BACKGROUND & AIMS: :The present review gives an updated overview of transfusion transmitted virus (TTV), a novel agent, in relation to its molecular characteristics, epidemiological features, modes of transmission, tissue tropism, pathogenesis, role in various diseases and its eradication from the body. TTV, a DNA virus, is a single stranded, non-enveloped, 3.8 kb long DNA virus with a small and covalently closed circular genome comprising 3852 bases. It was tentatively designated Circinoviridae virus. TTV genome sequence is heterogeneous and reveals the existence of six different genotypes and several subtypes. TTV has been reported to transmit not only via parenteral routes, but also via alternate routes. This virus has been detected in different non-human primates as well. At present, TTV is detected by polymerase chain reaction (PCR) with no other available diagnostic assays. It shows its presence globally and was detected in high percent populations of healthy persons as well as in various disease groups. Initially it was supposed to have strong association with liver disease; however, there is little evidence to show its liver tropism and contribution in causing liver diseases. It shows high prevalence in hemodialysis patients, pointing towards its significance in renal diseases. In addition, TTV is associated with several infectious and non-infectious diseases. Though, its exact pathogenesis is not yet clear, TTV virus possibly resides and multiplies in bone marrow cells and peripheral blood mononuclear cells (PBMCs). Recently, attempts have been made to eradicate this virus with interferon treatment. More information is still needed to extricate various mysteries related to TTV.

背景与目标： : 本综述提供了有关输血传播病毒 (TTV) 的最新概述，该病毒是一种新型药物，涉及其分子特征，流行病学特征，传播方式，组织嗜性，发病机理，在各种疾病中的作用及其从体内根除。TTV是一种DNA病毒，是一种单链、无包膜、3.8 kb长的DNA病毒，具有包含3852碱基的小且共价闭合的环状基因组。暂定为Circinoviridae病毒。TTV基因组序列是异质的，揭示了六种不同基因型和几种亚型的存在。据报道，TTV不仅通过肠胃外途径传输，而且还通过替代途径传输。这种病毒也在不同的非人类灵长类动物中被检测到。目前，TTV是通过聚合酶链反应 (PCR) 检测的，没有其他可用的诊断方法。它显示了其在全球的存在，并在健康人群的高百分比人群以及各种疾病组中被检测到。最初，它应该与肝脏疾病有很强的联系; 但是，几乎没有证据表明其肝向性和在引起肝脏疾病中的贡献。它在血液透析患者中显示出很高的患病率，表明其在肾脏疾病中的重要性。此外，TTV还与几种传染病和非传染病有关。尽管TTV病毒的确切发病机制尚不清楚，但可能在骨髓细胞和外周血单个核细胞 (pbmc) 中存在并繁殖。最近，人们试图用干扰素治疗根除这种病毒。仍然需要更多的信息来解开与台视有关的各种谜团。

BACKGROUND & AIMS: :A panel of monoclonal antibodies which react with empty non-infectious type 3 poliovirus particles (C antigen) but not infectious virus (D antigen) were characterized for their reactivity with C antigen particles derived from neutralization-resistant virus strains which had single amino acid substitutions at each of the antigenic sites. Antibodies were identified which failed to bind to variant viruses with modifications at each of antigenic sites 2b, 3b and 4 indicating that the same amino acid sequences involved in the neutralization of infectious virus are also present on the surface of non-infectious particles but in different configurations.

背景与目标： : 一组与空的非感染性3型脊髓灰质炎病毒颗粒 (C抗原) 反应但不与感染性病毒 (D抗原) 反应的单克隆抗体的特征在于它们与源自中和抗性病毒株的C抗原颗粒的反应性在每个抗原位点具有单个氨基酸取代。鉴定出的抗体未能与变异病毒结合，并在每个抗原位点2b，3b和4处进行了修饰，这表明参与中和传染性病毒的相同氨基酸序列也存在于非感染性颗粒的表面上，但处于不同的构型。

BACKGROUND & AIMS: :Outside the nasopharynx, undifferentiated carcinomas occur only rarely at other head and neck locations. Although the association between undifferentiated nasopharyngeal carcinoma and Epstein-Barr virus (EBV) is consistent, there is conflicting evidence as to the association of EBV with undifferentiated carcinomas outside the nasopharynx. Here, we report on a case of undifferentiated carcinoma of the tongue base. A 71-year-old male, who had been treated with irradiation for primary unknown right neck metastatic EBV-positive undifferentiated carcinoma 9 years previously, was referred to our clinic with masses at the tongue base and right neck. The lesion at the tongue base was revealed to be an EBV-positive undifferentiated carcinoma. He was treated with resection of tongue base tumor and bilateral-neck dissection, and the defect at the tongue base was reconstructed with a free rectus abdominis myocutaneous flap. Re-irradiation was added post-operatively because of a positive surgical margin at the tongue base. The patient is presently alive without recurrence or distant metastasis 20 months after treatment. Although it is unclear whether our case is recurrent or newly developed EBV-latently infected undifferentiated carcinoma, we propose that EBV-associated tumors should be carefully observed after treatment at least for more than 10 years.

背景与目标： : 在鼻咽部以外，未分化癌仅在其他头颈部部位很少发生。尽管未分化鼻咽癌与爱泼斯坦-巴尔病毒 (EBV) 之间的关联是一致的，但关于EBV与鼻咽部以外未分化癌的关联的证据却相互矛盾。在这里，我们报告了一例未分化的舌根癌。一名71岁的男性，9年前曾接受过原发性未知的右颈转移性EBV阳性未分化癌的放射治疗，被转诊到我们的诊所，舌根和右颈有肿块。舌根病变被发现是EBV阳性未分化癌。他接受了舌根肿瘤切除术和双侧颈淋巴结清扫术，并用游离的腹直肌肌皮瓣重建了舌根缺损。由于舌根的手术切缘阳性，术后增加了再照射。治疗后20个月，患者目前还活着，没有复发或远处转移。尽管目前尚不清楚我们的病例是复发还是新开发的EBV潜伏感染的未分化癌，但我们建议在治疗至少10年以上后应仔细观察EBV相关肿瘤。

BACKGROUND & AIMS: :In the first step of retroviral integration, integrase cleaves the linear viral DNA within its long terminal repeat (LTR) immediately 3' to the CA dinucleotide step, resulting in a reactive 3' OH on one strand and a 5' two base overhang on the complementary strand. In order to investigate the structural properties of the 3' end processing site within the Moloney murine leukemia virus (MMLV) LTR d(TCTTTCATT), a host-guest crystallographic method was employed to determine the structures of four self-complementary 16 bp oligonucleotides including LTR sequences (underlined), d(TTTCATTGCAATGAAA), d(CTTTCATTAATGAAAG), d(TCTTTCATATGAAAGA) and d(CACAATGATCATTGTG), the guests, complexed with the N-terminal fragment of MMLV reverse transcriptase, the host. The structures of the LTR-containing oligonucleotides were compared to those of non-LTR oligonucleotides crystallized in the same lattice. Properties unique to the CA dinucleotide step within the LTR sequence, independent of its position from the end of the duplex, include a positive roll angle and negative slide value. This propensity for the CA dinucleotide step within the MMLV LTR sequence to adopt only positive roll angles is likely influenced by the more rigid, invariable 3' and 5' flanking TT dinucleotide steps and may be important for specific recognition and/or cleavage by the MMLV integrase.

背景与目标： : 在逆转录病毒整合的第一步中，整合酶将其长末端重复序列 (LTR) 中的线性病毒DNA立即切割为CA二核苷酸步骤3'，从而在一条链上产生反应性3'oh，在互补链上产生5' 两个碱基。为了研究莫洛尼鼠白血病病毒 (MMLV) LTR d (tcttttcatt) 中3' 末端处理位点的结构特性，采用宿主-客体晶体学方法确定了四个自互补的16 bp寡核苷酸的结构，包括LTR序列 (下划线)，来宾d (tttcatgcaatgaaa)，d(CTTTCATTAATGAAAG)，d (tcttcatatgaaaga) 和d (cacacatgatcatgtg) 与宿主MMLV逆转录酶的N末端片段复合。将含LTR的寡核苷酸的结构与在同一晶格中结晶的非LTR寡核苷酸的结构进行了比较。LTR序列中CA二核苷酸步骤所特有的性质，与其从双链体末端的位置无关，包括正侧倾角和负载玻片值。MMLV LTR序列中CA二核苷酸步骤仅采用正滚角的这种倾向可能受到更刚性，不变的3' 和5' 侧翼TT二核苷酸步骤的影响，并且对于特异性识别和/或切割可能很重要MMLV整合酶。

BACKGROUND & AIMS: :Human immunodeficiency virus (HIV) binds to cells via an interaction between CD4 and the virus envelope glycoprotein, gp120. Previous studies have localized the high affinity binding site for gp120 to the first domain of CD4, and monoclonal antibodies (mAbs) reactive with this region compete with gp120 binding and thereby block virus infectivity and syncytium formation. Despite a detailed understanding of the binding of gp120 to CD4, little is known of subsequent events leading to membrane fusion and virus entry. We describe two new mAbs reactive with the third domain of CD4 that inhibit steps subsequent to virus binding critical for HIV infectivity and cell fusion. Binding of recombinant gp120 or virus to CD4 is not inhibited by these antibodies, whereas infection and syncytium formation by a number of HIV isolates are blocked. These findings demonstrate that in addition to virus binding, CD4 may have an active role in membrane fusion.

背景与目标： : 人类免疫缺陷病毒 (HIV) 通过CD4与病毒包膜糖蛋白gp120之间的相互作用与细胞结合。先前的研究已将gp120的高亲和力结合位点定位于CD4的第一个结构域，与该区域反应性的单克隆抗体 (mab) 与gp120的结合竞争，从而阻止病毒的感染性和合胞体的形成。尽管对gp120与CD4的结合有详细的了解，但对导致膜融合和病毒进入的后续事件知之甚少。我们描述了两种与CD4的第三结构域反应的新mab，它们抑制了对HIV感染性和细胞融合至关重要的病毒结合之后的步骤。重组gp120或病毒与CD4的结合不受这些抗体的抑制，而许多HIV分离株的感染和合胞体形成被阻断。这些发现表明，除了病毒结合外，CD4可能在膜融合中起积极作用。

BACKGROUND & AIMS: :The oncoprotein LMP1 mimics an activated CD40 receptor, yet it is not known whether constitutive CD40 signaling, like LMP1, is sufficient to transform cells. Here we demonstrate that constitutive activation of the CD40 pathway by a chimeric LMP1CD40 molecule resembles the transforming function of LMP1 in inducing loss of contact inhibition and anchorage independent growth of Rat1 fibroblasts. Rat1 transformation correlates with the expression level of LMP1CD40 and depends on its ability to oligomerize. Our data provide direct evidence for the oncogenic potential of the CD40 signaling pathway, which is also established as a model-mechanism for LMP1-induced transformation.

背景与目标： : 癌蛋白LMP1模仿活化的CD40受体，但尚不清楚组成型CD40信号传导 (如LMP1) 是否足以转化细胞。在这里，我们证明了嵌合LMP1CD40分子对CD40途径的组成型激活类似于LMP1在诱导Rat1成纤维细胞的接触抑制丧失和锚定独立生长方面的转化功能。Rat1转化与LMP1CD40的表达水平相关，并取决于其寡聚能力。我们的数据为CD40信号通路的致癌潜力提供了直接证据，CD40信号通路也被确立为LMP1-induced转化的模型机制。

BACKGROUND & AIMS: Mayaro virus (alphavirus) infection of Aedes albopictus cells results in inhibition of cell protein synthesis and viral proteins are preferably synthesized. When infected cells are heat shocked, however, there is also an inhibition of viral protein synthesis, and there is preferential synthesis of heat shock proteins. Based on these observations, the distribution of Mayaro viral RNA in polysomes and the association of p34 (capsid protein) with ribosomal fractions of the cells under such conditions have been analyzed. During infection, the viral RNA is mainly observed in light polysomes (60% of total viral RNA in the cell) and also in heavy polysomes (13%). However, when infected cells are heat-shocked, the viral RNA is strongly mobilized from heavy polysomes to the light polysomes fraction and an enrichment in the unbound fraction can be noticed. The amount of p34 associated with the ribosomal fraction was also shown to be decreased in the heat shocked cells. These data lead to the suggestion that two mechanisms could be involved in the inhibition of Mayaro virus protein synthesis in response to heat shock(1) mobilization of Mayaro virus RNA from heavy to light polysomes; (2) a decrease in the amount of the p34 within the ribosomal fraction.

背景与目标： 白纹伊蚊细胞的Mayaro病毒 (α 病毒) 感染导致细胞蛋白合成的抑制，优选合成病毒蛋白。然而，当受感染的细胞被热休克时，病毒蛋白的合成也受到抑制，并且热休克蛋白的优先合成。基于这些观察结果，已经分析了在这种条件下，多核糖体中Mayaro病毒RNA的分布以及p34 (衣壳蛋白) 与细胞核糖体部分的关联。在感染期间，病毒RNA主要在轻多核糖体 (60% 细胞中总病毒RNA) 和重多核糖体 (13%) 中观察到。但是，当受感染的细胞受到热冲击时，病毒RNA会从重多核糖体强烈动员到轻多核糖体部分，并且可以注意到未结合部分的富集。在热休克细胞中，与核糖体级分相关的p34的量也显示出减少。这些数据表明，两种机制可能参与抑制马亚罗病毒蛋白合成，以响应热休克 (1) 马亚罗病毒RNA从重到轻多核糖体的动员; (2) 核糖体部分中p34的含量减少。

BACKGROUND & AIMS: OBJECTIVE:The purpose of this study was to use serial thin-section CT scans to assess the incidence of respiratory viral infection and lung abnormalities in a large patient population at high risk of pulmonary complications. MATERIALS AND METHODS:The study population consisted of 26 recipients of hematopoietic stem cell transplants who had proven respiratory viral pneumonia. In all cases, thin-section CT scans were obtained before fiberoptic bronchoscopy and bronchoalveolar lavage. The study included only patients in whom bronchoalveolar lavage fluid showed no evidence of organisms other than respiratory viruses. The CT scans were assessed for the presence, extent, and anatomic distribution of ground-glass attenuation, air-space consolidation, nodules, centrilobular branching structures (tree-in-bud), thickening of the bronchovascular bundles, and pleural effusion. RESULTS:Areas of ground-glass attenuation were identified in 24 (92%) of 26 patients and were the only finding in eight patients. Multiple nodules, seen in 17 (65%) of 26 patients, measured 3-10 mm in diameter or were larger than 10 mm. The nodules had a centrilobular or random distribution. A tree-in-bud appearance was seen in six of the patients with centrilobular nodules. This pattern had a bilateral distribution and involved mainly the lower lung zones. CT revealed thickening of the bronchovascular bundles in 16 (61%) of the patients. Thickening was bilateral in 14 and unilateral in two patients. Bronchial wall thickening involved the lower lobes in six patients and had a patchy random distribution in the remaining nine patients. Air-space consolidation was present in nine (35%) of the cases. It had a lobular or subsegmental distribution in eight of the patients and a segmental distribution in one patient. Areas of consolidation were randomly distributed throughout the lungs in all cases. Less common findings included bilateral pleural effusion and bronchial dilatation. CONCLUSION:Respiratory viral infection is common among adult recipients of hematopoietic stem cell transplants, occurring over a wide time span after transplantation. The presence of respiratory viral infection must be considered in any patient with new respiratory symptoms, fever, or findings at CT such as extensive or patchy areas of ground-glass opacities or a mixture of patterns, most commonly ground-glass attenuation, thickening of the bronchial walls, and multiple small nodules.

背景与目标：

BACKGROUND & AIMS: :Synthetic transcripts of tomato black ring virus satellite RNA (TBRV satRNA), isolate L, were prepared from cDNA cloned in the Bluescribe transcription vector. Transcripts with 49 (T49L) or two (T2GL) extra nucleotides at their 5' ends and 42 extra nucleotides at their 3' ends were able to induce, but to different extents, the synthesis in vitro of the satRNA-encoded 48K protein. However, when inoculated into Chenopodium quinoa together with TBRV L genomic RNAs, only T2GL was biologically active, in the presence or absence of a 5' cap analogue in the transcription reactions. Analysis of the 5' and 3' termini of the satRNA isolated from plants showed that nonviral extensions were not maintained in the transcript progeny.

背景与目标： : 番茄黑环病毒卫星RNA (TBRV satRNA) 的合成转录物，分离物L，是从蓝调转录载体中克隆的cDNA制备的。在其5' 末端具有49个 (T49L) 或两个 (T2GL) 额外核苷酸的转录本以及在其3' 末端具有42个额外核苷酸的转录本能够诱导 (但程度不同) satRNA编码的48K蛋白的体外合成。然而，当与TBRV L基因组rna一起接种到藜藜中时，在转录反应中存在或不存在5' cap类似物的情况下，只有T2GL具有生物活性。对从植物中分离的satRNA的5' 和3' 末端的分析表明，转录本后代中未维持非病毒延伸。

BACKGROUND & AIMS: :Active surveillance and diagnosis of the influenza pandemic (H1N1) 2009 (pH1N1) have played a critical role in the effective control and prevention of the pandemic in China. Although several commercially available real-time PCR kits for pH1N1 virus have been used in diagnostic laboratories in Beijing, little has been known about the performance of these kits for detecting pH1N1 virus. In this study, the performance of two commercial real-time PCR kits in Beijing was evaluated. Analysis of clinical samples showed that the positive detection rate for the AgPath-ID™ kit (38.2%) was significantly higher than that for the Da An H1N1 kit (30.0%) (McNemar's chi-square test, P=0.000). The limit of detection (LOD) of the AgPath-ID™ kit was 10(2), 10(2), and 10(3) copies/reaction for the Influenza A (set 1), H1N1 Influenza A (set 2) and H1N1 Influenza A Sub H1 (set 3) genes, respectively, whereas the LOD of the Da An kit was 10(3) copies/reaction for both H1 and N1 genes. Although the AgPath-ID™ kit exhibited a significantly higher detection rate for pH1N1 than the Da An kit, cross-reactivity to A/PR8/34 was found for the AgPath-ID™ kit for H1N1 Influenza A (set 2).

背景与目标： : 对流感大流行 (H1N1) 2009 (pH1N1) 的积极监测和诊断在有效控制和预防中国大流行方面发挥了关键作用。尽管北京的诊断实验室已经使用了几种市售的pH1N1病毒实时PCR试剂盒，但对这些试剂盒检测pH1N1病毒的性能知之甚少。在这项研究中，评估了北京两种商用实时PCR试剂盒的性能。临床样本分析表明，AgPath-ID的阳性检出率™试剂盒 (38.2%) 显着高于Da H1N1试剂盒 (30.0%) (McNemar卡方检验，P = 0.000)。AgPath-ID的检测极限 (LOD)™试剂盒分别为甲型流感 (第1组) 、甲型H1N1流感 (第2组) 和甲型H1N1流感亚H1 (第3组) 基因的10(2) 、10(2) 和10(3) 拷贝/反应，而Da An试剂盒的LOD对于H1和N1基因均为10(3) 个拷贝/反应。虽然AgPath-ID™试剂盒对pH1N1的检出率明显高于Da一试剂盒，发现AgPath-ID对a/PR8/34的交叉反应性™甲型H1N1流感试剂盒 (第2套)。

BACKGROUND & AIMS: :Chronic hepatitis B virus (HBV) infection afflicts millions worldwide with cirrhosis and liver cancer. HBV e-antigen (HBeAg), a clinical marker for disease severity, is a nonparticulate variant of the protein (core antigen, HBcAg) that forms the building-blocks of capsids. HBeAg is not required for virion production, but is implicated in establishing immune tolerance and chronic infection. Here, we report the crystal structure of HBeAg, which clarifies how the short N-terminal propeptide of HBeAg induces a radically altered mode of dimerization relative to HBcAg (∼140° rotation), locked into place through formation of intramolecular disulfide bridges. This structural switch precludes capsid assembly and engenders a distinct antigenic repertoire, explaining why the two antigens are cross-reactive at the T cell level (through sequence identity) but not at the B cell level (through conformation). The structure offers insight into how HBeAg may establish immune tolerance for HBcAg while evading its robust immunogenicity.

背景与目标： : 慢性乙型肝炎病毒 (HBV) 感染困扰全球数百万肝硬化和肝癌。HBV e抗原 (HBeAg)，疾病严重程度的临床标志物，是形成衣壳的基础结构的蛋白质 (核心抗原，HBcAg) 的非颗粒变体。HBeAg不需要用于病毒粒子的产生，但与建立免疫耐受和慢性感染有关。在这里，我们报告了HBeAg的晶体结构，该结构阐明了HBeAg的短N端前肽如何诱导相对于HBcAg的二聚化模式发生根本改变 (〜140 ° 旋转)，并通过形成分子内二硫键锁定到位。这种结构转换阻止了衣壳的组装并产生了独特的抗原库，解释了为什么这两种抗原在T细胞水平 (通过序列同一性) 而不是在b细胞水平 (通过构象) 交叉反应。该结构提供了深入了解HBeAg如何在逃避其强大的免疫原性的同时建立对HBcAg的免疫耐受性。

BACKGROUND & AIMS: :The Shozu Herpes Zoster (SHEZ) Study was designed to clarify the incidence of and predictive and immunological factors for herpes zoster in a defined community-based Japanese population. As part of this series, a total of 5683 residents aged ≥50 years received a varicella-zoster virus (VZV) skin test with VZV antigen, and 48 h later, the erythema and oedema were assessed by measuring the longest diameter. The diameters of both the erythema and oedema decreased with the increasing age of the subject. Sixty-three subjects contracted herpes zoster within a year after receiving the VZV skin test. Analysis of the herpes zoster incidence rate vs. the skin test reaction revealed that the shorter the diameter of erythema or oedema, the greater the likelihood of herpes zoster. These results demonstrated that the VZV skin test is an excellent surrogate marker for predicting the risk of herpes zoster.

背景与目标： : Shozu带状疱疹 (SHEZ) 研究旨在阐明以社区为基础的日本人群中带状疱疹的发生率以及预测和免疫学因素。作为本系列的一部分，共有5683名年龄 ≥ 50岁的居民接受了VZV抗原的水痘病毒 (VZV) 皮肤测试，48小时后，通过测量最长直径来评估红斑和水肿。随着受试者年龄的增长，红斑和水肿的直径均减小。接受VZV皮肤测试后一年内，有63名受试者感染了带状疱疹。对带状疱疹发病率与皮肤测试反应的分析表明，红斑或水肿的直径越短，带状疱疹的可能性越大。这些结果表明，VZV皮肤测试是预测带状疱疹风险的出色替代指标。

BACKGROUND & AIMS: :Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is organised into minichromosomes by histone and non-histone proteins. Remodelling of minichromosomes is crucial for the regulation of HBV replication, which is dependent on the presence of the hepatitis B virus X protein (HBx). However, the mechanisms of HBx-dependent HBV replication remain obscure. The objective of this study was to investigate the mechanism of HBx-dependent HBV replication through the pathway of chromatin remodelling. The role of HBx was investigated by transfecting human HepG2 cells with the linear full-length HBV genome (wild-type) or HBx-deficient mutant HBV DNA (HBx mutant). Our results showed that although the formation of cccDNA was not affected by HBx, HBV replication, transcription and antigen secretion were all significantly reduced, resulting from the absence of HBx. The acetylation, mono-methylation and phosphorylation of cccDNA-bound histone H3 were associated with HBV replication. In addition, the levels of cccDNA-bound methylated, phosphorylated and acetylated histone H3 decreased sharply in HBx mutant HBV DNA. HBx modulated not only the status of acetylation but also the methylation and phosphorylation of histone H3 bound to the cccDNA during HBV replication in HepG2 cells. These findings suggest that HBx plays an important role in modulating the remodelling of minichromosomes related to HBV replication and it may regulate viral replication through the pathway of chromatin remodelling.

背景与目标： : 乙型肝炎病毒 (HBV) 共价闭合环状DNA (cccDNA) 由组蛋白和非组蛋白组织成微小染色体。微型染色体的重塑对于HBV复制的调节至关重要，这取决于乙型肝炎病毒X蛋白 (HBx) 的存在。然而，HBx依赖性HBV复制的机制仍然不清楚。这项研究的目的是通过染色质重塑途径研究HBx依赖性HBV复制的机制。通过用线性全长HBV基因组 (野生型) 或HBx缺陷型突变型HBV DNA (HBx突变型) 转染人HepG2细胞来研究HBx的作用。我们的结果表明，尽管cccDNA的形成不受HBx的影响，但由于HBx的缺失，HBV复制，转录和抗原分泌均显着降低。cccDNA结合组蛋白H3的乙酰化，单甲基化和磷酸化与HBV复制有关。此外，HBx突变HBV DNA中cccDNA结合的甲基化，磷酸化和乙酰化组蛋白H3的水平急剧下降。HBx不仅调节乙酰化状态，而且调节HepG2细胞中HBV复制过程中与cccDNA结合的组蛋白H3的甲基化和磷酸化。这些发现表明，HBx在调节与HBV复制相关的微小染色体的重塑中起着重要作用，它可能通过染色质重塑途径调节病毒复制。

BACKGROUND & AIMS: :Infectious pancreatic necrosis virus (IPNV), a type species of aquabirnaviruses in the family Birnaviridae, is an etiological agent of infectious pancreatic necrosis and has been isolated from epizootics of cultured salmonids. In the present study, an epithelioma papulosum cyprini (EPC) cell line persistently infected with IPNV (PI-EPC) was experimentally established by subculturing EPC cells surviving IPNV infection, and was characterized. PI-EPC cells were morphologically indistinguishable from EPC, but continued to grow and yield IPNV. PI-EPC cells showed no cytopathic effect due to IPNV inoculation, and susceptibility of PI-EPC cells against heterologous viruses was not different from that of EPC cells. Only one cell of 10(3.5) PI-EPC cells produced IPNV at approximately 10(0.5) 50% tissue culture infectious dose (TCID50)/cell/day, which was approximately 1,000 times lower than that of normal EPC cells. PI-EPC cells that did not yield IPNV (N-PI-EPC) were screened. The IPNV genome was detected from both PI-EPC and N-PI-EPC cells, and the IPNV VP2 structural protein was detected from both cell lines, but no other IPNV proteins were observed by Western blot analysis with anti-IPNV serum. Thus, multiplication of IPNV in PI-EPC cells was regulated by some host cell factors, except interferon.

背景与目标： : 传染性胰腺坏死病毒 (IPNV) 是Birnaviridae家族中的一种aquabirna病毒，是传染性胰腺坏死的病原体，已从培养的鲑鱼的流行病中分离出来。在本研究中，通过传代培养存活IPNV感染的EPC细胞，实验建立了持续感染IPNV (pi-epc) 的丘疹上皮瘤 (EPC) 细胞系，并进行了表征。Pi-epc细胞在形态上与EPC没有区别，但继续生长并产生IPNV。由于IPNV接种，pi-epc细胞没有细胞病变作用，并且pi-epc细胞对异源病毒的敏感性与EPC细胞没有差异。10个 (3.5) pi-epc细胞中只有一个细胞产生约10个 (0.5) 50% 组织培养感染剂量 (TCID50)/细胞/天的IPNV，这比正常EPC细胞低约1,000倍。筛选了未产生IPNV (n-pi-epc) 的PI-EPC细胞。从PI-EPC和N-PI-EPC细胞中检测到IPNV基因组，从两种细胞系中检测到IPNV VP2结构蛋白，但通过抗IPNV血清的Western blot分析未观察到其他IPNV蛋白。因此，除干扰素外，pi-epc细胞中IPNV的增殖受某些宿主细胞因子的调节。

BACKGROUND & AIMS: :The immune-releasing effects of L-glutamine (Gln) supplementation in duck plague virus (DPV)-infected ducklings were evaluated in 120 seven-day-old ducklings that were divided into 8 groups. The ducklings in control and DPV, 0.5Gln and DPV + 0.5Gln, 1.0Gln and DPV + 1.0Gln, and 2.0Gln and DPV + 2.0Gln received 0, 0.5, 1.0, and 2.0 g of Gln/kg feed/d by gastric perfusion, respectively. Then, the ducklings in control to 2.0Gln were injected with 0.2 mL of phosphate-buffered saline, while those in DPV to DPV + 2.0Gln were injected with DPV at 0.2 mL of 2000 TCID50 (50% tissue culture infection dose) 30 minutes after gavage with Gln, sampled at 12 hours and days 1, 2, 4, and 6. Glutamine supplementation under physiological conditions enhanced immune function and toll-like receptor 4 (TLR4) expressions in a dose-dependent manner. An increase in Gln supplementation under DPV-infected conditions enhanced growth performance, decreased immunoglobulin (Ig) release in plasma and secretory IgA in the duodenum, ameliorated plasma cytokine levels, and suppressed overexpressions of the TLR4 pathway in the duodenum. The positive effects of Gln on the humoral immunity- and intestinal inflammation-related damage should be considered a mechanism by which immunonutrition can assist in the recovery from DPV infection.

背景与目标： : 在120 7天大的小鸭中评估了L-谷氨酰胺 (Gln) 补充对鸭瘟病毒 (DPV) 感染的小鸭的免疫释放作用，这些小鸭分为8组。对照组和DPV，0.5Gln和DPV + 0.5Gln，1.0Gln和DPV + 1.0Gln和2.0Gln和DPV + 2.0Gln的雏鸭分别通过胃灌注获得0、0.5、1.0和2.0g Gln/kg饲料/d。然后，将对照至2.0Gln的小鸭注射0.2毫升磷酸盐缓冲盐水，而将DPV至DPV + 2.0Gln的小鸭在TCID50 (50% 组织培养感染剂量) 灌胃30分钟后，在12小时和第1、2天取样，以0.2毫升2000年DPV注射DPV，4，和6。生理条件下补充谷氨酰胺以剂量依赖的方式增强免疫功能和toll样受体4 (TLR4) 的表达。在DPV感染的条件下补充Gln的增加可增强生长性能，降低十二指肠血浆和分泌型IgA中的免疫球蛋白 (Ig) 释放，改善血浆细胞因子水平，并抑制十二指肠TLR4途径的过表达。Gln对体液免疫和肠道炎症相关损害的积极作用应被认为是免疫消耗有助于从DPV感染中恢复的机制。