Levels of peripheral blood routine, biochemical and coagulation parameters in patients with hemorrhagic fever with renal syndrome and their relationship with prognosis: an observational cohort study.

BACKGROUND: Hantaan virus (HTNV), Seoul virus (SEOV) and Puumala virus (PUUV) are major serotypes of the Hantavirus, which can cause hemorrhagic fever with renal syndrome (HFRS). The pathophysiology of HFRS in humans is complex and the determinants associated with mortality, especially the coagulation and fibrinolysis disorders, are still not been fully elucidated. Severe patients usually manifest multiple complications except for acute kidney injury (AKI). The aim of this study was to observe the levels of peripheral blood routine, biochemical and coagulation parameters during the early stage, so as to find independent risk factors closely related to the prognosis, which may provide theoretical basis for targeted treatment and evaluation. METHODS: A total of 395 HFRS patients from December 2015 to December 2018 were retrospectively enrolled. According to prognosis, they were divided into a survival group (n = 368) and a death group (n = 27). The peripheral blood routine, biochemical and coagulation parameters were compared between the two groups on admission. The relationship between the parameters mentioned above and prognosis was analyzed, and the dynamic changes of the coagulation and fibrinolysis parameters during the first week after admission were further observed. RESULTS: In addition to AKI, liver injury was also common among the enrolled patients. Patients in the death group manifested higher levels of white blood cell counts (WBC) on admission. 27.30% (107/392) of the patients enrolled presented with disseminated intravascular coagulation (DIC) on admission and DIC is more common in the death group; The death patients manifested longer prothrombin time (PT) and activated partial thromboplastin time (APTT), higher D-dimer and fibrinogen degradation product (FDP), and lower levels of platelets (PLT) and fibrinogen (Fib) compared with those of the survival patients. The proportion of D-dimer and FDP abnormalities are higher than PT, APTT and Fib. Prolonged PT, low level of Fib and elevated total bilirubin (TBIL) on admission were considered as independent risk factors for prognosis (death). CONCLUSIONS: Detection of PT, Fib and TBIL on admission is necessary, which might be benefit to early predicting prognosis. It is also important to pay attention to the dynamic coagulation disorders and hyperfibrinolysis during the early stage in the severe HFRS patients.

Study on expression of plasma sCD138 in patients with hemorrhagic fever with renal syndrome.

BACKGROUND: Until now, there is non-specific treatment, and exploring early and novel biomarkers to determine the disease severity and prognosis of hemorrhagic fever with renal syndrome (HFRS) would be of importance for clinician to take systematic and timely intervention. This study observed the expression of plasma sCD138, a soluble component shedding from the glycocalyx (GCX) to the circulating blood, and evaluated its predictive value on disease severity and prognosis of HFRS. METHODS: One hundred and seventy-six patients with HFRS who were treated at our center between January 2011 and December 2013 were randomly enrolled in this study. The patients were divided into a mild-type group, a moderate-type group, a severe-type group and a critical-type group according to the HFRS criteria for clinical classification. Thirty-five blood samples from healthy subjects were obtained as the controls. The concentrations of sCD138 were detected using enzyme linked immunosorbent assay (ELISA). The levels of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cells (WBC), platelets (PLT), glucose (GLU), blood urea nitrogen (BUN) and serum creatinine (Scr) in the samples were routinely tested. The levels of sCD138 among the different types were compared; the correlation among sCD138 and the laboratory parameters mentioned above were analyzed. The predictive effectiveness for prognosis of sCD138 was evaluated using the receiver operating characteristic (ROC) curve analysis. RESULTS: Except for the mild-type, the levels of sCD138 in the moderate-, severe- and critical-type patients during the acute stage were significantly higher than that of the convalescent stage and the control (P<0.05). With the aggravation of the disease, the levels of sCD138 during the acute stage had an increasing tendency, while demonstrated no significant difference among the moderate-, severe- and critical-type patients (P>0.05). sCD138 was negatively correlated with Fib, PLT and ALB, and was positively correlated with WBC and AST (P<0.05). sCD138 demonstrated predictive effectiveness for prognosis with the area under the curve (AUC) of 0.778 (P<0.001). CONCLUSION: Dynamic detection of plasma sCD138 might be benefit to evaluating the disease severity and prognosis of the patients with HFRS.

[Diagnostic value of diffusion-weighted magnetic resonance imaging for solid tumors affecting the base of tongue and glossopharynx].

PURPOSE: The objective of the present study was to evaluate the potential application value of diffusion-weighted magnetic resonance imaging (DW-MRI) to differentiate solid benign from malignant tumors affecting the base of tongue and glossopharynx. METHODS: Sixty-one patients who presented with solid tumors affecting the base of tongue and glossopharynx underwent conventional MRI and DW-MRI before pathologic verification. Based on pathologic findings, the tumors were classified into 4 groups: Group 1, solid benign tumor (n=10); Group 2, epithelial carcinoma (n=35); Group 3: non- epithelial malignant tumor (n=16); and Group 4: malignant tumor (n=51, a combination of Group 2 and 3). The mean apparent diffusion coefficients (ADCs) were computed from DW-MRI scans obtained with b factors of 0 and 1000 s/mm2. SAS 9.1 software package was used for Wilcoxon test. RESULTS: The mean ADCs were significantly different (P<0.05) between group 1 and the other 3 groups, and between group 2 and group 3, respectively. Among all kinds of pathological types of lesions, non-Hodgkin lymphoma had a lowest mean ADC value, and schwannoma had a highest mean ADC value. In addition, the mean ADCs among epithelial carcinoma subtypes were not significantly different(P>0.05). CONCLUSIONS: DW-MRI has differential diagnostic value of solid tumors affecting the base of tongue and glossopharynx, especially in distinguishing between benign solid tumors and malignant tumors, and between epithelial carcinomas and non-epithelial malignant tumors.

Early indicators of severity and construction of a risk model for prognosis based upon laboratory parameters in patients with hemorrhagic fever with renal syndrome.

BACKGROUND: The objective of this study was to explore the role of laboratory parameters as early indicators of severity and as effective predictors of prognosis in patients with hemorrhagic fever with renal syndrome (HFRS). METHODS: A total of 356 patients were enrolled in this study and were divided into mild, moderate, severe and critical types according to the clinical classification of HFRS. The levels of 12 routinely tested laboratory parameters during the acute stage among the four types were compared. The predictive values of the laboratory parameters for prognosis were analyzed, and a risk model for prognosis based upon the parameters was constructed. RESULTS: The levels of white blood counts (WBC), platelets (PLT), aspartate aminotransferase (AST), albumin (ALB), blood urea nitrogen (BUN), serum creatinine (Scr), prothrombin time (PT) and activated partial thromboplastin time (APTT) demonstrated significant differences among the four types (p<0.001); WBC, AST, PT and fibrinogen (Fib) were major independent risk factors for death; WBC, AST, PT and Fib used in combination were better for predicting prognosis than single parameters used alone (p<0.001). CONCLUSIONS: Some routinely tested laboratory parameters can be beneficial as early indicators of severity of HFRS. Using a combination of WBC, AST, PT and Fib to predict the outcome in patients with HFRS exhibited acceptable diagnostic capability.

Clinical characteristics and outcomes in critical patients with hemorrhagic fever with renal syndrome.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) has become an important public health concern because of the high incidence and mortality rates, and limited treatment and vaccination. Until now, clinical studies on characteristics and outcomes in critical patients with HFRS have been limited. The aim of this study was to observe the clinical characteristics and cumulative proportions surviving and explore the predictive effects and risk factors for prognosis. METHODS: A detailed retrospective analysis of clinical records for critical HFRS patients was conducted. The patients enrolled were treated in the centre for infectious diseases, Tangdu Hospital, between January 2008 and August 2012. The clinical characteristics between the survivors and non-survivors were compared by Student's t-test or Chi-square test. The risk clinical factors for prognosis were explored by logistic regression analysis. The predictive effects of prognosis in clinical and laboratory parameters were analyzed by receiver operating characteristic (ROC) curves. The cumulative proportions surviving at certain intervals in the critical patients were observed by Kaplan-Meier survival analysis. RESULTS: Of the 75 patients enrolled, the cumulative proportion surviving was 70.7% at the second week interval, with a 28-day mortality rate of 36.3%. The non-survivors tended to have higher frequencies of agitation, dyspnea, conjunctival hemorrhage, coma, cardiac failure, acute respiratory distress syndrome (ARDS) and encephalopathy (P < .05). ARDS, conjunctival hemorrhage and coma were risk factors for death in the critical patients with HFRS. The non-survivors were found to have lower serum creatinine (Scr) levels (P < .001) and higher incidences of prolonged prothrombin time (PT) (P = .006), activated partial thromboplastin time (APTT) (P = .003) and elevated white blood cells (WBC) levels (P = .005), and the laboratory parameters mentioned above reached statistical significance for predicting prognosis (P < .05). CONCLUSION: The high fatality in critical patients with HFRS underscores the importance of clinicians' alertness to the occurrence of potentially fatal complications and changes in biochemical status to ensure that timely and systematically supportive treatment can be initiated when necessary.

Role of Nogo­A in the regulation of hepatocellular carcinoma SMMC­7721 cell apoptosis.

Nogo-A has been identified as an inhibitor of neurite outgrowth specific to the central nervous system. However, little is known about the role of Nogo-A in hepatocellular carcinoma (HCC), the most common primary malignant tumor with a high mortality rate. This study aimed to investigate the role of endogenous Nogo-A in human liver cancer cells. Reverse transcription polymerase chain reaction was used to detect the expression of Nogo-A in four liver cancer cell lines. A lentivirus vector was then constructed to mediate RNA interference (RNAi) targeting of Nogo­A (LV­Nogo-A­siRNA) and was confirmed to successfully suppress the expression of the Nogo-A gene in SMMC-7721 cells. Furthermore, Nogo-A was observed to be highly expressed in liver cancer cell lines. RNAi of Nogo-A using the LV­Nogo-A­siRNA construct significantly decreased Nogo-A protein expression and specifically inhibited the growth of SMMC-7721 cells. This growth inhibitory effect may be attributed to an increase in G2/M phase arrest and apoptosis in SMMC-7721 cells containing Nogo-A­siRNA. The results of this study demonstrate that Nogo-A may represent a novel therapeutic target for the treatment of liver cancer, in addition to its potent roles in neural systems.

Development of a SYBR Green I based one-step real-time PCR assay for the detection of Hantaan virus.

Hantaan virus (HTNV), which belongs to the genus Hantavirus, causes hemorrhagic fever with renal syndrome (HFRS) mainly in China. The diagnosis of HFRS depends on clinical manifestations and serological tests. A SYBR Green I based one-step real-time PCR assay was established in this study to detect HTNV. The HTNV standard curves were generated by plotting mean cycle threshold (Ct) values versus 10-fold serial dilutions of a previous titrated HTNV stock over a wide range of concentrations (1×10(7) to 1PFU/ml). The minimum detection limit of the assay was 1PFU/ml, and it was 100-fold more sensitive than conventional RT-PCR. Melting curve analysis indicated that there were no primer-dimers and non-specific products in the assay. No cross-reaction was observed with Seoul virus (SEOV). The specificity of the asssay was also verified by nuleotide sequencing of the PCR products. Intra- and inter-assay variability data were analyzed to examine the reproducibility of the assay. HTNV viral loads in HFRS patients were also investigated with the assay. These results indicated that the one-step real-time PCR assay is useful for detecting HTNV and for monitoring the viral loads.

Quantification of Hantaan virus with a SYBR green I-based one-step qRT-PCR assay.

Hantaan virus (HTNV) is a major zoonotic pathogen that causes hemorrhagic fever with renal syndrome (HFRS) in Asia, especially in China. Shaanxi province, which is located in northwest of China, is one of the areas in China most severely afflicted with HFRS epidemics annually. This study aims to establish a quantitative RT-PCR (qRT-PCR) assay to detect HTNV both in cell culture and clinical serum samples. We established a SYBR Green I-based one-step qRT-PCR assay that targets the S segment of the HTNV genome for rapid detection and quantification. The HTNV cRNA standards were constructed by in vitro transcription, and the copy numbers of the HTNV cRNA were quantified. Standard curve was generated by determining the mean cycle threshold (Ct) values versus 10-fold serial dilutions of the HTNV cRNA over a range of 1 × 10(8) to 1 × 10(3) copies/µl. The standard curve had a reaction efficiency of 102.1%, a correlation coefficient (R(2)) of 0.998, and a slope of -3.273. The coefficient of variation (CV) of the intra- and inter-assays ranged from 0.68% to 3.00% and from 0.86% to 3.21%, respectively. The cycle intervals of the qRT-PCR assay between each dilution ranged from 2.9 to 3.8 cycles, and the lowest detection limit of the qRT-PCR assay was 10 copies/µl. The assay exhibited high specificity that was confirmed by melting curve analysis, and no cross reaction with the Seoul virus (SEOV) and other viruses (HBV, HCV and HIV) was observed. HTNV RNA was also detected in the 27 serum samples of clinical HFRS patients using the assay, and the HTNV RNA viral load ranged from 2.06 × 10(1) to 1.95 × 10(5) copies/µl. The SYBR Green I-based one-step qRT-PCR assay is a sensitive, specific, reproducible, and simple method for detecting and quantifying HTNV in cell culture and clinical samples.

[Evaluation of soft tissue lesions affecting the masticator space with dynamic contrast enhanced MRI].

OBJECTIVE: To determine the characteristics and diagnostic value of dynamic contrast enhanced MRI (DCE-MRI) in differentiating benign soft tissue lesions from malignant tumors affecting the masticator space (MS). METHODS: Prior to managements, conventional MRI and DCE-MRI were performed in 53 patients who suffered from primary or secondary soft tissue lesions affecting the MS. The time to peak (TTP), relative maximum enhancement (RME) and relative washout ratio (RWO) were separately calculated. RESULTS: Mean TTP of benign and malignant lesions were (130.3 ± 13.2) and (69.6 ± 6.9) s, respectively. Mean RWO of benign and malignant lesions were (29.7 ± 5.5)% and (8.7 ± 2.1)%, respectively. Malignant lesions had a significantly shorter TTP(P = 0.001) and lower RWO (P = 0.003) than benign lesions. When TTP was less than 92.2 s and RWO less than or equal to 16.0%, malignant tumors were considered. DCE-MRI had a sensitivity of 72.3%, specificity of 93.5%, accuracy of 84.9%, positive predictive value of 88.9%, and negative predictive value of 82.9%. CONCLUSIONS: As a non-invasive imaging technique, DCE-MRI is valuable to differentiate benign soft tissue lesions from malignant tumors affecting the MS.

Hantaan virus triggers TLR4-dependent innate immune responses.

The innate immune response induced by Hantavirus is responsible for endothelial cell dysfunction and viral pathogenicity. Recent studies demonstrate that TLR4 expression is upregulated and mediates the secretion of several cytokines in Hantaan virus (HTNV)-infected endothelial cells. To examine viral interactions with host endothelial cells and characterize the innate antiviral responses associated with Toll-like receptors, we selected TLR4 as the target molecule to investigate anti-hantavirus immunity. TLR4 mRNA-silenced EVC-304 (EVC-304 TLR4-) cells and EVC-304 cells were used to investigate signaling molecules downstream of TLR4. The expression of the adaptor protein TRIF was higher in HTNV-infected EVC-304 cells than in EVC-304 TLR4- cells. However, there was no apparent difference in the expression of MyD88 in either cell line. The transcription factors for NF-κB and IRF-3 were translocated from the cytoplasm into the nucleus in HTNV-infected EVC-304 cells, but not in HTNV-infected EVC-304 TLR4- cells. Our results demonstrate that TLR4 may play an important role in the antiviral immunity of the host against HTNV infection through an MyD88-independent signaling pathway.

Dysregulation of the ß3 integrin-VEGFR2 complex in Hantaan virus-directed hyperpermeability upon treatment with VEGF.

Hantaviruses infect human endothelial cells (ECs) and are known to cause vascular-permeability-based diseases, including hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The αvß3 integrins, which are highly expressed on the surface of ECs, serve as hantavirus receptors. Specifically, the ß3 integrin and vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) form a functional complex and interact with each other. Signaling through this complex causes cytoskeletal reorganization, which is one of the most important mechanisms underlying hyperpermeability. In this study, we show that VEGF dramatically enhances Hantaan virus (HTNV)-directed permeability and increases the reorganization of the cytoskeleton and the disruption of junctional organizations in an EC monolayer at 3 days postinfection. HTNV infection reduced the effect of VEGF on adhesion, migration, and the upregulation of ß3 expression, but the infection alone upregulated the expression of ß3 and VEGFR2. These results indicate that in addition to its role in blocking ß3 integrin activation as reported previously, HTNV blocks the function of the complex of VEGFR2 and ß3 integrin, and the dysfunction of the complex may contribute to cytoskeletal reorganization in an HTNV-directed hyperpermeability response to VEGF.

[Assessment of normal and abnormal tongue tissues with MR diffusion-weighted imaging].

PURPOSE: The aim of this study was to evaluate the MR-DWI findings of the normal and abnormal tongue tissues, and to determine the potential role of apparent diffusion coefficient (ADC) value obtained from different b values in the accurately diagnosing lesions arising from the tongue. METHODS: MR-DWI was performed in 15 healthy volunteers and 79 patients with tongue lesions, respectively. All the tongue lesions were pathologically proved (19 benign lesions and 60 malignant tumors). Two ADC values from b values (500 and 1000 s/mm²) in the 15 volunteers and 79 lesions were used for comparison. The diversities of ADC values between the normal and abnormal tongues, and the benign lesions and malignant tumors of tongues were statistically analyzed. The data was subjected to SPSS10.0 software package for t test. RESULTS: (1)There was significant difference between the volunteer's tongue and the abnormal tongues(P<0.01), and between the benign lesions and the malignant tumors of tongues (P<0.05). (2)The mean ADC value of the benign lesions of tongues was significantly higher than that of the surrounding tongue tissues and volunteer's tongues (P<0.05). (3)The mean ADC value of the malignant tumors of tongues was higher than that of the volunteer's tongues, but no difference was found between the malignant tumors and its surrounding tongue tissues. CONCLUSION: MR-DWI might be considered as a valuable imaging index for the discrimination of normal tongue from abnormal tongue.

[Evaluation of MR diffusion-weighted imaging (MR-DWI) between head and neck hemangioma and venous malformation in children].

PURPOSE: To analyze and evaluate the MR diffusion-weighted imaging (MR-DWI) features of head and neck hemangioma and venous malformation in children. METHODS: We retrospectively observed 10 head and neck hemangiomas and 40 head and neck venous malformations in children, which underwent both conventional MR imaging and MR-DWI. In the MR-DW images, the apparent diffusion coefficient(ADC) mean value was taken from b=500 s/mm² and 1000 s/mm², The data was analyzed using SPSS13.0 software package for t test. RESULTS: The mean ADC obtained from b value of 500 s/mm² was (1.227±0.324)x10⁻³mm²/s in hemangioma and (1.851±0.364)x10⁻³mm²/s in venous malformation, and from b value of 1000 s/mm² was (0.728±0.256)x10⁻³mm²/s in hemangioma and (1.200±0.228)x10⁻³mm²/s in vein malformation. There was significant difference between both lesions (P<0.01). CONCLUSION: There are different features in MR-DWI between head and neck hemangioma and venous malformation in children, which may be helpful for radiological differential diagnosis.

Calcineurin promotes proliferation, migration, and invasion of small cell lung cancer.

A novel role for calcineurin (Cn) has been reported recently regarding the oncogenic potential in pancreatic and colorectal cancer. The aim of this study was to investigate the putative causal role calcineurin could play in the development of lung cancer with bone metastases. We found that CnAalpha, an isoform of calcineurin, was significantly overexpressed in lung cancer tissues with bone metastasis as compared to tumors with non-bone metastases as investigated by RT-PCR. Strong nuclear staining of tumor cells was observed in small cell lung cancer tissues with bone metastasis. Conversely, cytoplasmic staining of tumor cells was observed in small cell lung cancer tissues with non-bone metastasis. Western blots of nuclear proteins from lung cancer tissues indicated that CnAalpha was highly expressed in lung cancer tissues with bone metastases, but not in those with non-bone metastases. In vitro, it was demonstrated that the CnAalpha gene obviously promoted cell proliferation and inhibited cell apotosis. The CnAalpha gene affected the cell cycle and promoted G1[Symbol: see text]S transition in SBC-3 cells. Transfection with the CnAalpha gene promoted cell migration and invasion. These results indicated that CnAalpha may affect the biological behavior of the human small cell lung cancer cell line SBC-3 in vitro and may be a candidate tumor promotor gene for developing bone metastases.

Circulating Toll-like receptor (TLR) 2, TLR4, and regulatory T cells in patients with chronic hepatitis C.

The mechanism of hepatitis C virus (HCV) involvement in innate immune responses and immune modulation has not been well characterized. In the present work, we studied Toll-like receptor (TLR) 2 and TLR4, which were recently recognized as the important components of innate immunity, as well as CD4+ CD25+ CD127low/- regulatory T cells (Tregs), which actively suppress pathological and physiological immune response during HCV infection. The study involved 31 chronic hepatitis C patients and 20 healthy controls. TLR2 and TLR4 expression in peripheral blood monocytes and the number of Tregs were examined by flow cytometric analysis. Overexpression of TLR2 and TLR4 was found in chronic hepatitis C patients as compared with controls. Furthermore, increased cytokine production, including that of beta-interferon, tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8, was observed in peripheral blood mononuclear cells from chronic hepatitis C patients after challenge with TLR2 and TLR4 agonists. The number of Tregs was significantly higher in chronic hepatitis C patients and the increased Tregs were associated with HCV genotype 1b. In vitro studies demonstrated that circulating Tregs suppress T-cell responses in chronic hepatitis C patients. Significant correlations were found between the viral load and Treg number and between TLR2 and TLR4 level in chronic hepatitis C patients. Taken together with other published data, these results suggest that TLR2, TLR4, and Tregs correlate closely with chronic HCV infection.

Overexpression of Toll-like receptor 2/4 on monocytes modulates the activities of CD4(+)CD25(+) regulatory T cells in chronic hepatitis B virus infection.

The significance of TLR expression and Tregs in HBV infection has not been clearly described. In this report, flow cytometry was performed to assess TLR2/4 expression on monocytes and circulating CD4(+)CD25(+)CD127(low/-) Tregs frequency of 16 acute hepatitis B (AHB), 42 chronic hepatitis B (CHB), 22 asymptomatic HBV carriers (AsC), and 20 normal controls (NC). We found that TLR2 and TLR4 were overexpressed on CD14(+) monocytes in HBV-infected patients as compared with NCs. Upregulation of TLR2 in NCs and TLR4 in CHBs was observed following HBeAg incubation. However, TLR2 and TLR4 expression decreased after HBcAg stimulation. The difference in the proportion of Tregs between NCs and CHBs was significant. Both Pam3Csk4 (TLR2 agonist)- and lipopolysaccharide (TLR4 agonist)-activated CD4(+)CD25(+) Tregs showed enhanced suppression function in CHBs. These results suggest that overexpression of TLR2 and TLR4 may modulate the suppressive function of Tregs, which contribute to the immunotolerance of chronic HBV infection.

Analysis of the immune response to Hantaan virus nucleocapsid protein C-terminal-specific CD8(+) T cells in patients with hemorrhagic fever with renal syndrome.

Hantaan virus (HTNV), the prototype member of the Hantavirus genus in the family Bunyaviridae, causes hemorrhagic fever with renal syndrome (HFRS), which is characterized by capillary leakage, hemorrhage, and renal injury, and is an important public health problem in China. Some kinds of immune cells, particularly CD8(+) T cells, are involved in the pathogenesis of Hantavirus infection. The nucleocapsid protein (NP) of the Hantavirus is the most conserved structural protein and the most abundant viral protein produced during infection. It is one of the important target antigens that induce the CD8(+) T-cell response. In this study, we examined the CD8(+) T-cell response to HTNV NP C-terminal polypeptides. We synthesized 23 overlapping C-terminal polypeptides and detected the antigen-specific CD8(+) T cell response in 15 patients with HFRS. The results demonstrated that there were NP-specific T-cell responses in bulk cultures of peripheral blood mononuclear cells (PBMCs) from 9 of 15 patients. The peptide 51 (aa 301-315: SPSSIWVFAGAPDRC), peptide 60 (aa 355-369: LRKKSSFYQSYLRRT), and peptide 70 (aa 415-429: DVKVKEISNQEPLKL) induced strong CD8(+) T-cell responses. Among them, peptide 70 induced CTL responses in donors 7, 9, and 11, and the strongest responses were seen in donor 11. Depletion of CD8(+) T cells from PBMCs completely abrogated the peptide-specific T-cell response, while depletion of CD4(+) T cells did not diminish the number of IFN-gamma spot-forming cells. These data suggest that infection with HTNV results in CTL responses to immunodominant regions on the NP.

Down-regulation of CXCR4 expression by SDF-KDEL in CD34(+) hematopoietic stem cells: An anti-human immunodeficiency virus strategy.

CXCR4 plays an essential role as the first discovered coreceptor for the entry of T cell tropic isolates of HIV-1. Blocking the surface expression of this receptor may be a potential strategy to prevent HIV-1 infection. A lentiviral vector, pLenti6/V5-S-K, expressing a SDF-KDEL fusion protein was constructed and a replication-incompetent lentiviral stock was produced. The lentiviral stock was transduced into CD34(+) hHSC and the transient expression of the recombinant protein, SDF-1, was assayed using indirect immunofluorescence. The surface expression of CXCR4 in CD34(+) hHSC pretreated with different amounts of recombinant lentiviral vectors was detected by flow cytometric analysis. A marked down-regulation of CXCR4 expression in the cells transduced with recombinant lentiviral vectors pLenti6/V5-S-K was observed by flow cytometry with PE-conjugated anti-human CXCR4 monoclonal antibodies which showed the percentages of the inhibition effects of CXCR4-SDF-1 mediated syncytium formation are presented by concentration. P24 antigen levels of cell culture supernatants were detected on the 4th, 7th, and 10th day, with 10(3) TCID50 HIV-1 infected CD34(+) hHSC to evaluate the inhibitory effect of pLenti6/V5-S-K transduction on HIV-1 infection. The cells transfected with pLenti6/V5-S-K had a significant reduction of HIV-1 DP27 infection compared to controls (P<0.05).

Inhibition of hepatitis C virus infection by interferon-gamma through downregulating claudin-1.

Hepatitis C virus (HCV) is a serious global health threat and current medical treatment options are limited. Interferon (IFN)-gamma is an important proinflammatory cytokine with antiviral activity. However, the mechanism of IFN-gamma in anti-HCV infection remains unclear. In this study, we investigated the role of IFN-gamma on HCV infection of polarized Caco-2 cells using cell culture-derived HCV (HCVcc). We found that downregulation of claudin-1 (CLDN1) induced by IFN-gamma resulted in disruption of barrier function as demonstrated by measurement of transepithelial electrical resistance and dextran permeability. Further, results from confocal microscopy and Western blot analysis showed that in addition to the reduction of CLDN1 expression, IFN-gamma treatment also led to significant changes in the distribution of CLDN1, CD81, and scavenger receptor class B type I. Moreover, infection assays revealed that IFN-gamma-treated cells showed decreased susceptibility to HCVcc infection. These results suggest a novel mechanism that IFN-gamma may inhibit HCV infection by regulating CLDN1 expression and distribution of HCV receptors.

Hantaan virus induces toll-like receptor 4 expression, leading to enhanced production of beta interferon, interleukin-6 and tumor necrosis factor-alpha.

Hantaan virus (HTNV) infects endothelial cells and is associated with increased vascular permeability during hemorrhagic fever with renal syndrome (HFRS). The pattern of increased vascular permeability is mediated by immune response. Therefore, it is necessary to characterize the mechanism of HTNV involvement in the host's innate immune. In this study, the expression of five toll-like receptors (TLRs) was analyzed in Endothelial vein cells (EVC-304) following HTNV infection in vitro. TLR4 showed an altered expression after HTNV infection. HTNV infection significantly increased IFN-beta, IL-6 and TNF-alpha secretion from EVC-304 cells, particularly after lipopolysaccharide stimulation. The increased IFN-beta, IL-6 and TNF-alpha production was mediated by TLR4 induction, since the introduction of the small interfering RNA against TLR4 specifically inhibited the HTNV-induced cytokine production. In conclusion, HTNV infection directly induces TLR4 expression and thereby enhanced production of IFN-beta, IL-6 and TNF-alpha, which may contribute to the host's innate immune response.