BACKGROUNDToll-like receptors play an important role in the human immune system. This study was conducted to investigate the expression profiles and function of Toll-like receptor (TLR) 1 - 9 in human corneal epithelium.

METHODSThe expression of TLR1 - 9 mRNA in 20 human donor corneal epithelia samples abraded during photorefractive keratotomy (PRK) and cultivated telomerase-immortalized human corneal epithelial cells (THCEs) was examined by semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis. Human peripheral blood mononuclear cells (PBMCs) were used as positive controls. The expression of the TLR2 and TLR4 proteins was detected by Western analysis. ELISA was used to detect IL-8 secretion from THCEs challenged with ligands for TLR3 and TLR4 with and without antibody blockade.

RESULTSThe expression of TLR1 - 9 at the mRNA level was detected in the epithelia of 20 patients and in THCE. Significant differences among individuals were observed. One patient was found to lack of the expression of TLR3, 4, 6 and 8, whereas another did not express TLR5. The expression of TLR2 and TLR4 protein was detected in human corneal epithelial cells. As THCE cells express TLR1 - 9, cells were challenged with lipopolysaccharides (LPS) and poly I:C to determine whether TLR4 and TLR3 were functional. The results showed that secretion of IL-8 by cells stimulated with LPS and Poly I:C was 7 to 10 fold greater than secretion by unchallenged cells. Blocking TLR4 with an anti-TLR4 antibody significantly inhibited the LPS-induced IL-8 production by THCE (P < 0.05).

CONCLUSIONHuman corneal epithelial cells express multiple TLRs and are able to recognize LPS and poly I:C. Different expression profiles among individuals suggest that differences in the susceptibilities and sensitivities to bacterial and viral infection in human populations relate to different patterns of TLR expression.

Blotting, Western ; Epithelium, Corneal ; metabolism ; Humans ; Lipopolysaccharides ; pharmacology ; Poly I-C ; pharmacology ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Toll-Like Receptors ; analysis ; genetics ; physiology

BACKGROUNDExcessive iodine intake and viral infection are recognized as both critical factors associated with autoimmune thyroid diseases. Toll-like receptors (TLRs) have been reported to play an important role in autoimmune and inflammatory disorders. In this study, we aimed to clarify the possible mechanism of TLR3 involved in polyinosine-polycytidylic acid (poly(I:C)) promoting excessive iodine intake induced thyroiditis in non-obese diabetic (NOD) mice.

METHODSBoth NOD and BALB/c mice were randomly assigned to four groups: control group (n = 5), high iodine intake (HI) group (n = 7), poly(I:C) group (n = 7) and combination of excessive iodine and poly(I:C) injection (HIP) group (n = 7). After 8 weeks, mice were weighed and blood samples were collected. All the mice were sacrificed before dissection of spleen and thyroid gland. Then, thyroid histology, thyroid secreted hormone, expression of CD3(+) cells and TLR3 as well as inflammatory mRNA level were evaluated.

RESULTSBoth NOD and BALB/c mice from HI and HIP group represented goiter and increasing thyroid relative weight. Thyroid histology evidence indicated that only HIP group of NOD mice showed severe thyroiditis with lymphocytes infiltration in majority of thyroid tissue, severe damage of follicles and general fibrosis. Immunofluorescence staining results displayed a large number of CD3(+) cells in HIP NOD mice. Real-time polymerase chain reaction (PCR) results suggested interferon (IFN)-α increased over 30 folds and IFN-γ expression was doubled compared with control group, but interleukin (IL)-4 remained unchanged in HIP group of NOD mice thyroid. Meanwhile, over one third decrease of blood total thyroxine (TT4) and increased thyroid-stimulating hormone (TSH) was observed in HIP group of NOD mice. Only HIP group of NOD mice represented significantly elevation of TLR3 expression.

CONCLUSIONPoly(I:C) enhanced excessive dietary iodine induced thyroiditis in NOD mice through increasing TLR3 mediated inflammation.

Animals ; Female ; Inflammation ; chemically induced ; metabolism ; Iodine ; toxicity ; Mice ; Mice, Inbred NOD ; Poly I-C ; pharmacology ; Thyroiditis ; chemically induced ; immunology ; metabolism ; Toll-Like Receptor 3 ; metabolism

OBJECTIVETo investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.

METHODSSixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.

RESULTSCompared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).

CONCLUSIONSViral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.

Animals ; Asthma ; etiology ; Bronchoalveolar Lavage Fluid ; chemistry ; Female ; Lung ; pathology ; Matrix Metalloproteinase 9 ; analysis ; Mice ; Mice, Inbred BALB C ; Poly I-C ; pharmacology ; Respiratory Syncytial Virus Infections ; complications ; Tissue Inhibitor of Metalloproteinase-1 ; analysis

OBJECTIVETo investigate the effects of polyinosinic-polycytidylic acid (polyI:C) on the production of thymic stromal lymphopoietin (TSLP) and airway inflammation in mice with exacerbated asthma induced by respiratory syncytial virus (RSV).

METHODSThirty-two female BALB/c mice were randomly divided into 4 groups, namely the PBS control group, OVA group, OVA/RSV group, and OVA/RSV/polyI:C group. In the latter 3 groups, the mice were sensitized by OVA and stimulated with nebulized OVA. RSV was inoculated into the nasal cavity of the sensitized mice and polyI:C (1 mg/kg) was intramuscularly administered. The airway response to metacholine was examined, and the serum levels of IL-4, IL-5, IL-13, and IFN-γ and TSLP in the supernatants of bronchoalveolar lavage fluid (BALF) were detected using ELISA. The total BALF cells, eosinophils, lymphocytes and neutrophils were counted. The lung specimens were collected to observe the inflammation with HE staining, and immunohistochemistry was employed to determine TSLP production in the airway epithelial cells.

RESULTSThe mice in RSV/OVA/polyI:C group showed a significantly lower airway responsiveness to metacholine than those in OVA/RSV group (P<0.01). Compared with OVA/RSV group, RSV/OVA/polyI:C group showed significantly lower serum levels of IL-4, IL-5, IL-13 and TSLP in BALF (P<0.05), with also lower total BALF cells, eosinophils and lymphocytes (P<0.05) and lessened infiltration of the airway inflammatory cells. Immunohistochemistry of TSLP also demonstrated a lower production of TSLP in the airway epithelial cells in RSV/OVA/polyI:C group than in OVA/RSV group.

CONCLUSIONSpolyI:C can inhibit the increase in TSLP production in the airway epithelial cells after RSV infection and relieve airway inflammation in mice with RSV-induced asthma exacerbation.

Animals ; Asthma ; blood ; metabolism ; virology ; Bronchoalveolar Lavage Fluid ; Cytokines ; secretion ; Female ; Inflammation ; pathology ; Interleukin-13 ; blood ; Interleukin-4 ; blood ; Interleukin-5 ; blood ; Mice ; Mice, Inbred BALB C ; Poly I-C ; pharmacology ; Respiratory Syncytial Virus Infections ; blood ; metabolism ; Respiratory Syncytial Viruses

OBJECTIVETo study the expression of Toll-like receptors (TLRs) mRNA in human trophoblast HTR-8/SVneo cells and the changes in indoleamine 2,3-dioxygenase (IDO) mRNA expression in response to TLR ligand stimulation.

METHODSThe expressions of TLRs and IDO mRNA in human HTR-8/SVneo cells were tested by RT-PCR, and the changes in IDO mRNA levels after exposure to TLR3, TLR4, TLR7/8, and TLR9 ligands were quantitatively analyzed with real-time PCR.

RESULTSIDO and TLR1-10 mRNAs were expressed in HTR-8/SVneo cells. As the cell culture time extended, IDO mRNA expression level tended to increase within 48 h. After stimulation with the TLR ligands, the expression of TLR-3 mRNA was down-regulated while the expression of TLR-4, 7, 8, and 9 mRNA up-regulated. Stimulation of the cells with poly(I:C) lowered the expression of IDO mRNA while IFN-γ increased its expression.

CONCLUSIONSThe expression of IDO mRNA is associated with the nutrition of the maternal-fetal interface. Stimulation with the TLR ligands affects the expression of IDO and TLR mRNA expressions in the cells, which verifies the functional activity of TLRs and suggests a role of IDO in TLR pathway-dependent antiviral immunity.

Cell Line ; Female ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; genetics ; metabolism ; Interferon-gamma ; pharmacology ; Ligands ; Poly I-C ; pharmacology ; RNA, Messenger ; metabolism ; Toll-Like Receptors ; genetics ; metabolism ; Trophoblasts ; cytology ; metabolism

Objective: To explore the effect and mechanism of activation of peripheral blood mononuclear cell (PBMC) Toll-like receptor (TLR3) signaling pathway in recombinant HBsAg (rHBsAg) immune response. Methods: White blood cells were collected from peripheral blood of 13 healthy donors in the preparation of blood products. PBMC was isolated and treated with Poly I:C (Poly I:C group) and PBS (control group) respectively. 48 h later, some cells were collected and the expressions of TLR3 signaling pathway proteins were detected by flow cytometry. After activating (Poly I:C group)/inactivating (control group) TLR3 signaling pathway, rHBsAg was given to both groups for 72 h, and the proportions of DC, T, B cells and their subsets in PBMC were detected by flow cytometry. Paired <i>ti>-test, paired samples wilcoxon signed-rank test and canonical correlation analyses were used for statistical analysis. Results: The percentage of TLR3 protein-positive cells (19.21%) and protein expression (8 983.95), NF-κB protein expression (26 193.13), the percentage of pNF-κB protein-positive cells (13.73%) and its proportion in NF-κB (16.03%), and the percentage of pIRF3 protein-positive cells (12.64%) and its proportion in IRF3 (21.80%) in Poly I:C group were higher than those in control group (11.54%, 8 086.00, 22 340.66, 8.72%, 9.71%, 9.57%, 19.12%) (<i>Pi><0.05), and the percentage of TRIF protein-positive cells (89.75%) and protein expression (304 219.54) were higher in Poly I:C group than in the control group (89.64%, 288 149.72) (<i>Pi>>0.05). After PBMC stimulation by rHBsAg, the proportions of mDC (2.90%), pDC (1.80%), B cell (5.31%) and plasma cell (67.71%) in Poly I:C group were significantly higher than those in the control group (1.83%, 0.81%, 4.23%, 58.82%) (<i>Pi><0.05). Results of canonical correlation analysis showed that the expression of TLR3 protein was positively correlated with the proportions of plasma cells, the expression of pIRF3 protein was positively correlated with the proportions of plasma cells and mDC, and the percentage of pNF-κB protein-positive cells and the percentage of pIRF3 protein-positive cells were positively correlated with the proportion of CD4⁺T cells. Conclusions: Poly I:C can activate TLR3/TRIF/NF-κB and TLR3/TRIF/IRF3 signaling pathway, promote the function of downstream signaling molecules, and then promote the maturation of DC, induce the immune responses of CD4⁺T cell, and promote the maturation and activation of B cells and the immune response of rHBsAg.
Adaptor Proteins, Vesicular Transport/pharmacology* ; Hepatitis B Surface Antigens ; Humans ; Immunity ; Leukocytes, Mononuclear/metabolism* ; NF-kappa B ; Poly I-C/pharmacology* ; Signal Transduction ; Toll-Like Receptor 3/metabolism* ; Toll-Like Receptors

Indoleamine 2,3-dioxygenase (IDO) is a key negative regulator of immune responses and has been implicated in tumor tolerance, autoimmune disease and asthma. IDO was detected in the joint synovial tissue in the inflammatory microenvironment of rheumatoid arthritis (RA), but IDO expression in joint synovial tissue is not sufficient to overcome the inflamed synovial environment. This study aimed to unravel the mechanisms involving the failure to activate tolerogenic IDO in the inflamed joint. We demonstrate that both poly (I:C) and lipopolysaccharide (LPS) induce expression of IDO in synovial fibroblasts. However, inflammatory cytokines such as IL-17, TNF-alpha, IL-12, IL-23 and IL-16 did not induce IDO expression. Poly (I:C) appeared to induce higher IDO expression than did LPS. Surprisingly, toll-like receptor (TLR)4-mediated IDO expression was upregulated after depletion of myeloid differentiation primary response protein 88 (MyD88) in synovial fibroblasts using small interfering RNA (siRNA). IDO, TLR3 and TLR4 were highly expressed in synovial tissue of RA patients compared with that of osteoarthritis patients. In addition, RA patients with severe disease activity had higher levels of expression of IDO, TLR3 and TLR4 in the synovium than patients with mild disease activity. These data suggest that upregulation of IDO expression in synovial fibroblasts involves TLR3 and TLR4 activation by microbial constituents. We showed that the mechanisms responsible for IDO regulation primarily involve MyD88 signaling in synovial fibroblasts, as demonstrated by siRNA-mediated knockdown of MyD88.
Adaptor Proteins, Vesicular Transport/genetics/metabolism ; Arthritis, Rheumatoid/*metabolism ; Blotting, Western ; Cells, Cultured ; Fibroblasts/drug effects/*metabolism ; Humans ; Immunohistochemistry ; Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics/*metabolism ; Interleukin-12/pharmacology ; Interleukin-16/pharmacology ; Interleukin-17/pharmacology ; Interleukin-23/pharmacology ; Lipopolysaccharides/pharmacology ; Myeloid Differentiation Factor 88/genetics/*metabolism ; Poly I-C/pharmacology ; Polymerase Chain Reaction ; RNA, Small Interfering/genetics/physiology ; Synovial Membrane/*cytology ; Toll-Like Receptor 4/genetics/metabolism ; Tumor Necrosis Factor-alpha/pharmacology

OBJECTIVEChronic rhinosinusitis was often exacerbated by viral infection. A disruption of the mechanisms that regulate the activity of matrix metalloproteinases (MMPs) during viral infection was one possible mechanism responsible for the exacerbation. The purpose of study was to achieve a better understanding of MMP expression in nasal epithelial cells after viral infection.

METHODSHuman nasal epithelial cells were isolated from nasal polyp specimens obtained during endoscopic endonasal surgery in chronic rhinosinusitis patients. The expression of MMP-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 mRNA in primary human nasal polyp epithelial cells after double stranded RNA (ds RNA) stimulation were investigated.

RESULTSAmong the genes whose expression was evaluated, only expression of MMP-9 mRNA increased significantly after dsRNA stimulation (22.61 +/- 5.47 fold increase, Z = -2.52, P = 0.012).

CONCLUSIONSThe significant up-regulation of MMP-9 mRNA, which was not modulated by TIMP-1, was an additional source of increased proteolytic activity in virus-infected upper airways that might contribute to the exacerbation of chronic rhinosinusitis with nasal polyps.

Cells, Cultured ; Epithelial Cells ; metabolism ; Gene Expression Regulation, Enzymologic ; Humans ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Nasal Polyps ; genetics ; metabolism ; Poly I-C ; pharmacology ; RNA, Double-Stranded ; genetics ; RNA, Messenger ; genetics ; Sinusitis ; genetics ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism

OBJECTIVETo explore the effect and mechanism of Poly I:C in inducing growth inhibition and apoptosis of human hepatocellular carcinoma SMMC-7721 cells.

METHODSSMMC-7721 cells were treated with different doses of Poly I:C for 24, 48, and 72 h, and the cell growth inhibition rate was analyzed with CCK-8 assay. The cell cycle and the apoptosis were analyzed using flow cytometry with Annexin-V and PI staining, and quantitative RT-PCR analysis were used to detect the expression of TLR3, TRIF, and IFN-beta mRNA in cells.

RESULTSIn the cells exposed to Poly I:C at low, moderate, and high doses, the inhibitory rates was the highest in high-dose Poly I:C group, and at a given Poly I:C dose, prolonged exposure resulted in significantly increased cell growth inhibition rate (P<0.05). Flow cytometry showed that Poly I:C induced cell apoptosis in a time- and dose-dependent manner and significantly increased the percentage of G1-phase cells as compared with that in the control group. The mRNA level of TLR3, TRIF, and IFN-beta were also increased following Poly I:C treatment in comparison with the control group.

CONCLUSIONPoly I:C can induce significant growth inhibition and apoptosis of SMMC-7721 cells in a dose- and time-dependent manner possibly by causing cell cycle arrest and TLR3 signaling pathway activation that leads to IFN-beta production and cell apoptosis.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Interferon-beta ; genetics ; metabolism ; Liver Neoplasms ; pathology ; Poly I-C ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Receptors, Cholecystokinin ; metabolism ; Signal Transduction ; Toll-Like Receptor 3 ; genetics ; metabolism

PURPOSE: Tripartite-motif-containing protein 56 (TRIM56) has been found to exhibit a broad antiviral activity, depending upon E3 ligase activity. Here, we attempted to evaluate the function of TRIM56 in multiple myeloma (MM) and its underlying molecular basis. MATERIALS AND METHODS: TRIM56 expression at the mRNA and protein level was measured by qRT PCR and western blot analysis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry analysis was performed to investigate the effect of TRIM56 on MM cell proliferation and apoptosis. The concentrations of interferon (IFN)-β, interleukin (IL)-6, and tumor necrosis factor-α in MM cell culture supernatants were detected with respective commercial ELISA kits. Western blot was employed to determine the effect of TRIM56 on toll-like receptor 3 (TLR3)/toll-IL-1 receptor (TIR) domain-containing adaptor inducing IFN-β (TRIF) signaling pathway. RESULTS: TRIM56 expression was prominently decreased in MM cells. Poly (dA:dT)-induced TRIM56 overexpression in U266 cells suppressed proliferation, induced apoptosis, and enhanced inflammatory cytokine production, while TRIM56 knockdown improved growth, diminished apoptosis, and inhibited inflammatory cytokine secretion in RPMI8226 cells. Moreover, TRIM56 knockdown blocked TLR3 signaling pathway. Furthermore, poly (I:C), a TLR3 agonist, markedly abolished TRIM56 depletion-induced increase of proliferation, decrease of apoptosis, and reduction of inflammatory factor in MM cells. CONCLUSION: TRIM56 may act as a tumor suppressor in MM through activation of TLR3/TRIF signaling pathway, contributing to a better understanding of the molecular mechanism of TRIM56 involvement in MM pathogenesis and providing a promising therapy strategy for patients with MM.
Adaptor Proteins, Vesicular Transport/metabolism ; Apoptosis/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cytokines/secretion ; Disease Progression ; Down-Regulation/drug effects ; Gene Knockdown Techniques ; Humans ; Multiple Myeloma/metabolism ; Multiple Myeloma/pathology ; Poly I-C/pharmacology ; Signal Transduction/drug effects ; Toll-Like Receptor 3/metabolism ; Tripartite Motif Proteins/deficiency ; Tripartite Motif Proteins/metabolism ; Ubiquitin-Protein Ligases/deficiency ; Ubiquitin-Protein Ligases/metabolism