Programmed death-1 expression is associated with the disease status in hepatitis B virus infection

AIM: To define the potential role of programmed death-1/programmed death-ligand (PD-1/PD-L) pathway in different hepatitis B virus (HBV) infection disease status; we examined the expression of PD-1 on antigen specific CD8+ T cells in peripheral blood of patients with chronic hepatitis B (CHB) and acute exacerbation of hepatitis B (AEHB) infection. METHODS: The PD-1 level on CD8+ T lymphocytes and the number of HBV specifi c CD8+ T lymphocytes in patients and healthy controls (HCs) were analyzed by staining with pentameric peptide-human leukocyte antigen2 (HLA2) complexes combined with flow cytometry. Real-time quantitative polymerase chain reaction (PCR) was used to measure the serum HBV-DNA levels. RESULTS: The level of PD-1 expression on total CD8+ T cells in CHB patients (13.86% ± 3.38%) was significantly higher than that in AEHB patients (6.80%± 2.19%, P < 0.01) and healthy individuals (4.63% ± 1.23%, P < 0.01). Compared to AEHB patients (0.81% ± 0.73%), lower frequency of HBV-specific CD8+ T cells was detected in chronic hepatitis B patients (0.37% ± 0.43%, P < 0.05). There was an inverse correlation between the strength of HBV-specific CD8+ T-cell response and the level of PD-1 expression. Besides, there was a significant positive correlation between HBV viral load and the percentage of PD-1 expression on CD8+ T cells in CHB and AEHB subjects (R = 0.541, P < 0.01). However, PD-1 expression was not associated with disease flare-ups as indicated by alanine aminotransferase (ALT) levels (R = 0.066, P > 0.05). CONCLUSION: Our results confirm previous reports that HBV specific CD8+ T-cell response in the peripheral blood is more intense in patients with AEHB than in chronic hepatitis B with persistent viral infection. Moreover, there is a negative correlation between the level of PD-1 and the intensity of virus specific CD8+T cell response.

Stable knockdown of heparanase expression in gastric cancer cells in vitro

AIM:To develop short hairpin RNA(shRNA)against heparanase,and to determine its effects on heparanase expression and the malignant characteristics of gastric cancer cells. METHODS:Heparanase-specific shRNA was constructed and transferred into cultured the gastric cancer cell line SGC-7901.Stable subclonal cells were screened by G418 selection.Heparanase expression was measured by reverse transcriptase-polymerase chain reaction(RT-PCR),real-time quantitative PCR and Western blotting.Cell proliferation was detected by 2-(4,5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)colorimetry and colony formation assay. The in vitro invasiveness and metastasis of cancer cells were measured by cell adhesion assay,wound healingassay and matrigel invasion assay.The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells. RESULTS:Stable transfection of heparanase-specific shRNA,but not of scrambled shRNA and mock vector,resulted in reduced mRNA and protein levels of heparanase.The shRNA-mediated knockdown of heparanase did not affect the cellular proliferation of SGC-7901 cells.However,the in vitro invasiveness and metastasis of cancer cells were decreased after knockdown of heparanase.Moreover,transfection of heparanase-specific shRNA decreased the in vitro angiogenesis capabilities of SGC-7901 cells. CONCLUSION:Stable knockdown of heparanase can efficiently decrease the invasiveness,metastasis and angiogenesis of human gastric cancer cells.In contrast,stable knockdown of heparanase does not affect the cell proliferation.

Replication of clinical hepatitis B virus isolate and its application for selecting antiviral agents for chronic hepatitis B patients

AIM: To establish a cell model harboring replicative clinical hepatitis B virus (HBV) isolates and evaluate its application in individualized selection of anti-HBV agents for chronic hepatitis B (CHB) patients. METHODS: The full-length HBV genomic DNA from 8 CHB patients was amplified by polymerase chain reaction (PCR). All the patients were treated with lamivudine for at least seven months and finally became resistant to lamivudine. The amplified HBV DNA fragments were inserted into pHY106 vectors by Sap Ⅰ?digestion. The recombinant plasmids containing 1.1 copies of HBV genome were transiently transfected into Huh7 cell line, and the levels of HBsAg, HBeAg and intercellular HBV replicative intermediates were determined by ELISA and Southern blot analysis, respectively, with or without lamivudine and adefovir treatment. The antiviral treatment with adefovir was administered to the patients and analyzed in parallel. RESULTS: A total of 25 independent HBV isolateswere obtained from the sera of 8 patients, each patient had at least two isolates. One isolate from each individual was selected and subcloned into pHY106 vector, including 5 isolates with YVDD mutation and 3 isolates with YIDD mutation. All recombinant plasmids harboring HBV isolates were transfected into Huh7 cells. The results indicated that HBV genome carried in HBV replicons of clinical HBV isolates could effectively replicate and express in Huh7 cells. Adefovir, but not lamivudine, inhibited HBV replication both in vitro and in vivo, and in vitro inhibition was dose-dependent. CONCLUSION: The novel method described herein enables individualized selection of anti-HBV agents in clinic and is useful in future studies of antiviral therapy for CHB.

Construction and Characterization of a Hepatitis B Virus Replicon

建立复制细胞肝炎 B 病毒(HBV ) 当模特儿并且在抗病毒的药评估决定它的应用程序，我们构造了表情包含了 HBV 染色体的 1.3 个拷贝，并且在 Huh7 房间在短暂 transfection 以后测量了病毒的复制的水平的 plasmid。我们然后观察了抗病毒的药管理的效果。HBV (ayw ) 基因碎片的 1.3 褶层被 PCR 和限制 endonuclease 消化克隆进 pCR2.1。recombinant plasmid 是进 Huh7 房间， HBsAg， HBeAg 和 HBV 的短暂 transfected 在 Huh7 房间的上层清液的 DNA 被 ELISA 和即时 PCR 分别地测量；细胞内部的 HBV replicative 中介和细胞内部的 HBV 抄本被南部的污点和北污点分别地检测。adefovir 的抗病毒的效果，新奇 anti-HBV 核苷酸类似物，在这个细胞的模型系统被评估。结果显示 HBV replicon 的 recombinant plasmid 成功地被构造；在 plasmid pHBV1.3 带的 HBV 染色体能高效地复制并且被表示在哈 7 个房间， adefovir 能在这个细胞的模型，和抑制禁止 HBV 复制是剂量依赖者。结论是 HBV replicon，能在 hepatoma 房间高效地开始病毒的复制，可以是在 HBV 复制和抗病毒的药的学习的一个有用工具。关键词肝炎 B 病毒 - 传染 replicon - 表示向量 CLC 数字 R373 基础条款：国家自然科学基础(No.30271170， No.30170889 ) 。