毛壳素显著抑制柯萨奇病毒 B3的体外复制

柯萨奇病毒B3（CVB3）是一种常见的人类病原体,与多种疾病有关。本研究旨在探讨球毛壳菌代谢产物毛壳素对CVB3在体外培养细胞系中复制的影响。结果显示,毛壳素显著抑制CVB3在体外培养细胞系中的复制。250 nmol/L毛壳素可使 CVB3感染的 HeLa细胞相对存活率从未加毛壳素时的（21．9±1．8）％提高至（70．1±4．3）％。同时,毛壳素处理的HeLa细胞中病毒产量仅为对照组的（5．3±0．8）％,而病毒RNA水平也仅为对照组的（13．0±8．3）％。毛壳素也可使CVB3感染的Vero细胞相对存活率从（64．6±1．7）％提高至（87．2±4．8）％。毛壳素的这种抑制作用可被抗氧化剂 N-乙酰半胱氨酸部分抑制。研究毛壳素抑制病毒复制的具体作用机制将有助于新型抗病毒药物的研制。     

A型流感病毒逃避免疫应答的策略

综述了IAV逃避抗病毒免疫策略的最新进展．A型流感病毒（IAV）感染是人和多种动物呼吸系统疾病的主要原因,然而不管是IAV引起的季节性流感暴发还是周期性的全球流感大流行,主要归因于IAV逃避宿主免疫反应的策略．越来越多的证据表明,IAV已经进化出高超的策略克服宿主的抗病毒信号,如抗原变异和编码辅助蛋白（NS1和PB1-F2）．深入理解IAV逃避宿主免疫的策略,有助于揭示IAV感染的机制和发现针对IAV的抗病毒药物的靶标．     

SARS冠状病毒的Spike蛋白以及病毒的细胞侵入机制

严重急性呼吸系统综合征（SARS）是由SARS冠状病毒（SARS—CoV）引起的一种新型人类疾病,具有高致病性、高传染性、高死亡率的特点。Spike蛋白是冠状捅毒膜表面的糖蛋白突出,构成病毒的包膜子粒,在病毒与其受体结合、通过膜融合进入宿主细胞以及诱导机体产生中和性抗体的过程中发挥着重要的作用：目前利用Spike蛋白开发出的一些防治SARS的药物和疫苗在动物和体外实验中有良好的抗病毒作用。本文阐述了SARS—CoV Spike蛋白的结构与功能,为抗SARS药物及疫苗的研发提供一定的理论基础.     

肠热症传播的生态学要素、流行病学因素与控制策略

肠热症（Enteric fever）包括伤寒（Typhoid fever）和副伤寒（Paratyphoid fever）,伤寒是由肠沙门菌肠亚种伤寒血清型（Salmonella enterica subsp．enterica serotype typhi）引起的肠道传染病,副伤寒是由肠沙门菌肠亚种副伤寒甲或乙或丙血清型（Salmonella enterica subsp．enterica serotype paratyphiA,B,C）引起和伤寒相似但症状较轻的疾病。人是肠热症病原菌的唯一天然宿主,该病原菌已进化成能高度适应人类宿主内环境的特异性细菌（具有在人机体内存活的机制,不会在人体外环境中无限存活）,仅感染人类,     

汉坦病毒的致病性和免疫应答以及抗病毒和疫苗研究进展——第四届汉坦病毒国际会议部份内容介绍

第四届肾综合征出血热（ＨＦＲＳ）和汉坦病毒国际会议于１９９８年３月５日～７日在美国亚特兰大召开,会议共有９个专题。本文就汉坦病毒的致病性和免疫应答以及疫苗和抗病毒药物的研究现状以及最新进展作一简单介绍：研究较为深入的有美国引起汉坦病毒肺综合征的ＳｉｎＮｏｍｂｒｅ病毒,至今已确诊病例１７０多例,它的致病机理认为是由Ｔ细胞介导的免疫病理所致,而与我国由ＨＴＮ病毒引起的肾综合征出血热是由抗原抗体复合物引起的免疫病理有差异。汉坦病毒肺综合征不但由鼠传播,而且最新有证据表明ＳｉｎＮｏｍｂｒｅ病毒可经口人－人间传播,给预防和控制本病增加了困难。本文还介绍了疫苗免疫后的效果以及抗病毒药物的作用机理及效果     

全球抗病毒药物研发进展与展望

病毒是危害人体健康的主要病原体之一,病毒感染和传播造成的传染性疾病严重威胁人类健康。目前,艾滋病、病毒性肝炎等发病率高、治愈率低的病毒性疾病仍在全球蔓延,流感病毒、冠状病毒等呼吸道病毒不断发生变异,2019年以来,新冠病毒引起的全球疫情对世界各国产生巨大影响,疫情走向还存在很大不确定性,开发安全有效的抗病毒药物成为应对病毒性疾病的重要手段。拟在总结全球抗病毒药物研发整体现状的基础上,分析抗艾滋病病毒、肝炎病毒、新冠病毒等重点领域的新药研发进展,提出抗病毒药物的发展建议,为未来研发更加高效的抗病毒药物提供指引和参考。     

疱疹病毒对抗病毒药物抗性的回顾

本文就单纯疱疹病毒（ＨＳＶ）、水痘带状疱疹病毒（ＶＺＶ）、人巨细胞病毒（ＨＣＭＶ）、ＥＢ病毒（ＥＢＶ）等疱疹病毒的抗病毒药物,产生抗性的机理和抗病毒治疗的策略等方面进行了回顾。     

综述与专论: 认知行为疗法和虚拟现实疗法干预神经性疼痛的作用及机制

神经性疼痛（neuropathic pain，NP）是由外周或中枢躯体感觉系统的损伤或疾病导致的疼痛。药物治疗在镇痛中占据重要地位，但是过量药物治疗往往会引起严重的副作用，或在可耐受剂量下仅提供了部分的疼痛缓解。认知行为疗法（cognitive-behavioral therapy，CBT）和虚拟现实（virtual reality，VR）干预作为新的、非侵入性的，以及更为安全的疼痛替代治疗方法引起了广泛的关注。CBT和VR疗法可通过转移注意力、改变神经可塑性和神经环路，以及调节促炎和抗炎因子水平缓解神经性疼痛。本文旨在对神经性疼痛的发病机制以及CBT和VR疗法的镇痛效果和机制做出解析，从而为神经性疼痛的治疗干预提供重要的理论指导。     

国家“重大新药创制”科技重大专项重点关注靶点分析解读——PI3K-Akt-mTOR 通路

由磷脂酰肌醇3- 激酶（PI3K）、丝氨酸/ 苏氨酸蛋白激酶（Akt）和哺乳动物雷帕霉素靶蛋白（mTOR）组成的PI3K-Akt-mTOR通路是细胞内非常重要的信号转导途径,该通路的紊乱会引起一系列的疾病,包括癌症、神经病变、自身免疫性疾病和血液淋巴系统疾病。近年来,PI3K-Akt-mTOR 通路作为药物靶点备受关注。结合汤森路透数据库资源——Thomson Reuters Integrity 和Cortellis for Competitive Intelligence,对PI3K-Akt-mTOR 通路的机制、相关药物研究进展、适应证、研发公司、交易、专利、文献等情报进行了数据层面的分析。     

伤寒和副伤寒的流行、诊断、治疗和预防

伤寒是由肠沙门菌肠亚种伤寒血清型（Salmonella enterica subsp．enterica serotype typhi）引起的肠道传染病。副伤寒是由肠沙门菌肠亚种副伤寒甲或乙或丙血清型（Salmonella enteriea subsp．entelica serotype paratyphi A,B,C）引起的一种和伤寒相似但症状较轻的疾病。伤寒和副伤寒病原菌已进化成能高度适应人类宿主内环境的特异性细菌,     

Virus-like particle capsid proteins encoded by different L double-stranded RNAs of Saccharomyces cerevisiae: their roles in maintenance of M double-stranded killer plasmids.

The plasmid determinants of killer phenotypes in type K1 and K2 killer yeast cells are the 1.9-kilobase (kb) M1 and 1.7-kb M2 double-stranded RNAs (dsRNAs), respectively. These are dependent for their maintenance and encapsidation, in Saccharomyces cerevisiae virus ScV-M1 or ScV-M2 virus-like particles, on the capsid provided by one of a group of moderately related 4.7-kb dsRNAs called LA. The L1A and L2A dsRNAs found in naturally isolated K1 and K2 killers encode 88-kilodalton VL1A-P1 and 86-kilodalton VL2A-P1 capsids, respectively. These are competent for encapsidating homologous LA dsRNAs as well as M dsRNAs. Most strains of S. cerevisiae, including killers, contain one of a second group of closely related 4.7-kb dsRNAs called LBC. These encode their own 82-kilodalton capsid protein, VLBC-P1, which, at least in strains containing only LBC, encapsidates homologous dsRNA in ScV-LBC virus-like particles. In a K1 killer strain containing both L1A and LBC, ScV-M1 particles contain only VL1A-P1. In such strains it is probable that each virus-like particle contains a single capsid type and that each L dsRNA is encapsidated by a homologous capsid.     

The dynamics of 2',5'-oligoadenylate synthetase activity in the nuclear and cytoplasmic fractions of human fibroblasts treated by double-stranded RNAs, by their complexes with DEAE-dextran and by type-I recombinant interferons. The ratio of double-stranded RNA-activated and -nonactivated froms of the enzyme

Novel original preparations of double-stranded RNAs (dsRNAs), i.e. larifan, ridostin and rifastin, and recombinant alpha 2- and beta-interferons promising for the clinical use were studied. The size and morphology of the dsRNAs in the preparation composition, the dynamics of their induction of interferon and the antiviral state in human fibroblasts and the effect of the DEAE dextran polycation on the activity of the dsRNAs were specified. For the first time the dynamics of 2',5'-oligoadenylate synthetase activity in the nuclei and cytoplasm of the human fibroblasts treated with the dsRNAs of different origin and their complexes with DEAE dextran was defined. To elucidate the specific features of the mechanism of antiviral action of dsRNAs and interferon, the relation of the 2',5'-oligoadenylate synthetase activity to dsRNAs was investigated. In the cells treated with dsRNAs and DEAE dextran there were an early activation of the enzyme and predominance of the enzyme activated forms requiring no addition of poly I.poly C to the reaction mixture. The results were indicative of possible intracellular activation of its isoforms, similar to that in the cells treated with interferon and contaminated with viruses. All the tested preparations of dsRNAs and interferons induced an increase in the activity of 2',5'-oligoadenylate synthetase both in the cytoplasm and the nuclei of human fibroblasts. The same ability was observed in DEAE dextran which is likely to be one of the causes of the increase in dsRNAs antiviral activity under its effect.     

Cell-free translation system from Drosophila S2 cells that recapitulates RNAi

RNA interference (RNAi) is a fundamental mechanism of gene regulation in a variety of organisms. In Drosophila cells, long double-stranded RNAs (dsRNAs) are processed into 21- to 23-nucleotide double-stranded fragments, termed short interfering RNAs (siRNAs). The siRNAs trigger sequence-specific mRNA degradation, which results in the inhibition of gene expression. These phenomena can be recapitulated in vitro in lysates of Drosophila syncytial blastoderm embryos. In the present work, we used the common Drosophila cell line, Schneider Line 2 (S2), as a source to establish a cell-free translation system. We demonstrate here that the S2 cell-free translation system can recapitulate RNAi. Both long dsRNAs and siRNAs can trigger RNAi in this system, and the silencing effects are significant. This system should provide an important tool for biochemical analyses of the RNAi mechanism.     

Modified 27-nt dsRNAs with dramatically enhanced stability in serum and long-term RNAi activity

The present study describes improved properties of 27-nt dsRNAs over 21-nt siRNAs, and accents on the possibility to use their modifications and conjugates for direct long-term gene silencing in viable cells and animals, avoiding conventional transfectants. Using a Renilla Luciferase gene-silencing system and cultured cell lines, we established that 27-nt dsRNAs possessed about three to five times higher "long-term" RNAi activity than 21-nt siRNAs and 21-nt dsRNAs. Moreover, if RNA duplexes were preincubated with cell-cultured medium for several hours before their transfection in cells, 21-mer completely lost its RNAi effect, while 27-mer, its amino modifications, thiol modifications, and cholesterol conjugates manifested a strong gene silencing. In attempts to clarify the reason(s) for the higher RNAi activity of 27-nt dsRNAs, we found that they were approximately 100 times more stable than 21-nt siRNA and 21-nt dsRNA in cell-cultured medium supplemented with 10% inactivated serum, approximately 50 times more stable in 90% inactivated serum, and approximately six times more stable in active serum. The 5' sense modification was selected as the most stable, accessible to Dicer, and with highest RNAi potential. The RNAi activity of 5' sense modifications was higher even than the activity of nonmodified 27-nt dsRNA. The 5' sense amino modification also did not influence the activity of 21-nt siRNA, right overhang 25/27-nt (R25D/27), and 25D/27-nt RNAs. The stability of 5' sense modified R25D/27-nt and 25D/27-nt RNAs in serum was lower than that of blunt 27-nt dsRNA. However, these asymmetric RNAs were more active than modified and nonmodified blunt 27-nt dsRNAs, which demonstrates the superiority of the asymmetric design. The 5' sense modifications were considered as most appropriate for conjugation with small signal molecules to facilitate the intracellular delivery of RNA duplex, to preserve its RNAi capacity, and to ensure a possibility for rapid long-term gene silencing in viable cells and animals. The 5' sense conjugation with cholesterol approved this assumption.     

The p53-induced Wig-1 protein binds double-stranded RNAs with structural characteristics of siRNAs and miRNAs

Wig-1 is a p53-induced zinc finger protein. Here we show that human Wig-1 binds long (>or=23 bp) dsRNAs with 5'-overhangs. The first zinc finger domain is necessary but not sufficient for this dsRNA-binding in vitro. Wig-1 also binds dsRNA in living cells via zinc fingers 1 and 2. Both zinc fingers 1 and 2 are important for Wig-1-mediated growth suppression. Moreover, Wig-1 binds 21 bp dsRNAs with 3'-protruding ends. These findings demonstrate that human Wig-1 can bind different types of dsRNAs, including dsRNAs resembling small interfering RNAs (siRNAs) and microRNAs (miRNAs), and indicate that dsRNA binding has a role in Wig-1-mediated regulation of cell growth.     

A Study of the Transmission and Structure of Double Stranded Rnas Associated with the Killer Phenomenon in SACCHAROMYCES CEREVISIAE

Killer strains contain two double stranded RNAs, L and M. The M dsRNA appears to be necessary for production of a toxin and for resistance to that toxin. Mutant strains have been found that are defective in their ability to kill and in their resistance to toxin. These sensitive, non-killer strains have altered dsRNA composition. One class has no M dsRNA. Another class of sensitive, non-killers called suppressives has no M dsRNA but instead has smaller dsRNAs called S. In diploids resulting from a cross of a wild-type killer by a suppressive the transmission of the M dsRNA is suppressed by the S dsRNA. When a suppressive is crossed by a strain with no M dsRNA, the diploids and all four meiotic spores have the S dsRNA characteristic of the parental suppressive strain. Suppressive strains do not suppress each other. Intercrosses between two different suppressives yields diploids with both parental S dsRNAs. These two S dsRNAs are transmitted to all 4 meiotic progeny. Another class of mutants has been found which is defective for one of the traits but retains the other. One type, temperature-sensitive killers, has a normal dsRNA composition but is unable to kill at 30°. The other type, immunity-minus, has a complex dsRNA pattern. The immunity-minus strain is extremely unstable during mitotic growth and segregates several different types of non-killers. Analysis of the dsRNAs from wild type and the mutants by electron microscopy shows that the L, M, and S dsRNAs are linear. All strains regardless of killer phenotype appear to have the same size L dsRNA.     

Evidence of Aberrant Immune Response by Endogenous Double‐Stranded RNAs: Attack from Within

Many innate immune response proteins recognize foreign nucleic acids from invading pathogens to initiate antiviral signaling. These proteins mostly rely on structural characteristics of the nucleic acids rather than their specific sequences to distinguish self and nonself. One feature utilized by RNA sensors is the extended stretch of double‐stranded RNA (dsRNA) base pairs. However, the criteria for recognizing nonself dsRNAs are rather lenient, and hairpin structure of self‐RNAs can also trigger an immune response. Consequently, aberrant activation of RNA sensors has been reported in numerous human diseases. Yet, in most cases, the activating antigens remain unknown. Recent studies have developed sequencing techniques tailored to specifically capture dsRNAs and identified that various noncoding elements in the nuclear and the mitochondrial genome can generate dsRNAs. Here, the identity of endogenous dsRNAs, their recognition by dsRNA sensors, and their implications in the pathogenesis of human diseases ranging from inflammatory to degenerative are presented.     

Matter arising: off-targets and genome-scale RNAi screens in Drosophila

Recently, the issue of off-target effects (OTEs) associated with long double stranded RNAs (dsRNAs) used in RNAi screens, such as those performed at the Drosophila RNAi Screening Center and other laboratories, has become a focus of great interest and some concern. Although OTEs have been recognized as an important source of false positives in mammalian studies (where short siRNAs are used as triggers), they were generally thought to be inconsequential in Drosophila RNAi experiments because of the use of long dsRNAs. Two recent papers have disputed this contention and show that significant off-target effects can take place with the use of some long dsRNAs in Drosophila cells. Together, these studies provide evidence that OTEs mediated by short homology stretches of 19nt or greater within long dsRNAs can contribute to false positives in Drosophila RNAi screens. Here, we address how widespread the occurrence of OTE is in Drosophila screens, focusing on the DRSC dsRNA collections, and we discuss the implication for the interpretation of results reported in RNAi screens to-date. Lastly, we summarize steps taken by the DRSC to redress that situation and include a set of recommendations to observe in future RNAi screens.