Effects of Xinjiaxiangruyin on the TLR7 pathway in influenza virus-infected lungs of mice housed in a hygrothermal environment.

BACKGROUND: To investigate the effects and immunological mechanisms of the traditional Chinese medicine Xinjiaxiangruyin on controlling influenza virus (FM1 strain) infection in mice housed in a hygrothermal environment. METHODS: Mice were housed in normal and hygrothermal environments, and intranasally infected with influenza virus (FM1). A high-performance liquid chromatography fingerprint of Xinjiaxiangruyin was used to provide an analytical method for quality control. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to measure messenger RNA expression of Toll-like receptor 7 (TLR7), myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF-κB) p65 in the TLR7 signaling pathway and virus replication in the lungs. Western blotting was used to measure the expression levels of TLR7, MyD88, and NF-κB p65 proteins. Flow cytometry was used to detect the proportion of Th17/T-regulatory cells. RESULTS: Xinjiaxiangruyin effectively alleviated lung inflammation in C57BL/6 mice in hot and humid environments. Guizhimahuanggebantang significantly reduced lung inflammation in C57BL/6 mice. The expression of TLR7, MyD88, and NF-κB p65 mRNA in lung tissue of WT mice in the normal environment, GZMHGBT group was significantly lower than that in the model group (P < 0.05). In WT mice exposed to the hot and humid environment, the expression levels of TLR7, MyD88, and NF-κB p65 mRNA in the XJXRY group were significantly different from those in the virus group. The expression levels of TLR7, MyD88, and NF-κB p65 protein in lung tissue of WT mice exposed to the normal environment, GZMHGBT group was significantly lower than those in the model group. In WT mice exposed to hot and humid environments, the expression levels of TLR7, MyD88, and NF-κB p65 protein in XJXRY group were significantly different from those in the virus group. CONCLUSION: Guizhimahuanggebantang demonstrated a satisfactory therapeutic effect on mice infected with the influenza A virus (FM1 strain) in a normal environment, and Xinjiaxiangruyin demonstrated a clear therapeutic effect in damp and hot environments and may play a protective role against influenza through downregulation of the TLR7 signal pathway.

Injured liver-released miRNA-122 elicits acute pulmonary inflammation via activating alveolar macrophage TLR7 signaling pathway.

Hepatic injury is often accompanied by pulmonary inflammation and tissue damage, but the underlying mechanism is not fully elucidated. Here we identify hepatic miR-122 as a mediator of pulmonary inflammation induced by various liver injuries. Analyses of acute and chronic liver injury mouse models confirm that liver dysfunction can cause pulmonary inflammation and tissue damage. Injured livers release large amounts of miR-122 in an exosome-independent manner into the circulation compared with normal livers. Circulating miR-122 is then preferentially transported to mouse lungs and taken up by alveolar macrophages, in which it binds Toll-like receptor 7 (TLR7) and activates inflammatory responses. Depleting miR-122 in mouse liver or plasma largely abolishes liver injury-induced pulmonary inflammation and tissue damage. Furthermore, alveolar macrophage activation by miR-122 is blocked by mutating the TLR7-binding GU-rich sequence on miR-122 or knocking out macrophage TLR7. Our findings reveal a causative role of hepatic miR-122 in liver injury-induced pulmonary dysfunction.

Anti-influenza activity of berberine improves prognosis by reducing viral replication in mice.

Berberine, a natural isoquinoline alkaloid isolated from the berberis species, has a wide array of biological properties such as anti-inflammatory, antibacterial, antifungal, and antihelminthic effects. We evaluated the antiviral effect of berberine against influenza A/FM1/1/47 (H1N1) in vivo and in vitro. The results showed that berberine strongly suppressed viral replication in A549 cells and in mouse lungs. Meanwhile, berberine relieved pulmonary inflammation and reduced necrosis, inflammatory cell infiltration, and pulmonary edema induced by viral infection in mice when compared with vehicle-treated mice. Berberine suppressed the viral infection-induced up-regulation of TLR7 signaling pathway, such as TLR7, MyD88, and NF-κB (p65), at both the mRNA and protein levels. Furthermore, berberine significantly inhibited the viral infection-induced increase in Th1/Th2 and Th17/Treg ratios as well as the production of inflammatory cytokines. Our data provide new insight into the potential of berberine as a therapeutic agent for viral infection via its antiviral activity.

Effects of different principles of Traditional Chinese Medicine treatment on TLR7/NF-κB signaling pathway in influenza virus infected mice.

BACKGROUND: Influenza virus is a single-stranded RNA virus that causes influenza in humans and animals. About 600 million people around the world suffer from influenza every year. Upon recognizing viral RNA molecules, TLR7 (Toll-like receptor) initiates corresponding immune responses. Traditional Chinese Medicines (TCMs), including Yinqiao powder, Xinjiaxiangruyin and Guizhi-and-Mahuang decoction, have been extensively applied in clinical treatment of influenza. Although the therapeutic efficacy of TCMs against influenza virus in vivo was reported previously, its underlying mechanisms are not clearly understood. This study aimed to investigate the immunological mechanisms in the treatment of influenza virus infected mice with three Chinese herbal compounds as well as the effect on TLR7/NF-κB signaling pathway during recovery. METHODS: Wild type and TLR7 KO C57BL/6 mice were infected with influenza virus FM1 and then treated with three TCMs. The physical parameters of mice (body weight and lung index) and the expression levels of components in TLR7/NF-κB signaling pathway were evaluated. RESULTS: After viral infection, Guizhi-and-Mahuang decoction and Yinqiao powder showed better anti-viral effect under normal condition. Compared to the viral control group, expression levels of TLR7, MyD88, IRAK4 and NF-κB were significantly reduced in all treatment groups. Furthermore, the three TCM treatment groups showed poor therapeutic efficacy and no difference in viral load compared to the viral control group in TLR7 KO mice. CONCLUSION: Our study indicated that Guizhi-and-Mahuang decoction and Yinqiao powder might play a crucial role of anti-influenza virus by regulating TLR7/NF-κB signal pathway.

Effects of Gui Zhi Ma Huang Ge Ban Tang on the TLR7 Pathway in Influenza Virus Infected Mouse Lungs in a Cold Environment.

OBJECTIVE: We wished to investigate the effects of the traditional Chinese medicine Gui Zhi Ma Huang Ge Ban Tang on controlling influenza A virus (IAV) infection and improving inflammation in mouse lungs. METHOD: Mice were maintained in normal and cold environments and infected with IAV by intranasal application, respectively. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of TLR7, myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF-κB)p65 in the TLR7 signaling pathway and virus replication in lungs. Western blotting was used to measure expression levels of TLR7, MyD88, and NF-κB p65 proteins. Flow cytometry was used to detect the proportion of T-helper (Th)1/Th2 and Th17/T-regulatory (Treg) cells. RESULTS: Application of Gui Zhi Ma Huang Ge Ban Tang in influenza-infected mice in a cold environment showed (i) downregulation of TLR7, MyD88, and NF-κBp65; (ii) inhibition of transcriptional activities of promoters coding for TLR7, MyD88, and NF-κBp65; (iii) reduction in the proportion of Th1/Th2 and Th17/Treg cells. CONCLUSIONS: Gui Zhi Ma Huang Ge Ban Tang had a good therapeutic effect on mice infected with IAV, especially in the cold environment. It could reduce lung inflammation in mice significantly and elicit an anti-influenza effect by downregulating expression of the key factors in TLR7 signaling pathway.

Hygrothermal environment may cause influenza pandemics through immune suppression.

Over the past few decades, climate warming has caused profound changes in our living environment, and human diseases, including infectious diseases, have also been influenced by these changes. However, it remains unclear if a warm-wet climate can influence the infectivity of influenza and result in influenza pandemics. This study focused on observations of how the hydrothermal environment influences the infectivity of the influenza virus and the resulting immunoreactions of the infected mice. We used a manual climatic box to establish the following 3 environments with different temperatures and humidity: normal environment (T: 24 ± 1°C, RH: 50% ± 4%), wet environment (T: 24 ± 1 °C, RH: 95% ± 4%) and warm-wet environment (T: 33 ± 1 °C, RH: 95% ± 4%), and the mice were fed and maintained in these 3 different environments. After 14 days, half of the mice were infected with H1N1 (A/FM1/1/47, a lung adapted strain of the flu virus specific for the mouse lung) virus for 4 d After establishing the animal model, we observed the microstructure of the lung tissue, the Th1/Th2 T cell subsets, the Th17/Treg balance, the expression of cytokines in the peripheral blood serum and the expression of the immune recognition RLH signal pathway. The results showed that mice in different environments have different reaction. Results showed that after infection, the proportion of Th1/Th2 and Th17/Treg cells in the spleen was significantly increased, and these proportions were increased the most in the infected group kept in wet-hot conditions. After infection, the mRNA levels and protein expression of the RLH (RIG-1-like helicases) signal pathway components were up-regulated while the uninfected animals in the 3 diverse environments showed no significant change. The infected mice kept in the wet and warm-wet environments showed a slight elevation in the expression of RLH pathway components compared to infected mice maintained in the normal environment. Our study suggested that the warm-wet environment may have interfered with the immune response and balance. The mice kept in the warm-wet environment displayed immune tolerance when they were exposed to the influenza virus, and the body was not able to effectively clear the virus, leading to a persistent infection. A warm-wet climate may thus be a factor that contributes to influenza pandemics, people should focus on the warm-wet climate coming and advance prepare to vaccine manufacture.

Dysbiosis of gut microbiota induced the disorder of helper T cells in influenza virus-infected mice.

It is widely understood that commensal microbiota contributes to the maintenance of intestinal homeostasis through dynamic interactions with a body's immunity. And the immune regulation is important for the influenza vaccine's effectiveness after body injection, however, the mechanism between commensal microbiota and vaccine's effectiveness remains unknown. The impact that individual bacteria species have on the balance of the systemic immune system beyond the local intestinal mucosal tissues also remains less clear, and the related mechanism is still unknown. In this study, through the administration of various antibiotics, we examined the balance of helper T cell subsets in mice after inoculating them with the influenza virus and then, attempted to imitate the clinical practice in which patients are always prescribed with an antibiotic treatment in flu season. The data indicates that the mice in each group present differential immune responses in terms of the makeup of helper T cell subsets, although the Th17 cell activity seems to not be involved in the systemic immune modulation in the mice that are susceptible to the intervention of antibiotic. Th1, Th2, and anti-inflammatory regulatory T cells have been implicated in the contribution to the systemic immune response influenced by the antibiotic-induced dysbiosis. Thus we believe that the normal intestinal flora could maintain the immune balance and inhibit the inflammatory responses, which may be useful for clinical application to take intestinal flora into consideration when influenza vaccination was used.

Andrographolide as an anti-H1N1 drug and the mechanism related to retinoic acid-inducible gene-I-like receptors signaling pathway.

OBJECTIVE: To observe the anti-virus effects of andrographolide (AD) on the retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) signaling pathway when immunological cells were infected with H1N1. METHODS: Leukomonocyte was obtained from umbilical cord blood by Ficoll density gradient centrifugation, and immunological cells were harvested after cytokines stimulation. Virus infected cell model was established by H1N1 co-cultured with normal human bronchial epithelial cell line (16HBE). The optimal concentration of AD was defined by methyl-thiazolyl-tetrazolium (MTT) assay. After the virus infected cell model was established, AD was added into the medium as a treatment intervention. After 24-h co-culture, cell supernatant was collected for interferon gamma (IFN-γ) and interleukin-4 (IL-4) enzyme-linked immunosorbent assay (ELISA) detection while immunological cells for real-time polymerase chain reaction (RT-PCR). RESULTS: The optimal concentration of AD for anti-virus effect was 250 µg/mL. IL-4 and IFN-γ in the supernatant and mRNA levels in RLRs pathway increased when cells was infected by virus, RIG-I, IFN-ß promoter stimulator-1 (IPS-1), interferon regulatory factor (IRF)-7, IRF-3 and nuclear transcription factor κB (NF-κB) mRNA levels increased significantly (P<0.05). When AD was added into co-culture medium, the levels of IL-4 and IFN-γ were lower than those in the non-interference groups and the mRNA expression levels decreased, RIG-I, IPS-1, IRF-7, IRF-3 and NF-κB decreased significantly in each group with significant statistic differences (P<0.05). CONCLUSIONS: The RLRs mediated viral recognition provided a potential molecular target for acute viral infections and andrographolide could ameliorate H1N1 virus-induced cell mortality. And the antiviral effects might be related to its inhibition of viral-induced activation of the RLRs signaling pathway.

A novel reporter system for neutralizing and enhancing antibody assay against dengue virus.

BACKGROUND: Dengue virus (DENV) still poses a global public health threat, and no vaccine or antiviral therapy is currently available. Antibody plays distinct roles in controlling DENV infections. Neutralizing antibody is protective against DENV infection, whereas sub-neutralizing concentration of antibody can increase DENV infection, termed antibody-dependent enhancement (ADE). Plaque-based assay represents the most widely accepted method measuring neutralizing or enhancing antibodies. RESULTS: In this study, a novel reporter virus-based system was developed for measuring neutralization and ADE activity. A stable Renilla luciferase reporter DENV (Luc-DENV) that can produce robust luciferase signals in BHK-21 and K562 cells were used to establish the assay and validated against traditional plaque-based assay. Luciferase value analysis using various known DENV-specific monoclonal antibodies showed good repeatability and a well linear correlation with conventional plaque-based assays. The newly developed assay was finally validated with clinical samples from infected animals and individuals. CONCLUSIONS: This reporter virus-based assay for neutralizing and enhancing antibody evaluation is rapid, lower cost, and high throughput, and will be helpful for laboratory detection and epidemiological investigation for DENV antibodies.

Microbiota regulates the TLR7 signaling pathway against respiratory tract influenza A virus infection.

Although intestinal flora are crucial in maintaining immune homeostasis of the intestine, the role of intestinal flora in immune responses at other mucosal surfaces remains less clear. Here, we show that intestinal flora composition critically regulates the toll-like receptor 7 (TLR7) signaling pathway following respiratory influenza virus infection. TLR7 ligands rescued the immune impairment in antibiotic-treated mice. Intact microbiota provided signals leading to the expression of mRNA for TLR7, MyD88, IRAK4, TRAF6, and NF-κB at steady state. Significant changes in the composition of culturable commensal bacteria reduced the expression levels of components of the TLR7 signaling pathway. Our results reveal the importance of intestinal flora in regulating immunity in the respiratory mucosa through the upregulation of the TLR7 signaling pathway for the proper activation of inflammasomes.

Identification and characterization of a linearized B-cell epitope on the pr protein of dengue virus.

The four serotypes of dengue virus (DENV) represent one of the major mosquito-borne pathogens globally; so far no vaccine or specific antiviral is available. During virion maturation, the pr protein is cleaved from its precursor form the prM protein on the surface of immature DENV by host protease. Recent findings have demonstrated that the pr protein not only played critical roles in virion assembly and maturation, but was also involved in antibody-dependent enhancement of DENV infection. However, the B-cell epitopes on the pr protein of DENV have not been well characterized. In this study, a set of 11 partially overlapping peptides spanning the entire pr protein of DENV-2 were fused with glutathione S-transferase and expressed in Escherichia coli. ELISA screening with murine hyperimmune antiserum against immature DENV identified the P8 peptide (57KQNEPEDIDCWCNST7¹) in the pr protein as the major immunodominant epitope. Fine mapping by truncated protein assays confirmed the 8-e peptide 57KQNEPEDI64 was the smallest unit capable of antibody binding. Importantly, the 8-e epitope reacted with sera from dengue fever patients. Site-directed mutagenesis revealed the asparagine residue at position 59 was important for epitope recognition. The 8-e epitope coincided well with the B-cell epitopes predicted by Immune Epitope Database analysis, and 3D structural modelling mapped the 8-e peptide on the surface of prM-E heterodimers. Overall, our findings characterized a linearized B-cell epitope on the pr protein of DENV, which will help to understand the life cycle of DENV and pathogenesis of dengue infections in human.

Study on the anti-H1N1 virus effects of quercetin and oseltamivir and their mechanism related to TLR7 pathway.

The antivirus effect of quercetin and oseltamivir on the Toll-like receptor 7 (TLR7) signaling pathway was observed when dendritic cells and macrophages were infected with H1N1. Leukomonocytes were obtained from umbilical cord blood and harvested after stimulation by recombinant human Granulocyte-Macrophage Colony-Stimulating Factor (rhGM-CSF) and recombinant human Interleukin 4 (rhIL-4). Virus-infected cell model was established by human bronchial epithelial cells (16HBE) infected with H1N1. After immunological cells and virus-infected cells were co-cultured, quercetin and oseltamivir were also added into the medium as a treatment intervention. Then the immunological cells were collected for Real Time PCR (RT-PCR) and Western blot to determine the expression levels of genes related to TLR7 pathway. Viral infection led to cell death and increased the gene expression levels of TLR7 signal pathway. Quercetin and oseltamivir increased cell viability and reduced the expression levels of TLR7 signal pathway.

[The immunomodulatory effects of sijunzi decoction and its disassembled prescription on D-galactose-induced aging mice].

OBJECTIVE: To observe the immunomodulatory effects of codonopsis, atractylodes macrocephala, tuceahoe, broiled licorice and sijunzi decoction on D-galactose-induced aging mice. METHODS: The models of aging mice were induced by D-galactose, the garlands and splenic lymphocyte transformation test (MTT) were used to determine the ability of erythrocytes immune and lymphocytes conversion; The content of maleic dialdehyde (MDA), activity of superoxide dismutase (SOD) and glutathione pemfidase (GSH-Px) in serum were detected. RESULTS: Sijunzi decoction and its disassembled prescription codonopsis could significantly increase the ability of T lymphocyte transformation (P<0.05); Atractylodes macrocephala and sijunzi decoction could significantly enhance C(3b) garlands ratio (P<0.05) and decrease IC garlands ratio (P<0.05) on D-galactose-induced aging mice. Sijunzi decoction significantly increased the activity of SOD and GSH-Px (P<0.01), and decreased the content of MDA in serum (P<0.05). CONCLUSION: Sijunzi decoction and its disassembled prescription codonopsis, atractylodes macrocephala can improve the immunomodulatory effects on D-galactose-induced aging mice; but tuceahoe and broiled licorice have no obvious effects.

[Effects of curcumin on TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice].

AIM: To study the effects of curcumin on TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice. METHODS: 75 mice were divided into five groups. After treated with curcumin 6 and 9 mice of each group were sacrificed on day 14 and 42 respectively to take their blood and lung tissue. The level of TNF-alpha and TGF-beta1 was observed by ELISA. RESULTS: The infection reaction of lung tissue and fibrosis in model group was obvious. Compared with sham operation group, TNF-alpha and TGF-beta1 in serum and lung tissue increased significantly(P<0.01), but decreased in different degrees after treated with curcumin(P<0.05). CONCLUSION: Curcumin can decrease the level of TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice and have the anti-fibrosis role by deregulating cytokine level.

[Studies on antiproliferative effect of flavones compounds isolated from Yao herb medicines].

OBJECTIVE: To detect the cytotoxicity and in vitro antiproliferative effects of the flavones compounds isolated from some Yao herbal medicines, and analyze the basic structure-activity relationship. METHODS: The cytotoxicity on normal cells and antiproliferative effect on tumor cells were tested by MTT reduction assay respectively. RESULTS: Among the 6 flavones, the Eriodictyol-7-O-a-D-glucoside, Naringenin-7-O-beta-D-glucoside, quercetin and quercetin-3-O-beta-D-glucoside showed very low cytotoxicity to the two normal cells, Vero and MC cells, while the naringenin was high toxic to both of them. The eriodictyol was no toxic to Vero Cell but could affect MC cell at low concentration. The naringenin exhibited a wide-spectrum antiproliferative effect on all of the 7 tested cancer cell lines especially on the MCF-7 with low IC50 about 50 microg/ml. Among these cancer cells, the MCF-7 and HepG2 were more sensitive to the flavones compounds than the others. Both of them were inhibited by eriodictyol, quercetin and naringenin even at low test concentration. Furthermore, the antiproliferative effects of these compounds were concentration-related. CONCLUSION: Some of flavones compounds isolated from some Yao herb medicines showed high antiproliferative effect on cancer cells with low cytotoxicity on normal cells.

[Clinical value of the detection of hepatitis C virus core antigen].

AIM: To explore the value of detecting hepatitis C virus core antigen in HCV infected diseases. METHODS: The HCV-RNA was tested by fluorescent quantitative polymerase chain reaction (FQ-PCR). The core antigens of HCV and anti-HCV were tested by enzyme-linked immunosorbent assay (ELISA). RESULTS: The positive rate of HCV-RNA in 191 patients was 71.2%, about 136 in 191. The positive rate of anti-HCV was 97.4%, about 186 in 191. The positive rate of HCV core antigen was 33.0%, about 63 in 191. After antiviral therapy for 2 patients,their HCV-RNA and anti-HCV were detected negative but their HCV core antigen was detected positive. In another patient, his anti-HCV was negative but his HCV core antigen was positive. CONCLUSION: As a supplemental test for anti-HCV examination the detection of HCV core antigen is of important clinical value in HCV infection diagnosis.

[Effects of Dengue virus infection on PGIS expression and PGI2 secretion of human vascular endothelial cells].

AIM: To elucidate the effects of Dengue virus on the expression and secretion of prostacyclin (PGI(2)) in endothelial cells. METHODS: Cultured human umbilical vein endothelial cells (HUVEC) were infected by Dengue virus II(DV(2)) for different duration. PGI(2) level in the supernatant was determined by radioimmune assay. Cytoplasmic RNA of the infected HUVEC was prepared using the Trizol method and was assayed for prostacyclin synthase (PGIS) by RT-PCR. RESULTS: PGIS expression as well as PGI(2) secretion of the DV(2) group were significantly increased (P<0.05) at 48 h, 72 h and 96 h post-infection compared to the control group. CONCLUSION: DV(2) could promote the expression of PGIS mRNA in HUVEC and increase the level of PGI(2), which may increase the vascular permeability. The dysfunction of vascular endothelial cell (EC) induced by DV may be related to the pathogenesis of Dengue haemorrhagic fever (DHF) and Dengue shock syndrome(DSS).

[Preventive and therapeutic effects of qiongyugao on hepatocellular carcinoma via inhibition of the expression of HBxAg in hepatic carcinoma cells].

AIM: To investigate the effects of qiongyugao on the expression of hepatitis B x antigen (HBxAg) in BALB/c-nu mice into which human hepatic carcinoma cells were transplanted, and to analyze its specific mechanism in prophylaxis and treatment of hepatocellular carcinoma. METHODS: A nude mouse model with the transplantation of human hepatic carcinoma cells was established to observe the preventive and therapeutic effects of qiongyugao on the body weight and tumor weight of the mice. The expression of HBxAg in tumor and liver tissue wsa detected by immunohistochemical studies. RESULTS: Compared with model control group, prophylaxis and treatment with qiongyugao increased the body weight, depressed the tumor weight and inhibited HBxAg expression. The same efficacy was showed in both qiongyugao prophylaxis group and cyclophosphamide treatment group. CONCLUSION: Qiongyugao can slow down the growth of tumor and inhibit the expression of HBxAg, which may be an essential mechanism in prophylaxis and treatment of hepatocellular carcinoma.

[Effect of IL-6 and TNF-alpha on Dengue virus infection of human dendritic cells].

AIM: To study the effect of IL-6 and TNF-alpha on Dengue virus (DV) infection of human dendritic cells (DCs). METHODS: Monocytes isolated from healthy human peripheral blood were incubated in medium with GM-CSF and IL-4 for 7-10 days, and then were collected and identified by transmission electron microscope, immunohistochemistry and lymphocytes stimulatory ability assay. DCs infected with DV type II (DV(2)) were incubated with IL-6, TNF-alpha at high, medium and low concentration. The supernatants were collected at 6 h, 24 h, 48 h, 72 h and 96 h. The virus titers were determined by plaque assay and the number of DCs at 48 h postinfection was mensurated by MTT. RESULTS: IL-6 at medium or low concentration increased DV(2) replication in DCs, whereas TNF-alpha at high and medium concentration inhibited DV(2) replication in DCs. Cytokines had no effect on the number of normal DCs. CONCLUSION: IL-6 and TNF-alpha may play an important role in the pathogenicity and immunity of Dengue virus.

[Expression of tissue factor induced by IL-6 in HUVEC].

OBJECTIVE: To investigate the effects of IL-6 at the expression of tissue factor (TF) in human vein endothelial cells(HUVECs). METHODS: HUVECs were incubated with IL-6 at the concentration of 0.5 ng/mL. Cell viability was measured by CCK-8 assay. The TF mRNA was detected by reverse transcript-polymerase chain reaction(RT-PCR) method. RESULTS: When HUVECs were exposed to IL-6 (0.5 ng/mL) within a period of 72 h, their viability did not decrease in comparison with the control; there was no statistical difference between the two groups. After the HUVECs were exposed to IL-6 (0.5 ng/mL) for 6 h, the TF mRNA level increased, and it reached the peak at 12 h; then it began to decline. The expression of TF mRNA induced by IL-6 was evidently detected from 6 h to 48 h. After the HUVECs were treated by IL-6 over 72 h, the expression of TF mRNA was no longer detected in HUVECs. CONCLUSION: IL-6 at the concentration of 0.5 ng/mL did not exert direct effect on cell viability. The increase of TF mRNA expression in HUVECs induced by IL-6 could play an important role in the modulation of blood coagulation disorder and in the mechanism related to coagulation system changes during