Revisiting bupropion anti-inflammatory action: involvement of the TLR2/TLR4 and JAK2/STAT3

There are accumulating reports regarding poor response to common antidepressant therapy. Antidepressant resistance is often linked to inflammatory system activation and patients displaying inflammation prior to the treatment are less responsive to antidepressants. We hypothesized that the inefficacy of antidepressant therapy in some patients may be attributable to the drugs' inflammatory mode of action, which has been overlooked because of their substantial therapeutic benefit. Bupropion is a commonly prescribed antidepressant that is often used to treat seasonal affective disorders as well. Nevertheless, research suggests that bupropion causes inflammation and worsens depressive symptoms. Therefore, we investigated the impact of bupropion on cytokines of innate and adaptive immunity, as well as immune signaling pathways. We treated lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs) with different doses of bupropion. Pro-/anti-inflammatory cytokines [tumor necrosis factor alpha (TNFα), interleukin-1β (IL-1β), IL-17, and IL-10] were assessed at both transcriptional and translational levels as well as the involvement of JAK2 /STAT3, TLR2, and TLR4 signaling in this process. Bupropion reduced IL-17A, TNFα, and IL-1β protein levels in the cultures. Nonetheless, bupropion increased IL-1β (P < 0.0001), TNFα (P < 0.0001), and IL-17A (P < 0.05) mRNA levels. Treatment enhanced both IL-10 concentration (P < 0.0001) and gene expression (P < 0.0001). TLR2 (P < 0.0001), TLR4 (P < 0.0001), JAK2 (P < 0.0001), and STAT3 (P < 0.0001) gene expression also rose in response to bupropion. The findings imply that bupropion, particularly 50 μM and 100 μM, has pro-inflammatory effects and should be co-administered with anti-inflammatory medications, at least in patients with inflammatory conditions.

Knockdown of H19 Inhibits the Pathogenesis of Acne Vulgaris by Targeting the miR-196a/TLR2/NF-κB Axis

Acne vulgaris (AV) is a chronic inflammatory disease of the pilosebaceous unit, and Propionibacterium acnes (P. acnes) has been implicated in acne inflammation. Numerous studies have shown that non-coding RNAs play important roles in regulating the pathophysiological processes of acne. In addition, the first imprinted long non-coding RNA (lncRNA) identified, H19, plays a critical role in inflammatory disease. However, the expression and role of H19 in AV remain unclear. In this study, we investigated the effects of H19 in keratinocytes and explored the regulatory mechanisms underlying these effects. H19 was upregulated in keratinocytes treated with P. acnes in a concentration-dependent manner. The phosphorylated forms of the nuclear factor (NF)-κB-related proteins IκBα (p-IκBα) and p65 (p-P65) were significantly upregulated after P. acnes treatment. Additionally, secretion of the proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 was upregulated in a concentration-dependent manner. Knockdown of H19 inhibited the expression of p-IκBα and p-P65 as well as the secretion of TNF-α, IL-6, and IL-8 in keratinocytes treated with P. acnes. Moreover, H19 was found to exert its proinflammatory effects by activating NF-κB. H19, which was localized mainly in the cytoplasm of keratinocytes, facilitated Toll-like receptor 2 (TLR2) expression by acting as a miR-196a sponge. H19 thus promoted the activation of NF-κB and the secretion of inflammatory cytokines through the miR-196a/TLR2 axis. These findings provide novel insight into the pathogenesis of AV.

Differential profiles of soluble and cellular toll like receptor (TLR)-2 and 4 in chronic periodontitis

Chronic periodontitis is a common inflammatory disease initiated by a complex microbial biofilm and mediated by the host response causing destruction of the supporting tissues of the teeth. Host recognition of pathogens is mediated by toll-like receptors (TLRs) that bind conserved molecular patterns shared by large groups of microorganisms. The oral epithelial cells respond to most periodontopathic bacteria via TLR-2 and TLR-4. In addition to the membrane-associated receptors, soluble forms of TLR-2 (sTLR-2) and TLR-4 (sTLR-4) have been identified and are thought to play a regulatory role by binding microbial ligands. sTLR-2 has been shown to arise from ectodomain shedding of the extracellular domain of the membrane receptor and sTLR-4 is thought to be an alternate spliced form. Many studies have previously reported the presence of elevated numbers of viable exfoliated epithelial cells in the saliva of patients with chronic periodontitis. The objective of this study was to investigate the potential value of salivary sTLR-2 and sTLR-4 together with the paired epithelial cell-associated TLR-2/4 mRNA as diagnostic markers for chronic periodontitis. Unstimulated whole saliva was collected after obtaining informed consent from 40 individuals with either periodontitis or gingivitis. The sTLR-2 and sTLR4 in saliva was measured by enzyme-linked immunosorbent assay. The TLR-2 and TLR-4 transcript in the epithelial cells in saliva was measured by real time polymerase chain reaction. While levels of sTLR-2 exhibited an inverse correlation, sTLR-4 positively correlated with clinical parameters in the gingivitis cohort. Interestingly, both correlations were lost in the periodontitis cohort indicating a dysregulated host response. On the other hand, while the sTLR-2 and the paired epithelial cell associated TLR-2 mRNA exhibited a direct correlation (r2 = 0.62), that of sTLR4 and TLR-4 mRNA exhibited an inverse correlation (r2 = 0.53) in the periodontitis cohort. Collectively, assessments of salivary sTLR2 and sTLR4 together with the respective transcripts in the epithelial cells could provide clinically relevant markers of disease progression from gingivitis to periodontitis.

Quercetin Protects Mice from ConA-Induced Hepatitis by Inhibiting HMGB1-TLR Expression and Down-Regulating the Nuclear Factor Kappa B Pathway

The dietary flavonoid quercetin has hepatoprotective effects. We analyzed the effects of quercetin on concanavalin A (ConA)-induced hepatitis in mice and its underlying molecular mechanisms of action. Mice were administered quercetin (50 mg/kg body weight, i.p.) or vehicle 30 min before intravenous administration of ConA. Quercetin pretreatment significantly reduced the ConA-induced elevations in plasma aminotransferase concentrations and liver necrosis, as well as reducing serum concentrations of the pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interferon-γ, and interleukin-4. Quercetin pretreatment also reduced expression of high-mobility group box 1 protein (HMGB1) and toll-like receptor (TLR)-2 and TLR-4 messenger RNA (mRNA) and protein in liver tissues. Quercetin pretreatment significantly inhibited degradation of inhibitory kappa B alpha and modulated ConA-induced nuclear translocation in the liver of nuclear factor kappa B (NF-κB) p65. These results demonstrate that quercetin protects against ConA-mediated hepatitis in mice by attenuating the HMGB1-TLRs-NF-κB signaling pathway.

GM-CSF Down-Regulates TLR Expression via the Transcription Factor PU.1 in Human Monocytes

Toll-like receptors (TLR) are crucial sensors of microbial agents such as bacterial or viral compounds. These receptors constitute key players in the induction of inflammation, e.g. in septic or chronic inflammatory diseases. Colony-stimulating factors (CSFs) such as granulocyte-macrophage-CSF (GM-CSF) or granulocyte-CSF (G-CSF) have been extensively investigated in their capacity to promote myelopoiesis in febrile neutropenia or to overcome immunosuppression in patients suffering from sepsis-associated neutropenia or from monocytic immunoincompetence. We report here that GM-CSF, downregulates TLR1, TLR2 and TLR4 in a time- and dose-dependent fashion in human monocytes. Diminished pathogen recognition receptor expression was accompanied by reduced downstream p38 and extracellular-signal-regulated kinase (ERK) signaling upon lipoteichoic acid (LTA) and lipopolysaccharide (LPS) binding-and accordingly led to impaired proinflammatory cytokine production. Knockdown experiments of the transcription factors PU.1 and VentX showed that GM-CSF driven effects on TLR regulation is entirely PU.1 but not VentX dependent. We further analysed monocyte TLR and CD14 expression upon exposure to the IMID® immunomodulatory drug Pomalidomide (CC-4047), a Thalidomide analogue known to downregulate PU.1. Indeed, Pomalidomide in part reversed the GM-CSF-mediated effects. Our data indicate a critical role of PU.1 in the regulation of TLR1, 2, 4 and of CD14, thus targeting PU.1 ultimately results in TLR modulation. The PU.1 mediated immunomodulatory properties of GM-CSF should be taken into consideration upon usage of GM-CSF in inflammatory or infection-related conditions.

Roles of Toll-like receptors 2 and 6 in the inflammatory response to Mycoplasma gallisepticum infection in DF-1 cells and in chicken embryos

While Mycoplasma gallisepticum (MG) is a major pathogen that causes chronic respiratory diseases in chicken, the molecular mechanism of MG infection is not clear. In this study, we investigated the roles of Toll-like receptor 2 (TLR2) and 6 (TLR6) in MG infection. We found that TLR2 type 2 (TLR2-2) and TLR6 had differential expressions in chicken embryo fibroblasts (DF-1 cells), where TLR6 was highly expressed, but TLR2-2 was barely expressed. Upon MG infection, TLR6 expression was upregulated, followed by upregulation of downstream factors, MyD88, NF-κB, IL2, IL6, and TNF-α. Knockdown of TLR6 expression by shRNA abolished the MG-induced inflammatory responses. More interestingly, in the presence of TLR6, TLR2-2 didn't respond to MG infection in DF-1 cells. When TLR6 was knocked down by shRNA, however, TLR2 was upregulated upon MG infection, which was followed by upregulation of proinflammatory genes. Finally, we tested effects of the MG infection on expression of TLR2-2 and TLR6 in the lungs and trachea tissues of chicken embryos. We found both TLR2-2 and TLR6 were upregulated upon MG infection, followed by upregulation of the downstream NF-κB-mediated inflammatory responses. This study was the first to report the differential roles of TLR2-2 and TLR6 in MG-infected DF-1 cells and chicken embryos.

A phase trial of the oral Lactobacillus casei vaccine polarizes Th2 cell immunity against transmissible gastroenteritis coronavirus infection

Transmissible gastroenteritis coronavirus (TGEV) is a member of the genus Coronavirus, family Coronaviridae, order Nidovirales. TGEV is an enteropathogenic coronavirus that causes highly fatal acute diarrhoea in newborn pigs. An oral Lactobacillus casei (L. casei) vaccine against anti-transmissible gastroenteritis virus developed in our laboratory was used to study mucosal immune responses. In this L. casei vaccine, repetitive peptides expressed by L. casei (specifically the MDP and tuftsin fusion protein (MT)) were repeated 20 times and the D antigenic site of the TGEV spike (S) protein was repeated 6 times. Immunization with recombinant Lactobacillus is crucial for investigations of the effect of immunization, such as the first immunization time and dose. The first immunization is more important than the last immunization in the series. The recombinant Lactobacillus elicited specific systemic and mucosal immune responses. Recombinant L. casei had a strong potentiating effect on the cellular immunity induced by the oral L. casei vaccine. However, during TGEV infection, the systemic and local immune responses switched from Th1 to Th2-based immune responses. The systemic humoral immune response was stronger than the cellular immune response after TGEV infection. We found that the recombinant Lactobacillus stimulated IL-17 expression in both the systemic and mucosal immune responses against TGEV infection. Furthermore, the Lactobacillus vaccine stimulated an anti-TGEV infection Th17 pathway. The histopathological examination showed tremendous potential for recombinant Lactobacillus to enable rapid and effective treatment for TGEV with an intestinal tropism in piglets. The TGEV immune protection was primarily dependent on mucosal immunity.

Proteomic Profiling of Iron Overload-Induced Human Hepatic Cells Reveals Activation of TLR2-Mediated Inflammatory Response

Background: Hepatic iron overload is common in patients who have undergone hematopoietic cell transplantation (HCT) and may predispose to peri- and post-HCT toxicity. To better reveal more molecules that might be involved in iron overload-induced liver injury, we utilized proteomics to investigate differentially expressed proteins in iron overload-induced hepatocytes vs. untreated hepatocytes. Methods and Results: HH4 hepatocytes were exposed to ferric ammonium citrate (FAC) to establish an in vitro iron overload model. Differentially expressed proteins initiated by the iron overload were studied by two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS) analysis. We identified 93 proteins whose quantity statistically significantly changes under excess hepatocyte iron conditions. Gene Ontology (GO) analysis showed that these differentially expressed proteins in HH4 cells are involved in various biological process including endocytosis, response to wounding, di-, trivalent inorganic cation homeostasis, inflammatory response, positive regulation of cytokine production, and etc. Meanwhile, proteomics data revealed protein level of TLR2 and IL6ST significantly increased 7 times and 2.9 times, respectively, in iron overloaded HH4 cells. Our subsequent experiments detected that FAC-treated HH4 cells can activate IL6 expression through TLR2-mediated inflammatory responses via the NF-κB pathway. Conclusions: In this study, we demonstrated that iron overload induced hepatocytes triggering TLR2-mediated inflammatory response via NF-κB signaling pathway in HH4 cells.

Effects of the New Generation Synthetic Reconstituted Surfactant CHF5633 on Pro- and Anti-Inflammatory Cytokine Expression in Native and LPS-Stimulated Adult CD14+ Monocytes

Background

Surfactant replacement therapy is the standard of care for the prevention and treatment of neonatal respiratory distress syndrome. New generation synthetic surfactants represent a promising alternative to animal-derived surfactants. CHF5633, a new generation reconstituted synthetic surfactant containing SP-B and SP-C analogs and two synthetic phospholipids has demonstrated biophysical effectiveness in vitro and in vivo. While several surfactant preparations have previously been ascribed immunomodulatory capacities, in vitro data on immunomodulation by CHF5633 are limited, so far. Our study aimed to investigate pro- and anti-inflammatory effects of CHF5633 on native and LPS-stimulated human adult monocytes.

Methods

Highly purified adult CD14⁺ cells, either native or simultaneously stimulated with LPS, were exposed to CHF5633, its components, or poractant alfa (Curosurf^®). Subsequent expression of TNF-α, IL-1β, IL-8 and IL-10 mRNA was quantified by real-time quantitative PCR, corresponding intracellular cytokine synthesis was analyzed by flow cytometry. Potential effects on TLR2 and TLR4 mRNA and protein expression were monitored by qPCR and flow cytometry.

Results

Neither CHF5633 nor any of its components induced inflammation or apoptosis in native adult CD14⁺ monocytes. Moreover, LPS-induced pro-inflammatory responses were not aggravated by simultaneous exposure of monocytes to CHF5633 or its components. In LPS-stimulated monocytes, exposure to CHF5633 led to a significant decrease in TNF-α mRNA (0.57 ± 0.23-fold, p = 0.043 at 4h; 0.56 ± 0.27-fold, p = 0.042 at 14h). Reduction of LPS-induced IL-1β mRNA expression was not significant (0.73 ± 0.16, p = 0.17 at 4h). LPS-induced IL-8 and IL-10 mRNA and protein expression were unaffected by CHF5633. For all cytokines, the observed CHF5633 effects paralleled a Curosurf®-induced modulation of cytokine response. TLR2 and TLR4 mRNA and protein expression were not affected by CHF5633 and Curosurf®, neither in native nor in LPS-stimulated adult monocytes.

Conclusion

The new generation reconstituted synthetic surfactant CHF5633 was tested for potential immunomodulation on native and LPS-activated adult human monocytes. Our data confirm that CHF5633 does not exert unintended pro-inflammatory effects in both settings. On the contrary, CHF5633 significantly suppressed TNF-α mRNA expression in LPS-stimulated adult monocytes, indicating potential anti-inflammatory effects.

Surface Expression and Genetic Variants of Toll-like Receptor 2 in Pulmonary Tuberculosis Patients

Innate immunity plays an important role in the host defense against Mycobacterium tuberculosis (M. tuberculosis). Toll-like receptor-2 (TLR2) is the main receptor and one of central components in initiation of innate immunity against M. tuberculosis. The study aimed to evaluate TLR2 surface expression on peripheral blood monocytes and study its association with variants in TLR2 597T/C single nucleotide polymorphisms (SNPs) in patients with pulmonary tuberculosis. Fifty pulmonary tuberculosis patients and 50 healthy controls were investigated for TLR2 expression on CD14+ monocytes by flow cytometry and TLR2 597T/C genotyping by Tetra primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). A significant increase (P < 0.001) in TLR 2 expression was detected in tuberculosis patients compared to controls. TLR2 597 TC and CC genotypes were higher in pulmonary tuberculosis patients (OR =2.79, 95% CI =1.02-7.95 and OR =4.26, 95% CI =0.40-214.00) respectively. Genotype TT was associated with reduced risk of being a case of pulmonary tuberculosis. There was no association of TLR2 surface expression on monocytes in pulmonary tuberculosis patients with different TLR2 597T/C genotypes. It is concluded that elevated expression of TLR2 on CD14+ monocytes in pulmonary tuberculosis patients confirms the role of TLR2 in host defense against M. tuberculosis. 597T/C polymorphism of TLR 2 gene may be a risk factor for susceptibility to pulmonary tuberculosis in a sample Egyptian population.

Tlr4 Deficiency Protects against Cardiac Pressure Overload Induced Hyperinflammation

Transverse aortic constriction provokes a pro-inflammatory reaction and results in cardiac hypertrophy. Endogenous ligands contribute to cardiac hypertrophy via toll-like receptor (TLR)-4 binding. A lack of TLR4 signaling diminishes hypertrophy and inflammation. Wild type mice undergoing aortic constriction respond to a lipopolysaccharide second-hit stimulus with hyperinflammation. The objective of this study was to assess whether other second-hit challenges utilizing TLR ligands provoke a comparable inflammatory reaction, and to find out whether this response is absent in TLR4 deficient mice. Assuming that cardiac stress alters the expression of pattern recognition receptors we analyzed the effects of transverse aortic constriction and second-hit virulence factor treatment on TLR expression, as well as cytokine regulation. Wild type and Tlr4-/- mice were subjected to three days of TAC and subsequently confronted with gram-positive TLR2 ligand lipoteichoic acid (LTA, 15 mg/g bodyweight) or synthetic CpG-oligodesoxynucleotide 1668 thioate (20 nmol/kg bodyweight, 30 min after D-galactosamin desensitization) signaling via TLR9. Hemodynamic measurements and organ preservation were performed 6 h after stimulation. Indeed, the study revealed a robust enhancement of LTA induced pattern recognition receptor and cytokine mRNA expression and a LTA-dependent reduction of hemodynamic pressure in TAC wild type mice. Second-Hit treatment with CpG-ODNs led to similar results. However, second-hit effects were abolished in Tlr4-/- mice. In total, these data indicate for the first time that cardiac stress increases the inflammatory response towards both, gram-negative and gram-positive, TLR ligands as well as bacterial DNA. The decrease of the inflammatory response upon TLR2 and -9 ligand challenge in TAC Tlr4-/- mice demonstrates that a lack of TLR4 signaling does not only prevent left ventricular hypertrophy but also protects the mice from a cardiac stress induced hyperinflammatory reaction.

Cerebral hypoxia-ischemia increases toll-like receptor 2 and 4 expression in the hippocampus of neonatal rats

AIM OF THE STUDY

Recent reports provide evidence that Toll-like receptors (TLRs) play a crucial role in cerebral ischemic injuries and neuronal cell death. The precise role of TLRs in mediating neuronal damage remains to be fully elucidated. In this study, we investigated the expression of TLR2 and TLR4 in the hippocampus of the neonatal rats.

MATERIALS AND METHODS

Postnatal day 7 Sprague-Dawley rats were used. The hypoxia-ischemia brain injury models were made by ligature of the left common carotid artery and then inhalation of 8%O(2)/92%N(2) for 2 h. TLR2 and TLR4 expression was assessed with immunohistochemical staining and Western blot assays at 3d, 7d, and 14d after injury.

RESULTS

At the 3d and 7d time points, we found a significant increase in the number of TLR2 and TLR4 positive cells in the hippocampus of the HI group when compared with the sham group (P<0.01). Western blot showed similar results.

CONCLUSIONS

The study indicates that TLR2 and TLR4 are involved in the hypoxic-ischemic injury of full-term neonatal brains.

mRNA TLR2 AND TLR4 EXPRESSION IN THE ENDOMETRIUM TISSUE IN WOMEN WITH ENDOMETRIOSIS ASSOSIATED WITH INFERTILITY

Endometriosis is an important medical and social problem as it causes stable pelvic pains, afflicts women of the reproductive age, provokes infertility characterized by poor outcome of treatment. In recent times much attention is paid to the mechanisms of congenital immunity as possible mediators of the development of endometriosis and targets of therapy. The work deals with the investigation of the levels of mRNA TLR2 and TLR4 expression in the tissue of eutopic endometrium in women with endometriosis and infertility in comparison with women afflicted with infertility of a tubular character with the aim to define the role of TLR2 and TLR4 in the development of infertility in case of endometriosis. The study was conducted by means of polymerase chain reaction (PCR) real-time method. The results of the study are indicative of an increased TLR2 and TLR4 expression (especially TLR2) in the endometrium in women with endometriosis. The results obtained may be indicative of an important role of TLR2 and TLR4 in the development of endometrioid ectopia and should be considered while treating infertility in women with endometriosis.

Targeting Toll-like receptor 2 inhibits growth of head and neck squamous cell carcinoma

Infection-driven inflammation has been proposed to be involved in the tumorigenesis of head and neck squamous cell carcinoma (HNSCC). Oral HNSCC is often colonized with microbes such as gram-positive bacteria and yeast, where ligands derived from their wall components have been shown to specifically bind to Toll-like receptor 2 (TLR2). Although TLR2 has been described to be expressed in oral HNSCC, its function has not been well characterized. Here, we show the expression of TLR2 in both HNSCC cell lines and primary patient-derived HNSCC xenograft tumors. Activation of TLR2 with a yeast-derived ligand of TLR2, zymosan, promoted organoid formation in an ex vivo model of tumor growth, while blockade with anti-TLR2 antibodies inhibited organoid formation. Zymosan also induced phosphorylation of ERK and the p65 subunit of NF-κB, which was inhibited in the presence of anti-TLR2 antibodies, indicating that this receptor is functional in HNSCC and that the signaling through these pathways is intact. TLR2 blockade also inhibited growth of human xenografted tumors in immunodeficient mice. In summary, our data show that TLR2 is a functional receptor expressed in human HNSCC that plays a direct pro-tumorigenic role, and that it can be therapeutically targeted with blocking antibodies to reduce tumor growth.

Down-regulation of TLR2, 3, 9 and Signaling Mediators, MyD88 and TRIF, Gene Transcript Levels in Patients with Kawasaki Disease Treated with IVIG

Kawasaki disease (KD) is an acute febrile systemic vasculitis of childhood characterized by elevated levels of inflammatory mediators at the acute stage. High-dose intravenous immunoglobulin (IVIG) is well accepted as a conventional therapy for KD. The aim of the present study was to determine the expression level of Toll like receptors (TLRs) and their corresponding signaling mediators in PBMCs of IVIG-treated KD patients. TLR2, 3, 9 and signaling mediators, MyD88 and TRIF transcript levels were determined in PBMCs from 31 KD patients, before (acute phase), 2 weeks later (sub-acute phase) and 6 weeks later (convalescent phase) of IVIG therapy using real time PCR. The mean age of the patients was 3.6 years and 65% of subjects were male and 35% were female. 20 age-matched irrelevant febrile patients and 20 healthy subjects were included as control groups. Elevated levels of TLR2, MyD88, and TRIF gene transcripts were observed in the PBMCs at acute phase of untreated KD patients in compression with normal subjects. IVIG therapy resulted in significant decrease in TLR2, 3 and 9 (60-90%) as well as MyD88 and TRIF (60-70%) transcripts following 2 and 6 weeks. With Regard to significant up-regulation of MyD88 and TRIF at the acute phase of KD, our findings suggest TLR signaling pathway potential in KD pathogenesis and may also support the assumption of an infectious background in KD. Down-regulation of TLR members and corresponding mediators in IVIG treated patient suggest general TLR pathway suppression as a novel anti-inflammatory mechanism of IVIG.

The expression of Toll-like receptors 2, 4, 5, 7 and 9 in Merkel cell carcinoma

AIM

We sought to clarify whether the expression of toll-like receptors (TLR) in Merkel cell carcinoma (MCC) is linked to tumor and patient characteristics, especially the presence of Merkel cell polyoma virus (MCV).

MATERIALS AND METHODS

The study comprised of 128 patients with data on Merkel cell polyomavirus (MCV) status and clinical features were included in the study. Immunohistochemistry for TLR expression was performed on tissue microarray (TMA) slides.

RESULTS

TLR 2, 4, 5, 7 and 9 expression was noted in most of the tumor specimens. Decreased expression of TLR 9 correlated strongly with MCV positivity. Cytoplasmic TLR 2 expression correlated with small tumor size, while nuclear TLR 2 and TLR 5 expressions with larger tumors. Increased nuclear TLR 4 expression and decreased TLR 7 expression were associated with older age.

CONCLUSION

TLR 2, 4, 5, 7 and 9 appear to reflect certain clinicopathological variables and prognostic markers of MCC tumors.

Expression and function of Toll-like receptors in peripheral blood mononuclear cells from patients with ovarian cancer

Inflammation has been implicated in the initiation and progression of ovarian cancer (OC), the underlying mechanisms of which are still unclear. We hypothesized that the abnormal expression of Toll-like receptors (TLRs), which were potential activators of nuclear factor-kappa B p65 (NF-κB p65), could promote inflammation and tumorigenesis in OC. In this study, we characterized the expression of TLRs in peripheral blood mononuclear cells (PBMCs) and found TLR2 and TLR6 mRNAs levels to be higher in PBMCs from OC patients than in those from benign disease (BC) or healthy normal controls (NC). Flow cytometry analysis showed that TLR1, TLR2 and TLR6 were highly expressed in monocytes from OC patients, but not in those from control subjects. Consistently, inflammatory cytokines interleukin (IL)-1β and IL-6 were up-regulated in PBMCs from OC patients upon stimulation with Pam3CSK4 (TLR1 ligand) and HKLM (TLR2 ligand), compared with unstimulated PBMCs. Stimulation of PBMCs with TLR ligands led to activation of downstream signaling molecules in TLRs (MyD88, TRAF6, TANK, NF-κB p65 and p-NF-κB p65). We also discovered that SK-OV-3-secreted factors were potent PBMCs activators, leading to the production of IL-1β, IL-6 and IL-8 through activation of TLRs and downstream signaling molecules in PBMCs. Before coculturing with SK-OV-3, pretreatment of THP-1 cells or PBMCs with monoclonal antibodies against TLR1, TLR2 or TLR6 inhibited the production of IL-1β and IL-6 and activation of MyD88, TRAF6, TANK, NF-κB p65 and p-NF-κB p65. Our results provided new evidence that TLR1, TLR2 and TLR6 signaling was linked with inflammation in OC microenvironment.

Inhibitory effects of teuclatriol, a sesquiterpene from salvia mirzayanii, on nuclear factor-κB activation and expression of inflammatory mediators

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia mirzayanii Rech. f. & Esfand. is an endemic plant, which is only distributed in the south of Iran. In traditional Iranian medicine, the aerial parts of Salvia mirzayanii have been used for infections, inflammatory diseases, and as a tonic. From this plant, the sesquiterpene teuclatriol was isolated by bioactivity-guided fractionation due to its anti-proliferative actions on human lymphocytes. The guaiane sesquiterpene is lacking the methylene-γ-lactone function that is typically involved in the inhibiting properties of sesquiterpenes on NF-κB, a pivotal transcription factor in inflammatory processes. We here investigated anti-inflammatory effects of teuclatriol on human macrophage-like and endothelial cells.

MATERIALS AND METHODS

Non-toxic doses of teuclatriol were determined for both cell types by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)-assay. The effect of teuclatriol on the activity of NF-κB in LPS-stimulated human monocytic THP-1 cells was studied using infrared electrophoretic mobility shift assay (IR-EMSA) using curcumin as positive control (32µM). THP-1 were differentiated into macrophage-like cells and evaluated for TNF-α secretion by L929 bioassay following stimulation with LPS and treatment with teuclatriol. Inflammatory gene expression in human umbilical vein endothelial cells (HUVEC), modeling target cells for TNF-α-induced inflammatory gene activation, was investigated by real-time RT-PCR.

RESULTS

The LPS-induced DNA binding activity of NF-κB in THP-1 was significantly decreased by non-toxic doses of teuclatriol (312 and 390µM). Teuclatriol reduced the production of TNF-α in a dose-dependent manner. mRNA levels of both monocyte chemoattractant protein (MCP)-1 and toll-like receptor (TLR)2 were decreased in TNF-α-activated HUVEC.

CONCLUSION

These data show an inhibitory effect of teuclatriol on NF-κB signaling at doses of 312µM and higher, validating the traditional use of Salvia mirzayanii in the treatment of inflammatory diseases. Future work on the mode of action of teuclatriol may provide new lead structures with NF-κB inhibiting properties, lacking possible side effects mediated via alkylating centers of sesquiterpene lactones.

Metalloproteinase-dependent TLR2 ectodomain shedding is involved in soluble toll-like receptor 2 (sTLR2) production

Toll-like receptor (TLR) 2, a type I membrane receptor that plays a key role in innate immunity, recognizes conserved molecules in pathogens, and triggering an inflammatory response. It has been associated with inflammatory and autoimmune diseases. Soluble TLR2 (sTLR2) variants have been identified in human body fluids, and the TLR2 ectodomain can negatively regulate TLR2 activation by behaving as a decoy receptor. sTLR2 generation does not involve alternative splicing mechanisms, indicating that this process might involve a post-translational modification of the full-length receptor; however, the specific mechanism has not been studied. Using CD14⁺ peripheral human monocytes and the THP-1 monocytic leukemia-derived cell line, we confirm that sTLR2 generation increases upon treatment with pro-inflammatory agents and requires a post-translational mechanism. We also find that the constitutive and ligand-induced release of sTLR2 is sensitive to pharmacological metalloproteinase activator and inhibitors leading us to conclude that metalloproteinase TLR2 shedding contributes to soluble receptor production. By expressing human TLR2 in ADAM10- or ADAM17-deficient MEF cells, we find both enzymes to be implicated in TLR2 ectodomain shedding. Moreover, using a deletion mutant of the TLR2 juxtamembrane region, we demonstrate that this domain is required for sTLR2 generation. Functional analysis suggests that sTLR2 generated by metalloproteinase activation inhibitsTLR2-induced cytokine production by this monocytic leukemia-derived cell line. The identification of the mechanisms involved in regulating the availability of soluble TLR2 ectodomain and cell surface receptors may contribute further research on TLR2-mediated processes in innate immunity and inflammatory disorders.

Expression and implication of toll-like receptors TLR2, TLR4 and TLR9 in colonic mucosa of patients with ulcerative colitis

Toll-like receptors (TLRs) family may play important roles in inflammatory bowel disease. This study examined the expression of TLR2, TLR4 and TLR9 in the colonic tissues of patients with ulcerative colitis (UC) and explored their roles in the pathogenesis of UC. Colonic biopsies were taken from the colon of 30 patients with mild or moderate UC (at active phase) and 10 healthy controls during colonoscopy. TLR2, TLR4 and TLR9 protein expression levels were immunohistochemically detected. The mRNA expression levels of TLR2, TLR4 and TLR9 were assessed by reverse transcription polymerase chain reaction (RT-PCR). The disease activity index (DAI), colonoscopic and histologic grades and fecal microbial flora were determined. Histological examination showed that the intestinal mucous membrane of UC patients underwent acute inflammation changes. Immunohistochemistry exhibited that the expression levels of TLR2, TLR4 and TLR9 in colon epithelia and inflammatory cells were higher in UC patients than in control group (P<0.01). The mRNA expression levels of TLR2, TLR4 and TLR9 were increased in UC patients but were not detected in the normal controls. Expression levels of TLR2, TLR4 and TLR9 were positively correlated, and bore close correlation with DAI, colonoscopic and histologic grades and fecal microbial flora. An important mechanism of UC might be that abnormal activation of mucosal immunity by intestinal dysbacteriosis caused dysregulation of TLRS that mediates innate immunity.

Expression pattern of Toll-like receptors (TLRs) in different organs and effects of lipopolysaccharide on the expression of TLR 2 and 4 in reproductive organs of female rabbit

Toll-like receptors (TLRs) are vital for innate immunity, and they were expressed in various immune cells, tissues and organs. Moreover, TLRs specific expression pattern in different cells, tissue and organs have been confirmed to have correlation with the ability to resistance to pathogenic challenges. The present study aimed to determine the expression profiles and levels of TLR2, 3, 4, 5, 6, 8 and 10 in the lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus of female rabbits, and whether the expression level of TLR2 and 4 in the ovary, oviduct, uterine horn and body, and cervix were affected by lipopolyasaccharide (LPS). The tissues of the lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus were collected from four rabbits which didn't be treated as 0 h. 16 rabbits in LPS group were injected with LPS (according to 0.5mg/kg body weight) and 16 rabbits in control group were injected with saline (LPS carrier), hereafter the tissues of the uterine horn and body, cervix, ovary and oviduct from 32 rabbits were collected after 1.5, 3, 6, and 12h (n=4 each group) postinjection. The expression profiles of TLRs were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR), and expression level of TLRs were examined using quantitative real-time PCR (qRT-PCR). The results shown: TLR2, 3, 4, 5, 6, 8 and 10 were expressed in lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus of female rabbits, but their expression level had great difference in the same organs, and each TLR has different expression level in the different organs. After LPS-stimulation, the expression of TLR2 in the uterine body and horn was significantly higher than that in control group by 3h and 12h of postinjection (P<0.05) respectively. The expression of TLR4 in ovary and uterine body was significantly higher than that in control group by 3 and 12h of postinjection (P<0.05), and the expression of TLR4 in uterine body was greater than that in control by 3h postinjection (P<0.05). The results suggested LPS upregulated the expression of TLR2 and 4 in uterine body and horn, and the expression of TLR4 in ovary.

The oxidative stress product carboxyethylpyrrole potentiates TLR2/TLR1 inflammatory signaling in macrophages

Oxidative stress is key in the pathogenesis of several diseases including age-related macular degeneration (AMD), atherosclerosis, diabetes, and Alzheimer's disease. It has previously been established that a lipid peroxidation product, carboxyethylpyrrole (CEP), accumulates in the retinas of AMD patients. Retinal infiltrating macrophages also accumulate in the retinas of both AMD patients and in a murine model of AMD. We therefore investigated the ability of CEP-adducts to activate innate immune signaling in murine bone-marrow derived macrophages (BMDMs). We found that CEP specifically synergizes with low-dose TLR2-agonists (but not agonists for other TLRs) to induce production of inflammatory cytokines. Moreover, CEP selectively augments TLR2/TLR1-signaling instead of TLR2/TLR6-signaling. These studies uncover a novel synergistic inflammatory relationship between an endogenously produced oxidation molecule and a pathogen-derived product, which may have implications in the AMD disease process and other oxidative stress-driven pathologies.

Chlamydophila pneumonia and increased TLR4 gene expression in leukocytes are associated with acute myocardial infarction

We investigated the relationship of the positivity for Chlamydophila pneumoniae (Cpn) and Mycoplasma pneumonia (Mpn), inflammatory and metabolic markers, and mRNA expression and polymorphisms of the TLR2, TLR4, IL-6 and TNFA genes with acute myocardial infarction (AMI). Two hundred and eighteen individuals (98 AMI and 120 non-AMI) were selected at two Clinical Centers. Blood samples were drawn to extract DNA and RNA and to measure laboratory variables including anti-Cpn IgM and IgG. Cpn and Mpn genomic DNA as well as TLR2, TLR4, IL-6 and TNFA mRNA expression were evaluated by quantitative real-time PCR (qPCR). Gene polymorphisms were detected by PCR-HRM. AMI patients had higher positivity for Cpn-DNA (17.3%) than non-AMI group (6.7%, p=0.018). In addition, Cpn-DNA positivity was an independent predictor of risk for AMI (OR: 2.56, CI: 1.08 - 6.04, p=0.031). Positivity for anti-Cpn IgG and Mpn-DNA was similar between AMI and non-AMI (> 0.05). TLR4 mRNA expression was higher in AMI than non-AMI individuals (p=0.005). CD14 -260C> T, TNFA -308A> G, TLR2 c.2258G> A, TLR4 c.896A> G and TLR4 c.1196> T variants were not associated with increased risk for AMI (p> 0.05). In the AMI group, individuals carrying CD14 -260CC genotype had higher hsCRP levels than CT/TT carriers (p=0.041). These results are suggestive that Cpn-DNA positivity and increased TLR4 mRNA expression in blood leukocytes may be associated with AMI and could be useful markers to evaluate the severity and progression of the atherosclerotic disease in AMI patients.

TLR2 engagement on CD4(+) T cells enhances effector functions and protective responses to Mycobacterium tuberculosis

We have previously demonstrated that mycobacterial lipoproteins engage TLR2 on human CD4(+) T cells and upregulate TCR-triggered IFN-γ secretion and cell proliferation in vitro. Here we examined the role of CD4(+) T-cell-expressed TLR2 in Mycobacterium tuberculosis (MTB) Ag-specific T-cell priming and in protection against MTB infection in vivo. Like their human counterparts, mouse CD4(+) T cells express TLR2 and respond to TLR2 costimulation in vitro. This Th1-like response was observed in the context of both polyclonal and Ag-specific TCR stimulation. To evaluate the role of T-cell TLR2 in priming of CD4(+) T cells in vivo, naive MTB Ag85B-specific TCR transgenic CD4(+) T cells (P25 TCR-Tg) were adoptively transferred into Tlr2(-/-) recipient C57BL/6 mice that were then immunized with Ag85B and with or without TLR2 ligand Pam3 Cys-SKKKK. TLR2 engagement during priming resulted in increased numbers of IFN-γ-secreting P25 TCR-Tg T cells 1 week after immunization. P25 TCR-Tg T cells stimulated in vitro via TCR and TLR2 conferred more protection than T cells stimulated via TCR alone when adoptively transferred before MTB infection. Our findings indicate that TLR2 engagement on CD4(+) T cells increases MTB Ag-specific responses and may contribute to protection against MTB infection.

CMV infection, TLR-2 and -4 expression, and cytokine profiles in early-onset preeclampsia with HELLP syndrome

PROBLEM

Cytomegalovirus (CMV) infection was previously reported in pregnancy complications. However, its seroprevalence and associated Toll-like receptor (TLR) expression in early-onset preeclampsia (EOPE) with hemolysis, elevated liver enzyme and low platelets syndrome (HELLPs) are unexplored.

METHOD OF STUDY

A case–control study was performed to examine maternal CMV antibodies, neutrophil Toll-like receptor (TLR)-2 and -4 expression as well as the cytokine profile in EOPE with HELLPs (EOPE-HELLPs) (n = 10), late-onset preeclampsia (LOPE) (n = 20), normal pregnancy (n = 60), and non-pregnancy (n = 20) controls.

RESULTS

EOPE-HELLPs had significantly increased CMV IgG sero-positivity, upregulated TLR-2/-4 mRNA expression, increased serum IL-6 and TNF-α, and reduced IL-10 compared with matched normal and non-pregnancy controls. No significant difference was observed between LOPE and normal pregnancy controls.

CONCLUSION

We observed a significant association between CMV IgG sero-positivity and innate immune response in EOPE-HELLPs. Our data suggest that CMV infection may be a risk factor for this disorder.

Ex vivo cytokine release and pattern recognition receptor expression of subjects exposed to dampness: pilot study to assess the outcome of mould exposure to the innate immune system

In rooms with moisture damage, the indoor air can be enriched with microorganisms causing a variety of symptoms. Due to the highly diverse composition of bioaerosols and the multiple effects on humans, an assessment of the health risk is not sufficiently possible. The aim of this study was to characterize the features of innate immunity using blood from subjects exposed to moisture damage compared to control subjects living in houses without visible moisture damage. We investigated the expression of TLR-2, TLR-4 and dectin-1 on the surface of monocytes from both fresh blood and after in vitro stimulation with the model substances E. coli endotoxin, zymosan A, Pam3Cys and Aspergillus versicolor in 25 exposed subjects and 25 control subjects. In vitro stimulation of whole blood with the same components was performed for 20 h and the release of inflammatory mediators IL-8 and IL-1β were quantified. In addition to an enhanced number of blood leucocytes, the expression of the receptors TLR-2, TLR-4 and dectin-1 on blood monocytes was significantly enhanced in exposed subjects. In contrast, no different alteration in expression was detected between exposed and control group after in vitro stimulation with the model substances. The release of IL-8 and IL-1β after stimulation of whole blood with A. versicolor was increased in subjects exposed to moisture damage. Furthermore, in the exposed subjects the IL-1β release was significantly enhanced after in vitro stimulation with E. coli endotoxin (1000 pg/mL). In conclusion, features of the innate immune system (receptor expression and mediator release of monocytes) are altered in subjects exposed to moisture damage which may be a potential explanation for the increased incidence of respiratory health diseases observed in these populations.

Study of expression of TLR2, TLR4 and transckription factor NF-kB structures of galt of rats in the conditions of the chronic social stress and modulation of structure of intestinal microflora

The present study was conducted to investigate of the influence of chronic social stress (CSS) and modulation of the composition of intestinal microflora on the distribution of TLR2+-, TLR4+- and Nf-kB+-cells in the GALT of ileum of the rats. Researchers have been conducted on 84 rats (female) of Wistar line, which were divided on 7 experimental groups: control rats (group 1); rats, which were modeled CSS1 by means of three weeks social isolation and prolong psychoemotional influence (group2); rats, which having CSS 2 modeling by means of keeping animals in over populated cages with every day change of grouping (group 3); rats with CSS1 and CSS2, which were made the modeling of intestinal microflora by means of administrations of aminoglycosed antibiotic kanamycin (group 4 and 5, accordingly); rats with CSS1 and CSS2, which were made the modeling of intestinal microflora by means of everyday administrations of lactobacterine (groups 6 and 7, accordingly). Structure of population of TLR2+-, TLR4+- and Nf-kB+-cells has been studied by the analysis of serial histological sections using the method of direct and indirect immunofluorescense with monoclonal antibodies to TLR2, TLR4 and Nf-kB. CSS development is accompanied with increase in total lymphocytes expressing TLR2 and 4 type GALT rats with the most pronounced in LFV (TLR2+-lymphocytes) and PP LFs (TLR4+-cells) led to an increase in the number of Nf-kB+- cells: in LFV a 1.8-2 fold (p<0.05) in PP at the sub - 52-91% (p<0.05) in PP LFs - for 89-92% (p<0.05), and it is also influenced on the density of TLR2, TLR4, and the concentration of Nf-kB in immunopositive cells. AB and PB injections were accompanied by a decrease in the number of studied cells, so in the separate zone GALT is increased to their number, changing the density of immune system receptors.

[Microbiocenosis of the human nasal mucous membrane in the conditions of industrial city]

In this work we studied the effect of industrial pollution on the mechanisms involved in the adaptation of the nasal microbiocenosis of healthy residents of the industrial city to external influences. In the given biotop composition of the microbiota and its biological properties, as well as the specific indicators of rhinocytogram and expression of TLR-2 and TLR-4 cells of the mucous membranes have been studied. Accommodation in relatively polluted industrial areas of the city induces an increase in the population of coagulase positive staphylococci and improve their adhesion activity, as well as strengthens destructive processes in the epithelium. Analysis of resistance phenotypes of staphylococcus showed that around 30 % of the strains of coagulase negative staphylococci and about 20 % of the strains of coagulase positive staphylococci have phenotype mecA. Among coagulase negative staphylococci higher number of strains with multiple resistance to β- lactams, aminoglycosides, and antibiotics of MLS group have been revealed. To such changes in the components of microbiocenosis the cells of the mucous membrane of the nose react by increasing the numbers of TLR-2+ epithelial cells, increased expression of TLR-2 by epithelial cells and reduced expression of TLR-4 by neutrophils.

Immunolocalization of toll-like receptor 2 in viral warts and molluscum contagiosum

OBJECTIVE

To explore toll-like receptor 2 (TLR2) immunolocalization and its possible role in the innate immune response against viral warts and molluscum contagiosum (MC).

STUDY DESIGN

Using standard immunohistochemical techniques, we examined 50 cases (25 cases with viral warts and 25 cases with MC) together with normal skin biopsies of 25 age and sex-matched subjects who comprised the control group.

RESULTS

TLR2 was expressed in the epidermis of all controls and in 94% of study cases. Staining patterns were cytoplasmic, membranous, nuclear and combined. There was a significant difference between cases and controls regarding the intensity (p = 0.0001) and pattern (p = 0.001) of TLR2 expression, where intense expression was in favor of cases and membranous and nuclear pattern of staining was seen only in cases. The intensity of TLR2 expression was significantly associated with patients of young age (p = 0.04), short disease duration (p = 0.04), facial location (p = 0.009), and MC category (p = 0.02).

CONCLUSION

Our study suggests that upregulation of TLR2 is involved in the induction of defense mechanism against human papillomavirus and MC virus. Its nuclear localization may be related to virus pathogenesis, virus-TLR interaction, or to other unknown molecular events.

Dental infection of Porphyromonas gingivalis exacerbates high fat diet-induced steatohepatitis in mice

BACKGROUND

We investigated the effects of dental infection with Porphyromonas gingivalis (P.g.), an important periodontal pathogen, on NASH progression, by feeding mice a high fat diet (HFD)and examining P.g. infection in the liver of NASH patients.

METHODS

C57BL/6J mice were fed either chow-diet (CD) or HFD for 12 weeks, and then half of the mice in each group were infected with P.g. from the pulp chamber (HFD-P.g.(-), HFD-P.g.(+), CD-P.g.(-) and CD-P.g.(+)). Histological and immunohistochemical examinations, measurement of serum lipopolysaccharide (LPS) levels and ELISA for cytokines in the liver were performed. We then studied the effects of LPS from P.g. (P.g.-LPS) on palmitate-induced steatotic hepatocytes in vitro, and performed immunohistochemical detection of P.g. in liver biopsy specimens of NASH patients.

RESULTS

Serum levels of LPS are upregulated in P.g.(+) groups. Steatosis of the liver developed in HFD groups, and foci of Mac2-positive macrophages were prominent in HFD-P.g.(+). P.g. was detected in Kupffer cells and hepatocytes. Interestingly, areas of fibrosis with proliferation of hepatic stellate cells and collagen formation were only observed in HFD-P.g.(+). In steatotic hepatocytes, expression of TLR2, one of the P.g.-LPS receptors, was upregulated. P.g.-LPS further increased mRNA levels of palmitate-induced inflammasome and proinflammatory cytokines in steatotic hepatocytes. We demonstrated for the first time that P.g. existed in the liver of NASH patients with advanced fibrosis.

CONCLUSIONS

Dental infection of P.g. may play an important role in NASH progression through upregulation of the P.g.-LPS-TLR2 pathway and activation of inflammasomes. Therefore, preventing and/or eliminating P.g. infection by dental therapy may have a beneficial impact on management of NASH.

Receptor for advanced glycation end products regulates adipocyte hypertrophy and insulin sensitivity in mice: involvement of Toll-like receptor 2

Receptor for advanced glycation end products (RAGE) has been shown to be involved in adiposity as well as atherosclerosis even in nondiabetic conditions. In this study, we examined mechanisms underlying how RAGE regulates adiposity and insulin sensitivity. RAGE overexpression in 3T3-L1 preadipocytes using adenoviral gene transfer accelerated adipocyte hypertrophy, whereas inhibitions of RAGE by small interfering RNA significantly decrease adipocyte hypertrophy. Furthermore, double knockdown of high mobility group box-1 and S100b, both of which are RAGE ligands endogenously expressed in 3T3-L1 cells, also canceled RAGE-medicated adipocyte hypertrophy, implicating a fundamental role of ligands-RAGE ligation. Adipocyte hypertrophy induced by RAGE overexpression is associated with suppression of glucose transporter type 4 and adiponectin mRNA expression, attenuated insulin-stimulated glucose uptake, and insulin-stimulated signaling. Toll-like receptor (Tlr)2 mRNA, but not Tlr4 mRNA, is rapidly upregulated by RAGE overexpression, and inhibition of Tlr2 almost completely abrogates RAGE-mediated adipocyte hypertrophy. Finally, RAGE(-/-) mice exhibited significantly less body weight, epididymal fat weight, epididymal adipocyte size, higher serum adiponectin levels, and higher insulin sensitivity than wild-type mice. RAGE deficiency is associated with early suppression of Tlr2 mRNA expression in adipose tissues. Thus, RAGE appears to be involved in mouse adipocyte hypertrophy and insulin sensitivity, whereas Tlr2 regulation may partly play a role.

Augmented TLR2 expression on monocytes in both human Kawasaki disease and a mouse model of coronary arteritis

BACKGROUND

Kawasaki disease (KD) of unknown immunopathogenesis is an acute febrile systemic vasculitis and the leading cause of acquired heart diseases in childhood. To search for a better strategy for the prevention and treatment of KD, this study compared and validated human KD immunopathogenesis in a mouse model of Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis.

METHODS

Recruited subjects fulfilled the criteria of KD and were admitted for intravenous gamma globulin (IVIG) treatment at the Kaohsiung Chang Gung Memorial Hospital from 2001 to 2009. Blood samples from KD patients were collected before and after IVIG treatment, and cardiovascular abnormalities were examined by transthoracic echocardiography. Wild-type male BALB/c mice (4-week-old) were intraperitoneally injected with LCWE (1 mg/mL) to induce coronary arteritis. The induced immune response in mice was examined on days 1, 3, 7, and 14 post injections, and histopathology studies were performed on days 7 and 14.

RESULTS

Both human KD patients and LCWE-treated mice developed coronary arteritis, myocarditis, valvulitis, and pericarditis, as well as elevated plasma levels of interleukin (IL)-2, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α in acute phase. Most of these proinflammatory cytokines declined to normal levels in mice, whereas normal levels were achieved in patients only after IVIG treatment, with a few exceptions. Toll-like receptor (TLR)-2, but not TLR4 surface enhancement on circulating CD14+ monocytes, was augmented in KD patients before IVIG treatment and in LCWE-treated mice, which declined in patients after IVIG treatment.

CONCLUSION

This result suggests that that not only TLR2 augmentation on CD14+ monocytes might be an inflammatory marker for both human KD patients and LCWE-induced CAL mouse model but also this model is feasible for studying therapeutic strategies of coronary arteritis in human KD by modulating TLR2-mediated immune activation on CD14+ monocytes.

Pattern recognition receptors involved in the inflammatory attenuating effects of soybean isoflavone in β-amyloid peptides 1-42 treated rats

Pattern recognition receptors (PRRs) play important roles in the inflammatory responses to Alzheimer's disease (AD). Our previous study indicated that soybean isoflavone (SIF) exhibited anti-inflammatory effect in rats treated by β-amyloid peptides1-42 (Aβ1-42). In present study, we further detected the effects of SIF against inflammation caused by Aβ1-42 treatment in rats. Serum inflammatory mediators and neurotrophic factors including transforming growth factor-β (TGF-β), inducible nitric oxide synthase (iNOS), brain-derived neurotrophic factor (BDNF) and S100β were detected by enzyme-like immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR) and western blot methods were applied for detecting mRNA and protein expression of interleukin-1β (IL-1β), iNOS, tumor necrosis factor-α (TNF-α), TGF-β, BDNF, S100β, myeloid differentiation factor88 (Myd88), Toll-like receptor2 (TLR2), formyl peptide receptors (FPRs), inhibitor κB kinase (IKK) and inhibitor κB-α (IκB-α) in rat's brain tissue. Our results indicated that SIF could reduce the production of IL-1β, TNF-α and iNOS induced by Aβ1-42 in serum and brain of rats. SIF also significantly reversed Aβ1-42-induced up-regulation of TLR2, FPR, Myd88, IKK and decreased IκB-α mRNA and protein expressions in rats. These results suggested that TLR2 and FPR might involve in the inflammatory process induced by Aβ1-42 treatment, and SIF was an efficiency compound in reversing the inflammation caused by Aβ1-42 treatment.

Toll-like receptor (TLR) 2 is upregulated on peripheral blood monocytes of patients with psoriatic arthritis: a role for a gram-positive inflammatory trigger?

Toll-like receptor (TLR) 2 and TLR4 are able to activate innate immune cells in response to gram-positive and gramnegative bacteria, respectively. Psoriatic arthritis (PsA) is a chronic inflammatory joint disease and gram-positive streptococcus may have a role in its pathogenesis, suggesting the importance of TLR2 stimulation in PsA.

OBJECTIVES

To assess TLR2 and TLR4 expressions on innate immune cells of PsA patients, relating to clinical disease activity.

METHODS

Forty-five patients with peripheral joint manifestations of PsA were included and disease activity was assessed by Disease Activity Score of 28 joint counts (DAS28). 32 healthy subjects constituted the control group. Membrane-bound TLR2 and TLR4 expressions were assessed on peripheral blood monocytes and neutrophils by flow cytometry.

RESULTS

Twenty-seven patients had active PsA (DAS28 higher than 2.6) and 18 had inactive disease. TLR2 was significantly upregulated on monocytes in both active and inactive PsA group, comparing to healthy controls. TLR4 was similarly expressed in all tested groups.

CONCLUSIONS

TLR2 is overexpressed by PsA monocytes, suggesting that gram-positive exposure could induce higher inflammatory responses in this disease.

Hyaluronan reduces inflammation in experimental arthritis by modulating TLR-2 and TLR-4 cartilage expression

Previous studies have reported that low molecular mass HA and highly polymerized HA respectively elicited pro- and anti-inflammatory responses by modulating the toll-like receptor 4 (TLR-4) and the TLR-2. The activation of TLR-4 and TLR-2 mediated by collagen-induced arthritis (CIA) induces the myeloid differentiation primary response protein (MyD88) and the tumor necrosis factor receptor-associated factor 6 (TRAF6), and ends with the liberation of NF-kB which, in turn, stimulates pro-inflammatory cytokine production. The aim of this study was to investigate the influence of high molecular weight HA at different concentrations on TLR-4 and TLR-2 modulation in CIA in mice. Arthritis was induced in mice via intradermal injection of an emulsion containing bovine type II collagen in complete Freund's adjuvant. Mice were treated with HA intraperitoneally daily for 30days. CIA increased TLR-4, TLR-2, MyD88 and TRAF6 mRNA expression and the related protein in the cartilage of arthritic joints. High levels of both mRNA and related protein were also detected for tumor necrosis factor alpha (TNF-α), interleukin 1-beta (IL-1-β), interleukin-17 (IL-17), matrix metalloprotease-13 (MMP-13) and inducible nitric oxide synthase (iNOS) in the joint of arthritic mice. HA treatment significantly limited CIA incidence and decreased all the parameters up-regulated by CIA. The improvement of biochemical parameters was also supported by histological analysis, plasma and synovial fluid HA levels. These results suggest that the TLR-4 and TLR-2 play an important role in the arthritis mechanism and the interaction/block of HA at high molecular mass may reduce inflammation and cartilage injury.

[Variations of HBD-2 and TLR-2 gene expression in patients presenting with lichen ruber planus under effect of ultraviolet irradiation]

The combination of narrow-band range UV-A (311 nm) and middle/broad-band UV-B (320-400 nm) irradiation was shown to significantly reduce manifestations of objective and subjective symptoms in the patients presenting with lichen ruber planus. Moreover, it promoted elimination ofdisbalance between characteristics of congenital immunity and normalization of HBD-2 and TLR-2 gene expression.

Tolerogenic T cells, Th1/Th17 cytokines and TLR2/TLR4 expressing dendritic cells predominate the microenvironment within distinct oral mucosal sites

BACKGROUND

Most local oral vaccine strategies use the sublingual region for drug application. Only little is known about the cytokine micromilieu, the nature of T cell subtypes and expression of target structures for adjuvants at different oral mucosal regions (OMR). However, targeting the optimal OMR might ensure highest efficiency of drug uptake and lowest risk for adverse effects.

METHODS

Expression of TGF-β1, IL10 as well as Th1, Th2 and Th17 cytokines and transcription factors was investigated at different OMR and skin by quantitative real-time PCR, immunohistochemistry or flow cytometry.

RESULTS

Highest number of T cells was located in vestibular/buccal region (VBR). In contrast to skin (SK), OMR T cells produced TGF-β1, IL-10, IFN-γ and IL-17. Significantly higher TGF-β1 mRNA expression in the VBR compared with the sublingual region (SLR) and skin could be detected, while equal transcripts of IL-10 and regulatory T cell-associated transcription factor FoxP3 could be demonstrated. Expression of Th17-associated IL-17A, IL-17F, IL-22 and IL-26 mRNA could be demonstrated in VBR and SLR but not in SK. Interestingly, compared to SK, significantly higher expression of TGF-β1 and IFN-γ could be detected in OMR. Moreover, expression of toll-like receptor (TLR) 2 and TLR4 was highest in VBR with significant expression on dendritic cells in OMR.

CONCLUSION

From this data, we conclude that (i) VBR and SLR represent a protolerogenic micromilieu, (ii) both regions form a Th1 cytokine-predominated microenvironment, but also express mRNA for Th17 cytokines and (iii) TLRs detectable in VBR and SLR might serve as a target structures for adjuvants.

Upregulation of TLR2 expression on G-CSF-mobilized peripheral blood stem cells is responsible for their rapid engraftment after allogeneic hematopoietic stem cell transplantation

Granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSCs) are more frequently used as the cellular source in allogeneic hematopoietic stem cell transplantation (HSCT) than bone marrow stem cells (BMSCs) because they promote more rapid engraftment and immune reconstitution. However, the underlying mechanism for this is not fully understood. Here, we investigated the role of Toll-like receptor 2 (TLR2) on PBSCs in promoting rapid engraftment after allogeneic HSCT. We found that PBSCs highly expressed TLR2 in comparison to BMSCs, and TLR2 was directly induced by G-CSF signaling. Treatment with the TLR2 ligand, Pam(3)CSK(4) (PAM), more efficiently induced myeloid differentiation of PBSCs than BMSCs. Similarly, endogenous TLR2 ligands from the serum of recipients of allogeneic transplantation more rapidly stimulated myeloid differentiation of PBSCs compared with BMSCs. PAM treatment of TLR2(-/-) syngeneic recipient mice transplanted with PBSCs resulted in significantly elevated numbers of PBSC-derived myeloid cells and spleen colony formation compared with controls. Our results demonstrate that TLR2 signaling in PBSCs correlates with their ability to rapidly differentiate into myeloid cells, resulting in improved engraftment. Thus, TLR2 may be a novel target for increasing the efficiency of allogeneic HSCT by overcoming engraftment failure or delayed engraftment.

[Experimental study on anti-inflammatory effect of adenovirus-mediated sTLR2 in LPS-induced murine inflammation]

AIM

To observe the anti-inflammatory effect of adenovirus-mediated sTLR2 in LPS-induced murine inflammation, and to provide a new thinking and tactics of prevention and treatment for acute inflammatory reaction.

METHODS

Murine inflammation model induced by LPS (lethal dose) was established. BALB/c mice were divided into normal control group, inflammation model group and AdTLR2 treatment group. The recombinant adenovirus (Ad)TLR2 acted on test mice respectively before and after inflammation production, the impact of AdTLR2 on murine survival time was observed. Serum samples of different experiment groups were collected, alteration of cytokine TNF-alpha, IL-1beta, IL-6, IL-10 and IL-13 were tested by ELISA, the influence of AdTLR2 on serum level of cytokines were evaluated.

RESULTS

A prolonged survival time by AdTLR2 was observed on lethal dose of LPS animal model; serum level of TNF-alpha, IL-1beta, IL-6, IL-10 and IL-13 were reduced by AdTLR2 on LPS induced murine model, indicating a certain immuno-regulation and anti-inflammatory effect of recombinant AdTLR2.

CONCLUSION

Recombinant AdTLR2 resulted a prolong survival time of LPS induced inflammation animal model and reduction of serum level of TNF-alpha, IL-1beta, IL-6, IL-10 and IL-13, which achieved a certain immuno-regulation and anti-inflammatory effect.

Bacillus Calmette-Guerin and BCG cell wall skeleton suppressed viability of bladder cancer cells in vitro

AIM

Bacillus Calmette-Guerin (BCG) is one of therapeutic options for urothelial carcinoma (UC). The objectives of this study were to determine the direct effect of viable or heat-killed BCG and BCG cell wall skeleton (BCG-CWS) on UC cells in vitro.

MATERIALS AND METHODS

UC cell lines were co-cultured with viable or heat-killed BCG Immunobladder® (Tokyo 172 strain) and BCG-CWS. Viability of the cells, apoptosis and BrdU incorporation were estimated.

RESULTS

BCG induced cell growth retardation in highly malignant UC bearing integrin α5β1 (VLA5). VLA5-blocking antibody partially abrogated this effect. BCG treatment induced a modest increase in the sub-G(1) fraction of cells and a decrease of BrdU incorporation. Cell growth retardation effect of viable BCG was reproduced by both heat-killed BCG and BCG-CWS.

CONCLUSION

The results indicate that VLA5 may be a biomarker of UC with sensitivity to BCG. Moreover, BCG-CWS is a promising substance which might replace BCG, preventing life-threatening complications of viable BCG treatment.

Interplay of protease-activated receptors and NOD pattern recognition receptors in epithelial innate immune responses to bacteria

Protease-activated receptors (PARs), nucleotide-binding oligomerization domain (NOD) receptors and Toll-like receptors (TLRs) play a role in innate immunity, but little is known about interaction between these receptors. The goal of this study was to investigate how silencing one receptor affects the expression of other receptors and downstream innate immune markers in response to bacteria. Human gingival epithelial cells (GECs) were transfected with siRNA specific for PAR1 or PAR2, then stimulated with periopathogen Porphyromonas gingivalis, bridging organism between pathogens and non-pathogens Fusobacterium nucleatum, or non-pathogen Streptococcus gordonii. PAR1 or PAR2 knock-down resulted in up-regulated NOD1 and NOD2 expression with P. gingivalis or F. nucleatum stimulation (p<0.01), as well as enhanced TLR2 and TLR4 expression when cells were stimulated by bacteria that utilize TLR2 or TLR4, respectively. Involvement of PARs for induction of CC chemokine ligand 20 (CCL20), a cytokine with antimicrobial properties, was observed following stimulation of the three bacterial species. Furthermore, results from multiple cytokine ELISA array showed receptors utilized in the induction of various innate immune markers are tailored to individual bacterium tested. Our data suggest complex interplay of several receptors is required for appropriate innate immune responses to the different types of bacteria present within the oral cavity and that receptor expression itself is altered depending on which organism the cell encounters.

Differential gene expression of gamma-actin, Toll-like receptor 2 (TLR-2) and interleukin-1 receptor-associated kinase 4 (IRAK-4) in Mya arenaria haemocytes induced by in vivo infections with two Vibrio splendidus strains

Immune function gene expression in Mya arenaria haemocytes was evaluated following in vivo infection with Vibrio splendidus LGP32-GFP and 7SHRW. Elongation factor 1alpha (EF-1alpha) with 2 (EF-2), after challenge with LGP32-GFP, and EF-1alpha with the ribosomal protein S-18, after challenge with 7SHRW, were found to be the most stable housekeeping genes. Using these internal controls and comparing the regulation induced by both strains, up-regulation of gamma-actin, down-regulation of TLR-2 and up-regulation of IRAK-4 was significantly higher after challenge with LGP32-GFP (p<0.001, p=0.001 and p<0.05, respectively). These results suggest specific responses at a molecular level modulated by the bacterial strains. LGP32-GFP induced marked responses which coincide with a similar trend previously found on phenotypic responses under our experimental model.

[Induction of dendritic cells maturation by staphylococcal antigens]

AIM

To study the ability to induce dendritic cells maturation obtained from bone marrow of mice by staphylococcal complex of antigens containing bacterial ligands for Toll-like receptors (lipopeptides, lipoproteins, and peptidoglycans).

MATERIALS AND METHODS

Commercially available TNF-alpha, inductors ofdendritic cells (DCs) maturation, as well C57/BL line mice were used for the study. Immunophenotype of DCs was assessed by flow cytometry and monoclonal antibodies against cellular antigens. Cytological study using phase-contrast microscopy as well as electron microscopy were performed. Levels of cytokines were measured by ELISA.

RESULTS

Obtained DCs had typical morphologic characteristics of mature cells. However the culture was still heterogenous with presence of macrophages that was evident from immunophenotype of obtained cells: CD34(-/+), CD38+, CD40+, CD80+, CD86+, MHC II+, F4/80(-/+). Number of TLR2-expressing cells was also reliably increased in culture of DCs that confirms the presence of corresponding ligands binding with this type of receptor in the preparation. Application of each studied preparation resulted in synthesis of large amount of TNF-alpha, IL-6, IL-1beta, IL-12 by DCs, and IFN-gamma by several types of them (RP and CB24). Although the intensity of induced cytokine synthesis varied for each preparation, it was many times higher compared with immature DCs.

CONCLUSION

High synthesis level and wide spectrum of cytokine production demonstrated that under the influence of bacterial ligands DCs acquired characteristics needed for effective antigen presentation and priming of immune response.

An immunohistochemical study of Toll-like receptors 2 and 4 in placenta with and without infection

OBJECTIVE

The placenta constitutes a physical and immunological barrier against infectious agents. Toll-like receptors (TLRs) are essential components for the induction of innate immunity responses in different human tissues including the placenta. We investigated the expressions of TLR2 and TLR4 in the decidua and amniotic cells in non-inflamed placenta and placenta with infection.

MATERIALS AND METHODS

There were a total 74 placentas (37 with infection and 37 without infection- 25 bacterial, 10 viral and 2 toxoplasma). TLR2 and TLR4 expressions were assessed using immunohistochemical technique. Positive cells were indicated by cytoplasmic staining and the percentage of positive in 100 cells was recorded and graded. The grades were 1+ (< 25%), 2+ (25-75%) and 3+ (> 75%).

RESULTS

We found significantly higher expression of TLR2 in the amniotic cells and decidua cells in infected placentas as compared to non-inflamed placentas among the preterm placenta. A higher number of cases have TLR4 expression in the amnion of preterm infected placenta than in term placenta. This, however, is not statistically significant.

CONCLUSION

Our findings suggest that TLR2 plays a role in the innate immunity in bacterial and viral infection in the placenta, however, their role in protection against toxoplasma may be limited. This study further supports the observations that TLR2 expression was higher in placenta with infection which strengthened the role of TLR2 in the protection of preterm placenta against infection.

Live imaging of Toll-like receptor 2 response in cerebral ischaemia reveals a role of olfactory bulb microglia as modulators of inflammation

Activation of microglial cells in response to ischaemic injury, inflammatory and/or immune stimuli is associated with the marked induction of Toll-like receptor 2 (TLR2). At present, little is known about the spatial and temporal sequence of events, micro-regional specificities and the potential long term role of the TLR2 response to brain injuries. To investigate microglial activation/TLR2 response in real time, we generated a transgenic mouse model bearing the dual reporter system luciferase/green fluorescent protein under transcriptional control of a murine TLR2 promoter. In this model, transcriptional activation of TLR2 was visualized in the brains of live animals using biophotonic/bioluminescence molecular imaging and a high resolution/sensitivity charged coupled device camera. It was found that TLR2 induction/microglial activation has a marked chronic component after ischaemic injury and may last several months after the initial attack. The pro-inflammatory response was not restricted to the site of ischaemic injury but was also evident in the olfactory bulb. A significant TLR2 response was first seen in the olfactory bulb 6 h after stroke and several hours before the increase in photon emission over the site of infarction. This sequence of events was further confirmed by immunohistochemistry. A similar early TLR2 response from olfactory bulb microglia was observed in the brain's immune response to pathogens. We therefore propose that, owing to their unique situation, receiving and translating numerous inputs from the brain as well as from the environment, olfactory bulb microglia may serve as sensors and/or modulators of brain inflammation.

Expression of toll-like receptor 2 on peripheral blood monocytes of patients with inflammatory and noninflammatory acne vulgaris

The pathogenesis of acne vulgaris is multifactorial and entails the interplay of hormonal, microbial and immunological events. The bacterium Propionibacterium acnes is involved in the induction of comedogenesis and maintenance of the inflammatory phase of acne. Toll-like Receptor 2 (TLR2) expressed on mononuclear inflammatory cells and possibly on keratinocytes and sebocytes is thought to be of vital importance in mediating P. acnes-induced inflammatory response in acne vulgaris. This work aimed to study the degree of expression of TLR2 on peripheral blood monocytes (PBM) from patients with non-inflammatory and inflammatory acne and to investigate the influence of systemic isotretinoin therapy on TLR2 expression. Sixteen patients with predominantly non-inflammatory acne, 16 patients with predominantly inflammatory acne and 16 age and sex matched healthy subjects were involved in this study. Cell surface expression of CD14 and TLR2 were determined by cell surface staining and flowcytometry. TLR2 expression was analyzed for 12 patients with severe and/or scaring inflammatory acne after oral isotretinoin therapy for two months. The mean fluorescence intensity (MFI) of TLR2 on PBM reported a statistically significant difference between patients with non-inflammatory acne, patients with inflammatory acne and control subjects. MFI of TLR was significantly lower for patients with inflammatory acne after systemic isotretinoin therapy. Data obtained suggest that TLR2 expression on PBM is an important event in acne pathogenesis and targeting this molecule might be a useful therapeutic goal in the future.

Role of Interleukin-6 in Toll-Like Receptor 4 and 2 Expressions Induced by Lipopolysaccharide in the Lung

Our previous study demonstrated that interleukin (IL)-6 is protective against hemorrhagic lung inflammation induced by lipopolysaccharide (LPS) in mice, at least partly, by inhibition of the enhanced expressions of proinflammatory cytokines. The present study elucidated the role of IL-6 in Toll like receptor (TLR) 4 and 2 expressions in the lung during inflammation induced by intraperitoneal administration of LPS (1 mg/kg) using IL-6 null (-/-) mice and wild type (WT) mice. The expressions of mRNA for both TLR4 and 2 in the lung were evaluated 72 hrs after intraperitoneal administration. LPS enhanced both TLR4 mRNA expression as compared with vehicle. However, the enhancement was significantly stronger in IL-6 (-/-) mice than in WT mice after LPS challenge. LPS significantly increased TLR2 mRNA expression only in IL-6 (-/-) mice. As well, in the presence of LPS, the expression was significantly greater in IL-6 (-/-) mice than in WT mice. These results suggest that the protective role of IL-6 against LPS-induced hemorrhagic lung inflammation might be explained, in part, by inhibition of the enhanced lung expressions of TLR4 and 2.

Decreased numbers of FoxP3-positive and TLR-2-positive cells in intestinal mucosa are associated with improvement in patients with active inflammatory bowel disease following selective leukocyte apheresis

BACKGROUND

Impaired immunological tolerance to commensal enteric flora is considered one possible pathogenic mechanism of inflammatory bowel disease (IBD). Given that regulatory T cells and Toll-like receptor (TLR)-positive cells are key actors in mucosal immune regulation, we aimed to identify the dynamics of these actors in the intestinal mucosa in relation to clinical improvement following selective leukapheresis treatment.

METHODS

Ten patients with active IBD despite treatment with corticosteroids, immunomodulators, or anti-tumor necrosis factor therapy were assessed by immunohistochemical staining of colorectal mucosal biopsies obtained before and after five sessions (week 7) of granulocyte and monocyte adsorption apheresis (GCAP). The presence of FoxP3-positive regulatory T cells, macrophages, dendritic cells, and TLR-2 and-4 positive cells was determined in relation to short-(week 7) and long-term (week 52) clinical outcome data.

RESULTS

Following GCAP, the number of FoxP3-(P = 0.012) and TLR-2 (P = 0.008)-positive cells significantly decreased in biopsies after 7 weeks, in parallel with both clinical improvement at week 7 and a longstanding response after 12 months.

CONCLUSIONS

Downregulation of FoxP3 and TLR-2 cells in the colorectal mucosa mirrors both short-and long-term improvement in patients with active IBD responding to GCAP. This observation suggests a potential role of these cells in the pathogenesis of IBD and the induction of immunological tolerance in the mucosa.