelial cells.

Abstract Bovine trichomonosis is caused by Tritrichomonas foetus, which is widely prevalent in 33 US states, and is a reportable disease due to potential huge economic losses to cattle industry. T. foetus also causes chronic large-bowel diarrhoea in cats, complicated not only by its chronicity but for its difficulty to treat, with few registered or effective products available. T. foetus persistently colonize the lower genital tract of bulls but usually do not cause either major clinical signs or inflammation while vaginal inflammation is a common disease of the dairy cows’ reproductive tract. Mechanisms of immune response to this pathogen are poorly studied. This study for the first time, reports the effect of T. foetus; Tf-31-cattle isolate and Tff6-cat isolate, on activation of toll-like receptors (TLRs) and inflammatory response in vaginal epithelial cells. The expression levels of serial effectors related to the TLRs-MyD88/NF-κB signaling pathway (TLR2, TLR4, MyD88, NF-κB, IL-1β, IL-6, TNF-α, and IL-10) were measured with real-time polymerase chain reaction (RT-PCR), ELISA, and Western blot analyses. Of the 6 cell-membrane TLRs tested, TLR2 and TLR4 were activated by cells, as noted by increased mRNA expression levels of TLR2 and TLR4 in both Tf31 and Tff6 treated cervical epithelial cells relative to control cells. ELISA assays showed up-regulation on IL-10, both in Tf-31 and Tff6 treated epithelial cells. Treatment with inhibitors of MyD88 signaling pathway abolished the upregulation of downstream cytokines. These data indicate that T. foetus isolates activate TLR-MyD88 signaling pathway to induce innate immune response. However, further detailed in vitro and in vivo studies are required to confirm these findings. Supported by Biology department

Gastroprotective effect of an active ingredients group of Lindera reflexa Hemsl. On Ethanol-Induced gastric ulcers in Rats: Involvement of VEGFR2/ERK and TLR-2/Myd88 signaling pathway

Lindera reflexa Hemsl. (LR) has been used for the treatment of gastrointestinal disorders. The present study was carried out to investigate the gastroprotective effect of an active ingredients group of Lindera reflexa Hemsl. (LRG) on ethanol-induced gastric ulcer in rats and its possible mechanisms. The ulcer area was measured, and samples of gastric tissue were taken for histochemical, pathological, and biochemical analyses. Pretreatment with LRG protected the gastric mucosa as seen by reduction the GUI and gastric juice volume, regulated gastric acid secretion. LRG counteracted the ethanol-induced oxidative stress by increasing the levels of depleted SOD and CAT as well as significantly attenuating the lipid peroxidation by reducing the levels of MDA and MPO. LRG also reduced release of inflammatory mediator TNF-α, increased the content of PGE2 and inhibited MTL secretion. Immunofluorescence and Western blot analyses confirmed that the co-localization of TLR-2 and MyD88 protein in the gastric mucosa of LRG-treated rats was significantly lower than that of rats with gastric ulcers. Furthermore, LRG also modulated the expression of Ki-67 antigens. LRG markedly increased the expression of phosphorylated form of extracellular signal-regulated kinaseVEGFR2, ERK1/2, AKT and p38, thereby protecting the gastric mucosa. These findings indicated that the gastroprotective effect of LRG is attributable to its antioxidant, anti-inflammatory, and antisecretory properties. In addition, LRG can ameliorate ethanol-induced gastric ulcers in rats by regulating the VEGFR2/ERK and TLR-2/MyD88 signaling pathways.

PM2.5 aggravates airway inflammation in asthmatic mice: activating NF-κB via MyD88 signaling pathway

ABSTRACT The role of PM2.5 in the bronchial asthma remains unclear. In this study, the deficient mice of TLR4-/-, TLR2-/- and MyD88 -/- were used to establish asthma model. The effects of PM2.5 on the inflammatory response in lung tissue of these mice were observed. PM2.5 increased alveolar macrophages and neutrophils, up-regulated the IL-12 and KC expression in WT mice, but down-regulated their levels in TLR2 -/-, TLR4 -/- and MyD88 -/- mice. OVA+PM2.5 stimulated neutrophil count in WT mice, but it decreased in TLR2 -/- and TLR4 -/- mice. OVA+PM2.5 also increased the Eotaxin, IL-5, IL-13 and MCP-3 expression levels, and OVA specific IgE and IgG1 in serum also increased in WT group. PM2.5 may activate NF-κB through the TLR2/TLR4/MyD88 signaling pathway and aggravate allergic inflammation of lung in asthmatic mice. The microelements in PM2.5 granules, such as lipopolysaccharide, may be an important factor in the high incidence of asthma.

CALR-TLR4 Complex Inhibits Non-Small Cell Lung Cancer Progression by Regulating the Migration and Maturation of Dendritic Cells.

BackgroundLung cancer is a common malignant tumor that threatens human life and is associated with high morbidity and mortality rates. Calreticulin (CALR) is a antigen characteristic of immunogenic cell death in non-small cell lung cancer (NSCLC), which is closely related to anti-tumor immunity, but its specific mechanism in anti-tumor immunity remains unclear.MethodsImmunohistochemical staining was performed to detect the expression of CALR and dendritic cell-lysosome-associated membrane glycoprotein (DC-LAMP) in NSCLC tissues. The cell supernatant was used to induce migration and maturation of dendritic cells (DCs). Western blot and real-time PCR were used to investigate the corresponding molecule expression in the CALR-Toll-like receptor 4 (TLR4)-MyD88 signaling pathway. In vivo experiments were conducted to evaluate the role of mCALR in lung cancer progression.ResultsThe expression of CALR on NSCLC cell membrane (mCALR) and DC infiltration in NSCLC were positively correlated and were closely related to the prognosis of NSCLC patients. Moreover, mCALR facilitated the migration and maturation of DCs by activating CALR-TLR4-MyD88 signaling and increasing the secretion of TNFα and CCL19, which was inhibited by the loss of TLR4. In vivo experiments demonstrated that mCALR inhibited lung cancer progression by facilitating DC infiltration in lung cancer tissues.ConclusionOur study explores the function and mechanism of the CALR-TLR4 complex in DC migration and maturation and investigates the inhibitory effect of the CALR-TLR4 complex on lung cancer progression, providing a theoretical basis and ideas for immunotherapy of NSCLC.

Effect of C21 steroidal glycoside of Cynanchum auriculatum on liver and kidney fibrosis through TLR4 pathway

The liver and kidney fibrosis model was established by thioacetamide(TAA) and unilateral ureteral obstruction(UUO) in SD rats. The rats were randomly divided into three groups: model group, low and high-dose groups of C21 steroidal glycosides of Cynanchum auriculatum. Another blank control group was set. Four weeks later, serum was taken to detect the biochemical indexes of liver and kidney function. Urine protein and urine creatinine were detected by kits. Liver and kidney tissue samples were stained with HE and Masson staining, and hydroxyproline content was detected. Western blot was used to detect expressions of fibrotic proteins, inflammatory factors and TLR4 signaling pathways, so as to observe the preventive and therapeutic effects of C21 steroidal glycosides from C. auriculatum on hepatic and renal fibrosis and explore its molecular mechanism. Four weeks later, serum biochemical results showed that liver and kidney functions were seriously damaged, and pathological sections showed that inflammatory cell infiltration, decrease of parenchymal cells, and increase of interstitial fibrosis in liver and kidney tissues. The results showed that low and high doses(150, 300 mg·kg~(-1)) of C21 steroidal glycosides could significantly reduce the collagen deposition and the pathological changes of liver and kidney fibrosis compared with the model group. At the same time, we found that the expression levels of TLR4 and MyD88 signaling pathway proteins were significantly increased in the liver and kidney tissues of the model group, and a large number of NF-κB signaling pathway proteins migrated into the nucleus. On the contrary, the expression levels of TLR4, MyD88 signaling pathway proteins and the nuclear migration of NF-κB were significantly inhibited in the low and high dose groups of C21 steroidal glycosides from C. auriculatum. Therefore, it was speculated that the mechanism of C21 steroidal glycoside for preventive and therapeutic effect on hepatic and renal fibrosis was related to inhibit TLR4/MYD88/NF-κB inflammatory pathway, thus preventing hepatic and renal fibrosis.

Anthocyanins from purple maize (Zea mays L.) downregulate lipopolysaccharide-induced peritonitis in mice by modulating the MyD88 signaling pathway

BackgroundPurple maize is a rich source of anthocyanins, known to exhibit bioactive health benefits. However, their potential anti-inflammatory activity is poorly known. MethodsAnthocyanin extracts (AE) from purple maize was characterized by LC-ESI-MS/MS platform. In vivo experimental model, AE (doses of 2 and 4 mg Antho/100 g body weight) was orally administered at two different times: 30 min before and 1 h after LPS intraperitoneal inflammatory stimulus. Peritoneal exudates were withdrawn 3 h after LPS injection, and leukocyte influx, cytokines and PGE2 were quantified. COX-2, TLR4, and MyD88 protein expression were evaluated by Western blotting. ResultsFourteen phenolic compounds were identified in AE, with cyanidin-3-O-glucoside and its acylated form as the major anthocyanins in both baths of purple maize extract evaluated. AE treatment significantly reduced leukocyte migration, mainly the polymorphonuclear leukocytes (p < 0.05) in the peritoneal exudates when administered 30 min and 1 h after LPS injection, at both doses. LPS-induced pro-inflammatory cytokines (IL-1β, IL-6, IL-10, KC, and CCL2) were inhibited (p < 0.05) by pre and posttreatments with AE (p < 0.05). Similarly, AE treatments suppressed LPS-induced COX-2 protein expression and decrease PGE2 levels in the peritoneal exudates (p < 0.05). Additionally, AE at the higher dose downregulated LPS-induced MyD88 expression (p < 0.05) when administered before and after LPS intraperitoneal injection. Under the experimental conditions, the constitutive expression of TLR4 in leukocytes was not modified. ConclusionOur findings evidence for the first time that AE from purple maize provide preventive and anti-inflammatory beneficial activity by downregulating key acute inflammatory components induced by LPS injection, by modulating MyD88 signaling pathways.

Exosomes derived from mycobacterium tuberculosis-infected MSCs induce a pro-inflammatory response of macrophages.

Tuberculosis (TB) is a common infectious disease caused by Mycobacterium tuberculosis (M.tb), and macrophages serve as the primary natural host of M.tb. Mesenchymal stem cells (MSCs)-derived exosomes play an essential role in inflammatory responses. This study aimed to determine the role of exosomes derived from M.tb-infected MSCs (Exo-MSCs-M.tb) on macrophages in vitro and in vivo and the underlying mechanisms. Here, we demonstrated that M.tb infection promoted the production of Exo-MSCs-M.tb, but did not influence MSCs proliferation. Exo-MSCs-M.tb were taken up by macrophages and then induced the pro-inflammatory response of macrophages through elevating the production of TNF-α, RANTES, and iNOS. Also, pro-inflammatory response induced by Exo-MSCs-M.tb displayed a time-dependent pattern in macrophages, in which the highest level of inflammatory response was observed at 72 hours post-infection of MSCs. In addition, the effect of Exo-MSCs-M.tb was mediated through TLR2/4 and MyD88 signaling pathways. Furthermore, Exo-MSCs-M.tb could induce the pro-inflammatory response in mice in vivo, and exosomes isolated from Exo-MSCs-M.tb-treated mice could also promote the pro-inflammatory response. Taken together, these results indicate that Exo-MSCs-M.tb induced the pro-inflammatory response of macrophages through TLRs signaling. This study provides new insight into the potential of MSCs-derived exosomes for the treatment of TB.

Immunohistochemical Expression of Myeloid Differentiation Adaptor Protein-88(MYD-88 )and Toll like Receptor (TLR-4) in Human Leiomyomas

Leiomyomas are the most common benign tumor of the female reproductive tract. The aim of this study wasto explore the role of TLR4/ MYD-88signaling pathway in the pathogenesis of leiomyomas. Benign natureand smooth muscle origination of leiomyomas was easily documented via histological examination, in thiscross-sectional study of 20 conventional leiomyomas cases TLR4/ MYD-88 antibody status was positive in90% for TLR-4 and in 95% for MYD-88 of leiomyomas. Leiomyomas were stained with TLR4/ MYD-88marker more than those in normal myometrium cases (P&lt;0.001). In conclusion leiomyomas growth may beassociated with TLR4 and MyD88 expression

Extracellular histones stimulate collagen expression in vitro and promote liver fibrogenesis in a mouse model via the TLR4-MyD88 signaling pathway.

BACKGROUNDLiver fibrosis progressing to liver cirrhosis and hepatic carcinoma is very common and causes more than one million deaths annually. Fibrosis develops from recurrent liver injury but the molecular mechanisms are not fully understood. Recently, the TLR4-MyD88 signaling pathway has been reported to contribute to fibrosis. Extracellular histones are ligands of TLR4 but their roles in liver fibrosis have not been investigated.AIMTo investigate the roles and potential mechanisms of extracellular histones in liver fibrosis.METHODS In vitro, LX2 human hepatic stellate cells (HSCs) were treated with histones in the presence or absence of non-anticoagulant heparin (NAHP) for neutralizing histones or TLR4-blocking antibody. The resultant cellular expression of collagen I was detected using western blotting and immunofluorescent staining. In vivo, the CCl4-induced liver fibrosis model was generated in male 6-week-old ICR mice and in TLR4 or MyD88 knockout and parental mice. Circulating histones were detected and the effect of NAHP was evaluated.RESULTSExtracellular histones strongly stimulated LX2 cells to produce collagen I. Histone-enhanced collagen expression was significantly reduced by NAHP and TLR4-blocking antibody. In CCl4-treated wild type mice, circulating histones were dramatically increased and maintained high levels during the duration of fibrosis-induction. Injection of NAHP not only reduced alanine aminotransferase and liver injury scores, but also significantly reduced fibrogenesis. Since the TLR4-blocking antibody reduced histone-enhanced collagen I production in HSC, the CCl4 model with TLR4 and MyD88 knockout mice was used to demonstrate the roles of the TLR4-MyD88 signaling pathway in CCl4-induced liver fibrosis. The levels of liver fibrosis were indeed significantly reduced in knockout mice compared to wild type parental mice.CONCLUSIONExtracellular histones potentially enhance fibrogenesis via the TLR4–MyD88 signaling pathway and NAHP has therapeutic potential by detoxifying extracellular histones.

Meta-Analysis of Human Molecular Responses to Staphylococcus aureus

&#x0D; &#x0D; &#x0D; Objective: To compare the local and systematic transcriptional responses of human body to S. aureus or its components. Study Design: Meta-analysis of microarray data. Place and Duration of Study: The study was conducted at R.O. Perelman Department of Dermatology, The NYU Cancer Institute, NYU Langone Medical Center, New York, USA, from March 2015 to May 2015. Materials and Methods: Public repository “GEO Datasets” was searched using key term “Staphylococcus aureus” for data sets covering effects of S. aureus infection in Homo sapiens cells. The microarray data for immune cell responses to S. aureus was analyzed using Rank Prod, RMA Express and DAVID software. Results: The analysis has shown that S. aureus infection was responsible for inducing immunity, platelet activation, vasodilation, MyD88 dependent gene expression and cell cycle. It suppressed gene expression of normal cell processes, protein catabolism and apoptosis. Heat-inactivated S. aureus challenged the cell induced immunity, cell cycle, growth regulators, anti-apoptosis and anticoagulant genes, while suppressed the genes for adaptive immunity, carbohydrate synthesis and Myd88 dependent pathway. Furthermore, in the S. aureus-infected patients the genes for defense, innate immunity, solute receptors and anti-apoptotic processes were upregulated, whereas adaptive immunity and positive regulators of apoptosis were downregulated. Conclusion: MyD88 signaling pathway, ubiquitin mediated protein catabolism and IFNγ mediated cell death processes can be targeted for treatment against virulent S. aureus infections.&#x0D; &#x0D; &#x0D;

AspergillusfumigatusRecognition by Dendritic Cells Negatively Regulates Allergic Lung Inflammation through a TLR2/MyD88 Pathway

Aspergillus fumigatus is an opportunistic fungal pathogen responsible for a spectrum of clinical manifestations. Dendritic cells recognize pathogen-associated molecular patterns of Aspergillus via two main receptor families, Toll-like receptors (TLRs) and C-type lectin receptors (CLR). Here, the importance of TLR and CLR signaling in the regulation of T-helper cell type 2 (Th2) responses was analyzed using a mouse model based on the transfer of bone marrow-derived dendritic cells (BMDCs) pulsed with A. fumigatus conidia. BMDCs were generated from mice deficient in either MyD88 or MALT1 (mucosa-associated lymphoid tissue lymphoma translocation protein 1). Both the MyD88 and MALT1 signaling pathway in BMDCs contributed to the production of inflammatory cytokines induced by A. fumigatus conidia. Mice sensitized with MyD88-/- BMDCs pulsed in vitro with A. fumigatus conidia showed an exacerbated allergic inflammation, with stronger eosinophil recruitment in the BAL and higher Th2 cytokine production compared with mice sensitized with wild-type or MALT1-/- BMDCs. This exacerbation was not observed when MyD88-/- BMDCs were pulsed with Cladosporium sphaerospermum, a nonpathogenic mold. A lack of TLR2 signaling recapitulated the exacerbation of the A. fumigatus Th2 response observed in the absence of MyD88 signaling, whereas TLR2 agonist dampened the response induced with A. fumigatus and C. sphaerospermum conidia. IL-10 production by BMDCs in response to A. fumigatus was dependent on the expression of TLR2 and MyD88. IL-10-/- BMDCs exacerbated, whereas MyD88-/- BMDCs supplemented with exogenous IL-10 decreased the allergic pulmonary inflammation. These results indicate that TLR2/MyD88-specific recognition of PAMPs from A. fumigatus conidia can upregulate IL-10 production and downregulate lung eosinophilia and the development of a Th2 response.

Gene expression profiling in allopurinol-induced severe cutaneous adverse reactions in Vietnamese.

Aim: To examine gene expression in different clinical phenotypes of allopurinol-induced severe cutaneous adverse reactions (SCARs). Materials & methods: Gene expression profiling was performed using microarray on 11 RNA samples (four controls, threehypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms, four Stevens-Johnson syndrome/toxic epidermal necrolysis) followed by quantitative real-time PCR in a total of 11 SCARs patients and 11 controls. Results: The biological pathways which were significantly enriched in differentially expressed genesin Stevens-Johnson syndrome/toxic epidermal necrolysis compared with hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms patients included; cell surface interactions at the vascular wall, immunoregulatory interactions at the immunological synapse and MyD88 signaling pathways. Overexpression of miR146a occurred in allopurinol-tolerant HLA-B*58:01 carriers. Conclusion: Biological pathways are identified which appear to beimplicated in determining clinical phenotypes in allopurinol-induced SCARs. Overexpression of miR146a is potentially important for allopurinol tolerance in HLA-B*58:01 carriers.

Traditional Chinese Medicine Li-Zhong-Tang accelerates the healing of indomethacin-induced gastric ulcers in rats by affecting TLR-2/MyD88 signaling pathway

Ethnopharmacological relevanceLi-Zhong-Tang (LZT) is a well-known Chinese herbal formulation first described in one of traditional Chinese medicine (TCM) scriptures, Treatise on Febrile Diseases. LZT has been commonly prescribed for the treatment of various gastrointestinal diseases for over 1800 years, and has demonstrated pronounced therapeutic effects on patients with gastric ulcers. Aim of the studyThe present study aimed to scientifically evaluate protective effects of LZT on indomethacin (IND)-induced gastric injury in rats and to elucidate whether LZT exerts its gastro-protective effects via enhancing mucosal immunity by regulating TLR-2/MyD88 signaling pathway. Material and methodsGastric ulcers were induced in male Sprague-Dawley (SD) rats with a single oral dose of 150 mg/kg IND. Ulcer index (UI) and curative index (CI) were evaluated. Histopathological examinations were performed and microscopic score (MS) was macroscopically calculated. The volume of gastric juice, free acidity, total acidity, and gastric pH was measured. The gastroprotective and inflammatory biomarkers including levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and malondialdehyde (MDA) were determined. Expression levels of TLR-2 and MyD88 mRNA were assessed by qRT-PCR. The expression, distribution, and co-localization of TLR-2 and MyD88 protein were determined by Western blot, immunohistochemistry, and immunofluorescence, respectively. ResultsInduction of gastric ulcers in rats resulted in very significantly increased UI and elevated volume and acidity of gastric juice, which were markedly attenuated by LZT treatment. Microscopic examinations of the IND-induced gastric ulcers revealed severe gastric hemorrhagic necrosis, submucosal edema, and destruction of epithelial cells, which were significantly attenuated in LZT-treated rats. Moreover, treatment with LZT remarkably increased gastric mucosal levels of PGE2 and NO, and lowered highly elevated levels of TNF-α and MDA in gastric ulcerative rats. Mechanistically, LZT inhibited mRNA and protein expression of TLR-2 and MyD88 and enhanced immune function in gastric mucosa. Immunohistochemical analyses and immunofluorescent detection further confirmed a markedly decreased co-localization of TLR-2 and MyD88 protein in the gastric mucosa of LZT-treated rats as compared to that of gastric ulcerative rats. ConclusionsThese findings indicate that LZT alleviates serious gastric mucosal ulcerations induced by IND. Protective effects of LZT on gastric ulcers are believed to be associated with the intensification of the anti-oxidative defense system, mitigation of proinflammatory cytokines, stimulation of the production of cytoprotective mediators, and improvement of the mucosal immunity through TLR-2/MyD88 signaling pathway.

Exopolysaccharide from a commensal bacterium ameliorates aGVHD by decreasing alloreactive donor T cell activation

Abstract Acute graft versus host disease (aGVHD) is a severe and often lethal complication of allogeneic bone marrow transplantation (BMT). We found that mice injected with exopolysaccharide (EPS) secreted by a commensal bacterium, Bacillus subtilis, significantly improved survival, reduced weight loss and decreased production of systemic pro-inflammatory cytokines in GVHD mice. We utilized a novel biosensor mouse model to assess the activation of donor T cells in live mice during aGVHD and found that EPS inhibited the activation of alloreactive donor T cells. EPS also inhibited alloreactive T cell activation in mixed lymphocyte reactions (MLR) in vitro and this inhibition required DCs. Treating DCs with EPS led to upregulation of the inhibitory molecule PD-L1 and secretion of the anti-inflammatory cytokine IL-10, characteristic of inhibitory DCs. We determined that EPS induces inhibitory DCs through TLR4, signaling through both MyD88 and TRIF signaling pathways. The inhibition of alloreactive T cells by these inhibitory DCs is mediated by indoleamine 2,3-dioxygenase (IDO). We hypothesized that inhibition of alloreactive donor T cell activation in GVHD mice by EPS is also mediated by DCs and that EPS induces inhibitory DCs in vivo as well as in vitro. The data demonstrate the potential of EPS or EPS-treated DCs as novel reagents for preventing GVHD.

Type I Interferons Ameliorate Zinc Intoxication of Candida glabrata by Macrophages and Promote Fungal Immune Evasion.

SummaryHost and fungal pathogens compete for metal ion acquisition during infectious processes, but molecular mechanisms remain largely unknown. Here, we show that type I interferons (IFNs-I) dysregulate zinc homeostasis in macrophages, which employ metallothionein-mediated zinc intoxication of pathogens as fungicidal response. However, Candida glabrata can escape immune surveillance by sequestering zinc into vacuoles. Interestingly, zinc-loading is inhibited by IFNs-I, because a Janus kinase 1 (JAK1)-dependent suppression of zinc homeostasis affects zinc distribution in macrophages as well as generation of reactive oxygen species (ROS). In addition, systemic fungal infections elicit IFN-I responses that suppress splenic zinc homeostasis, thereby altering macrophage zinc pools that otherwise exert fungicidal actions. Thus, IFN-I signaling inadvertently increases fungal fitness both in vitro and in vivo during fungal infections. Our data reveal an as yet unrecognized role for zinc intoxication in antifungal immunity and suggest that interfering with host zinc homeostasis may offer therapeutic options to treat invasive fungal infections.

Antiulcerogenic Activity of Li-Zhong Decoction on Duodenal Ulcers Induced by Indomethacin in Rats: Involvement of TLR-2/MyD88 Signaling Pathway.

Background Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) often causes small intestinal ulcers in patients, but few effective drugs are currently available to manage such serious adverse events of NSAIDs. Li-Zhong decoction (LZD), a well-known traditional Chinese medicine (TCM) formula, is commonly prescribed for treatment of gastrointestinal diseases. The present study aimed to investigate the anti-ulcerogenic activity of LZD on indomethacin- (IND-) induced duodenal ulcer in rats. Mechanistic studies of action of LZD were focused on involvement of TLR-2/MyD88 signaling pathway. Methods Fifty male Sprague-Dawley (SD) rats were randomly and evenly divided into five groups: normal control, ulcer control (IND, 25 mg/kg), IND + esomeprazole (ESO, 4.17 mg/kg), and IND + low and high doses of LZD (3.75 and 7.50 g/kg). Macroscopic and histopathological examinations were performed for evaluation of ulcer index (UI), curative index (CI), and microscopic score (MS). Levels of duodenal inflammatory biomarkers and cytoprotective mediators including interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α (TNF-Results Gross and microscopic examinations of the IND-treated rats revealed severe duodenal hemorrhagic necrosis, inflammatory infiltration, villus destruction, and crypt abscess, while LZD-treated rats manifested these pathological events to a markedly lesser degree. LZD significantly decreased UI and MS, increased CI, preserved the integrity of the villus and crypt, and normalized the tissue architecture of the duodenum of rats. The elevated TNF-α (TNF-Conclusions Our data demonstrate that LZD protects the duodenal mucosa from IND-caused lesions, which is at least partially attributable to the interaction of its potential cytoprotective and anti-inflammatory mechanisms together with enhancement of the mucosal immunity through TLR-2/MyD88 signaling pathway.

Hypofractionated EGFR tyrosine kinase inhibitor limits tumor relapse through triggering innate and adaptive immunity.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are a first-line therapy for rapidly killing tumors such as those associated with non-small cell lung cancer by blocking oncogenic receptor signaling, but tumor relapse often occurs. Here, we have observed that hypofractionated EGFR TKI treatment (HypoTKI) is more potent than standard hyperfractionated EGFR TKI treatment (HyperTKI), and its antitumor effect associated with preventing tumor relapse depends on T cells. HypoTKI triggers greater innate sensing for type I IFN and CXCL10 production through the Myd88 signaling pathway to enhance tumor-specific T cell infiltration and reactivation. We also demonstrate that timely programmed cell death ligand-1 (PD-L1) blockade can synergize with HypoTKI to control advanced large tumors and effectively limit tumor relapse without severe side effects. Our study provides evidence for exploring the potential of a proper combination of EGFR TKIs and immunotherapy as a first-line treatment for treating EGFR-driven tumors.