Computed Tomography-guided Cryoablation for Adrenal Pheochromocytoma: Safety and Clinical Effectiveness.

PURPOSE: To evaluate the safety and clinical effectiveness of computed tomography (CT)-guided cryoablation for adrenal pheochromocytoma (AP). MATERIALS AND METHODS: From July 2015 to October 2018, we observed 8 patients that underwent CT-guided cryoablation for AP. The blood pressure and pulse before treatment did not exceed 150/90 mm Hg and 90 times/min, respectively. Complete ablation rate, clinical success rate, and long-term outcomes were analyzed. RESULTS: A total of 8 patients with 8 APs were treated by CT-guided cryoablation. The mean duration of the procedure was 67.5±4.6 minutes. No patient achieved complete ablation, yet the clinical success rate was 100%. The mean metanephrine decreased from 61.7±11.1 to 2.0±1.1 nmol/L (P<0.001). Hypertensive crisis was found in 5 (67.5%) patients during the procedure. During a mean follow-up of 16.9±13.4 months, no patient experienced tumor progression. CONCLUSION: CT-guided cryoablation is an effective method for patients with AP.

Elevated interleukin-35 suppresses liver inflammation by regulation of T helper 17 cells in acute hepatitis B virus infection.

Interleukin (IL)-35 is a responsive anti-inflammatory cytokine implicated in different diseases processes. It has been reported that elevated IL-35 contributed to immunosuppression in chronic hepatitis by modulation of T helper 17 (Th17) and regulatory T cells. However, the role of IL-35 in acute hepatitis B (AHB) was still not completely elucidated. Thus, in the present study, we analyzed the expression and regulatory activity of IL-35 to Th17 cells and inflammatory response during acute hepatitis B virus (HBV) infection in both peripheral blood cells isolated from AHB patients and in hydrodynamic induced HBV-infected mouse model. Plasma IL-35 level and circulating HBV peptides-induced Th17 frequency was significantly elevated in AHB patients, and IL-35 expression negatively correlated with liver inflammation. In vitro IL-35 stimulation to CD4+ T cells purified from AHB patients down-regulated HBV peptides-induced Th17-phenotype, which presented as reduced IL-17 and IL-22 production. In vivo IL-35 administration dampened liver inflammation in HBV plasmid injected mice, however, did not affect HBV antigens production. This process was accompanied by suppression of natural killer cells and down-regulation of HBV peptides-induced Th17 cells in the liver, but did not affect total intrahepatic lymphocytes and other cell subsets numbers or chemokines expression in the liver. In conclusion, the current data indicated that IL-35 might be a novel mediator associated with hepatocytes damage and liver inflammation by regulating HBV peptides-induced Th17 cells during acute HBV infection. The potential anti-inflammatory property of IL-35 might be pivotal for developing new therapeutic approaches for hepatitis B.

Alcohol consumption analysis among patients with liver disease in China.

BACKGROUND: Alcohol consumption has been observed to be a contributing factor in liver damage. However, very few studies have tried to decipher the correlation between patients with liver disease and alcohol consumption. Therefore, this study was planned to determine the prevalence of alcohol consumption among patients with liver disease, and to evaluate the risk factors, liver diseases, and chronic medical conditions associated with alcohol drinking. METHODS: A cross-sectional study was conducted among patients with liver disease in 30 provinces, autonomous regions, and municipalities across China. All participants answered the questionnaire, which led to the calculation of Alcohol Use Disorders Inventory Test (AUDIT) score for each patient. Based on this score, low-risk drinkers, hazardous drinkers, and harmful drinkers were defined as having AUDIT score of <8, between 8 and 15, and ≥16, respectively. RESULTS: A total of 1489 participants completed the questionnaire. Based on this information, 900 (60.44%) participants were classified as alcohol drinkers. Among these, 8.66% were ex-drinkers, 22.10% were low-risk drinkers, 17.13% were hazardous drinkers, and 12.56% were harmful drinkers. Further investigation of the association between alcohol consumption and other baseline characteristics of patients with liver disease revealed that usually men <40 years old, participants having higher family annual income, having college degree or higher education, living alone, having higher body mass index (BMI), current smokers, and ex-smokers had significant association with higher risk of alcohol consumption. In addition, among the 18.07% of the participants with cirrhosis, it was observed that risk of cirrhosis increased with higher alcohol consumption. Furthermore, harmful drinkers showed greater odds of hypertension and heart diseases, while hazardous drinkers and harmful drinkers, both had greater odds of hyperlipidemia. CONCLUSIONS: Overall our analyses indicated that among the patients with liver disease in China, there was high rate of alcohol consumption and dependence. Alcohol consumption usually associated with men <40 years old, higher family income, education level, living alone, high BMI, and smoking. Increased alcohol consumption not only increased the risk of cirrhosis, but also enhanced the risk of hypertension, heart diseases, and hyperlipidemia.

Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection.

The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B.

Will Sofosbuvir/Ledipasvir (Harvoni) Be Cost-Effective and Affordable for Chinese Patients Infected with Hepatitis C Virus? An Economic Analysis Using Real-World Data.

BACKGROUND: Little is known on the cost-effectiveness of novel regimens for hepatitis C virus (HCV) compared with standard-of-care with pegylated interferon (pegIFN) and ribavirin (RBV) therapy in developing countries. We evaluated cost-effectiveness of sofosbuvir/ledipasvir for 12 weeks compared with a 48-week pegIFN-RBV regimen in Chinese patients with genotype 1b HCV infection by economic regions. METHODS: A decision analytic Markov model was developed to estimate quality-adjusted-life-years, lifetime cost of HCV infection and incremental cost-effectiveness ratios (ICERs). SVR rates and direct medical costs were obtained from real-world data. Parameter uncertainty was assessed by one-way and probabilistic sensitivity analyses. Threshold analysis was conducted to estimate the price which can make the regimen cost-effective and affordable. RESULTS: Sofosbuvir/ledipasvir was cost-effective in treatment-experienced patients with an ICER of US$21,612. It varied by economic regions. The probability of cost-effectiveness was 18% and 47% for treatment-naive and experienced patients, and it ranged from 15% in treatment-naïve patients in Central-China to 64% in treatment-experienced patients in Eastern-China. The price of 12-week sofosbuvir/ledipasvir treatment needs to be reduced by at least 81% to US$18,185 to make the regimen cost-effective in all patients at WTP of one time GDP per capita. The price has to be US$105 to make the regimen affordable in average patients in China. CONCLUSION: Sofosbuvir/ledipasvir regimen is not cost-effective in most Chinese patients with genotype 1b HCV infection. The results vary by economic regions. Drug price of sofosbuvir/ledipasvir needs to be substantially reduced when entering the market in China to ensure the widest accessibility.

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.

Telbivudine plus adefovir therapy for chronic hepatitis B patients with virological breakthrough or genotypic resistance to telbivudine.

BACKGROUND/AIM: There is very limited experience in the management of telbivudine (LdT)-associated virological breakthrough (VBT) and resistance in the treatment of chronic hepatitis B (CHB) patients, and the guideline recommendations are primitively based on the general principles of rescue therapy to nucleos(t)ide analog resistance. The aim of this study is to determine the effect of the addition of adefovir (ADV) in hepatitis B e antigen (HBeAg)-positive CHB patients with VBT or resistance to LdT. METHODS: Thirty-seven CHB patients with confirmed VBT and 31 patients with genotypic resistance to LdT were enrolled and thereafter treated with a combination of LdT and ADV for 12 months. RESULTS: Combination therapy was safe and the majority of patients tolerated the therapy. LdT+ADV led to rapid decreases in viral loads, and viral replications were persistently suppressed, with 2.17 (VBT) and 2.31 (resistance) log(10) copies/ml reductions 12 months after rescue therapy, respectively. The rates corresponding to virological and biochemical responses were similar between the two groups at the end of observations (70.3 vs. 74.2% for virological response, P=0.720; 64.0 vs. 65.5% for biochemical response, P=0.907). The cumulative rates of serological responses were higher in patients with VBT than in those with resistance (35.1 vs. 9.67% for HBeAg loss, P=0.014; 10.8 vs. 3.23% for HBeAg/anti-HBe seroconversion, P=0.233). CONCLUSION: LdT and ADV combination therapy led to significant decreases in serum hepatitis B virus DNA levels and normalization of alanine aminotransferase levels in patients with VBT or genotypic resistance to LdT. This rescue strategy was also associated with a higher rate of HBeAg serological outcomes in patients with confirmed LdT-related VBT.

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.

Inhibition of viral replication downregulates CD4(+)CD25(high) regulatory T cells and programmed death-ligand 1 in chronic hepatitis B.

Chronic hepatitis B is characterized by an impaired immune response to hepatitis B virus (HBV). Telbivudine treatment has significantly improved the clinical outcome of chronic HBV infection. However, the underlying mechanism behind the antiviral response of patients treated with nucleoside analogs remains unclear. To gather more evidence about the mechanism responsible for the weak immune response, in this study we analyzed the effects on HBV viral load of treatment with the nucleoside analogue telbivudine and the percentage of Tregs, programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) expression, and related cytokine production. Peripheral blood mononuclear cells (PBMCs) and serum of 28 patients with chronic hepatitis B were collected at baseline, and 3 mo and 6 mo after therapy was begun. In parallel with the decline in viral load and serum ALT normalization, we found a decline in circulating CD4(+)CD25(high) Tregs, PD-L1 on CD4(+) T cells, and IL-9 production. The expression of PD-1 on CD4(+) T cells and the production of IFN-γ did not increase during therapy. Our findings suggest that the antiviral effect of the nucleoside analogs may be attributable not only to their direct effect on virus suppression, but also to their immunoregulatory capabilities.

Pathogens of spontaneous bacterial peritonitis change in northern China.

OBJECTIVE: To determine the identity of microorganisms isolated from patients diagnosed with spontaneous bacterial peritonitis (SBP). METHODS: We reviewed cases diagnosed with SBP over a 14-year period. The medical records of 780 SBP-diagnosed patients with decompensated cirrhosis and ascites admitted to Tangdu Hospital, Xian, Shaanxi Province, China were retrospectively reviewed between January 1996 and December 2009. The patients were placed into 2 groups, and the clinical data were compared between the 2 groups. Ascitic fluid was collected from these patients and cultured for bacteria using the MicroScan WalkAway 40 system. RESULTS: There was a significant difference in the ratio of pathogens between group A (48 patients, from January 1996 to December 2002) and group B (50 patients, from January 2003 to December 2009) (χ²=9.630, p=0.002). The SBP patients with gram-positive bacteria needed significantly more antibiotics within 30 days compared to those with gram-negative bacteria (χ²=12.285, p=0.000). CONCLUSION: In recent years, the types of isolated pathogens have significantly changed in northern China. Such changes have also been observed in other countries and have been attributed to long-term antibiotic therapy and invasive procedures. Changes in the epidemiology of pathogens that cause SBP must be monitored for optimal treatment.

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.

Circulating CD4+CD25high regulatory T cells and expression of PD-1 and BTLA on CD4+ T cells in patients with chronic hepatitis B virus infection.

The roles of regulatory T cells (Tregs) and PD-1 in hepatitis B have not been clearly described. Also, the role of B and T lymphocyte attenuator (BTLA), which serves as a negative regulator of T-cell activation, is still unknown in hepatitis B. In this study, we analyzed the frequency of circulating CD4(+)CD25(high) Tregs in patients with chronic hepatitis B (CHB), and subsequently investigated expression of PD-1 and BTLA on CD4(+) T cells, as well as their relationships with the clinical index of CHB patients. A total of 39 CHB patients and 19 healthy persons as controls were enrolled in the study. We found that the frequency of CD4(+)CD25(high) Tregs and PD-1 expression on CD4(+) T cells was significantly increased in CHB patients compared with normal controls. However, BTLA expression on CD4(+) T cells showed no significant difference between the two groups. The frequency of Tregs was significantly higher in patients with HBV DNA titers >or=10(8) than in those with HBV DNA titers <10(8). Circulating CD4(+)CD25(high) Treg frequency and PD-1 expression on CD4(+) T cells correlated positively with serum HBV DNA load in CHB patients. Our findings suggest that the increased frequency of CD4(+)CD25(high) Tregs and PD-1 expression on CD4(+) T lymphocytes may inhibit the cellular immune response against HBV and affect viral clearance, leading to the persistence of chronic HBV 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.

[Application of Epstein-Barr virus-transformed B lymphoblastic cells in identification of CTL epitopes specific for Hantaan virus].

AIM: To establish Epstein-Barr virus (EBV)-transformed B lymphoblastic cell lines (B-LCL) to present peptides as antigen-presenting cells (APC) and stimulate short-cultured T cells secreting IFN-gamma, by which the T cell epitopes are identified. METHODS: PBMCs from patients with hemorrhagic fever with renal syndrome (HFRS) were transformed using EBV from supernatant of B95-8 cells. ELISPOT assay was then employed to evaluate the IFN-gamma production of short-cultured G9L-specific CD8(+) T cells stimulated with peptide-pulsed autologous B-LCL cells. RESULTS: B-LCL pulsed with G9L or G9L-nested V15R can stimulate G9L-specific CD8(+) T cells producing IFN-gamma, but not B-LCL pulsed with non-homologous I15P. CONCLUSION: B-LCL can efficiently and specifically present peptides to peptide-specific T cells as non-professional APC.

[Study on the mechanism of HLA-I-expressing regulation caused by the core region mutation of HBV adr subtype].

OBJECTIVE: To study the influence and mechanism of HBV core region mutation on HLA-I expression. METHODS: Eukaryotic expression vectors of HBV core region mutations L97, G87 and V60 were constructed and transfected into HepG2 cells. Then the expressions of HLA-I were detected by RT-PCR and Western blot. The mRNA of antigen-presentation-associated genes, including LMP2, TAP1 and tapasin, were measured using RT-PCR. RESULTS: Different levels of HBsAg in the supernatants of transfected cells were detected by ELISA. The HBsAg of the mutated groups was markedly higher than that of the wild ones. All the transfected cells expressed HLA-I molecules, especially the L97 group. It was also found that the mRNA of TAP1 gene was up-regulated, while the mRNA of LMP and tapasin genes had no changes. CONCLUSION: The core region mutation of HBV can lower the expression of HBsAg; mutated groups and wild ones both can increase the expression of HLA-I molecules. The up-regulation of TAP1 gene expression might be the cause of these changes.