单纯疱疹病毒与天然免疫系统的相互作用的研究进展

单纯疱疹病毒(Herpes simplex virus,HSV)包括1型和2型,属于人类疱疹病毒家族的α亚族,也是人类感染最常见的病原体之一,感染可导致多种疱疹性疾病,包括疱疹性眼炎及可引起失明的疱疹性角膜炎。HSV的致病机制与病毒和宿主天然免疫系统的相互作用密切相关,涉及到病毒逃逸干扰素反应,核转录因子κB(Nuclear factorκB,NF-κB)信号通路以及病毒与免疫细胞相互作用等多个环节。本文就近年来单纯疱疹病毒与天然免疫系统的相互作用的研究进展进行综述。     

2型单纯疱疹病毒体外感染周期的研究进展

2型单纯疱疹病毒(Herpes simplex virus type 2,HSV-2)是引起生殖器疱疹的主要病原体。生殖器疱疹主要表现为生殖器和肛周皮肤黏膜疱疹或溃疡,是一种慢性、复发性、难以治愈的性传播疾病,临床治疗多以抑制病毒复制的核苷类药物阿昔洛韦及其衍生物更昔洛韦、喷昔洛韦等为主。这些药物对缓解症状、缩短病程有一定作用,但难以达到根治的目的,长期应用易产生耐药,且对其合并症基本无效。作用于HSV-2其他感染周期的药物成为人类探索的新领域。HSV-2感染宿主细胞是一个复杂的多阶段过程,包括黏附、穿入、核转运、基因组复制、衣壳组装、子代病毒释放等多个步骤,涉及多种细胞和病毒蛋白的活性。本文对HSV-2体外感染周期详细步骤及其分子机制作一综述,以期深入了解其感染机制,并为研制作用于不同感染阶段的抗HSV-2药物提供参考。     

鲤疱疹病毒3型研究进展

鲤疱疹病毒3型(Cyprinid herpesvirus 3,CyHV-3)是引起高度传染性锦鲤疱疹病毒病(Koi herpesvirus disease,KHVD)的病原,该病毒自1997年首次报道以来,在全球多个国家传播、流行,范围覆盖亚洲、欧洲、北美及非洲多个国家,给鲤鱼及锦鲤养殖业造成无可估量的经济损失。本文就鲤疱疹病毒3型的病原学、流行病学、感染机制、诊断及防控等方面的研究进行简要综述,以期为鲤疱疹病毒3型基础研究和疾病防控策略的建立提供参考信息。     

HSV I感染L-02细胞对核不均一性核糖核蛋白H2(hnRNP H2)表达影响

单纯疱疹病毒(HSV I)对宿主细胞转录及mRNA修饰翻译通路的调控是一个系统的、复杂的体系,探索其具体机制将有助于了解病毒复制过程及与宿主细胞之间的相互作用.基于2-DE分析,人正常肝细胞L-02细胞核不均一性核糖核蛋白H2(heterogeneous nuclear ribonucleoprotein H2,hnRNP H2)在感染HSV I前后存在表达差异,通过 Western blot,Northernblot等技术方法验证其在病毒复制过程中不同时段对其表达影响.     

HSV I感染L-02细胞对核不均-性核糖核蛋白H2（hnRNP H2）表达影响

单纯疱疹病毒（HSV I）对宿主细胞转录及mRNA修饰翻译通路的调控是一个系统的、复杂的体系,探索其具体机制将有助于了解病毒复制过程及与宿主细胞之间的相互作用。基于2-DE分析,人正常肝细胞L-02细胞核不均一性核糖核蛋白H2（heterogeneous nuclear ribonucleoprotein H2,hnRNPI-12）在感染HSVI前后存在表达差异,通过Western blot,Northern blot等技术方法验证其在病毒复制过程中不同时段对其表达影响。     

鸭肠炎病毒gB基因的分子特征

鸭肠炎病毒是鸭病毒性肠炎的病原,被划分为疱疹病毒科成员.gB是疱疹病毒感染和复制所必需的糖蛋白,能刺激机体产生中和抗体和细胞免疫应答,在疱疹病毒家族中高度保守.通过PCR技术获得了DEV C-KCE株gB基因的核苷酸序列,首次对DEV gB基因及编码氨基酸进行了较为详尽的生物信息学分析.结果表明,DEV gB基因与α-疱疹病毒的马立克氏病毒属亲缘关系最近;DEV gB蛋白具有与其他疱疹病毒gB相同或相似的结构、N糖基化位点、半胱氨酸残基、硫酸乙酰肝素蛋白聚糖(HSPGs)结合位点、弗林蛋白酶水解位点和胞浆区PACS-1识别位点.     

疱疹病毒科研究进展

疱疹病毒是一类大型双链DNA病毒.至今已发现9种疱疹病毒可感染人类,分别是单纯疱疹病毒1型、2型(HSV-1、2)、带状疱疹病毒(VZV)、EB病毒(EBV)、人巨细胞病毒(HCMV),以及人疱疹病毒(HHV)-6A、HHV-6B、HHV-7、卡波济肉瘤相关病毒(HHV-8)等,它们是已知感染人类的病毒种类数最多的一个病毒科.     

HSVⅠ感染L-02细胞对核不均一性核糖核蛋白H2（hnRNP H2）表达影响

单纯疱疹病毒（HSVⅠ）对宿主细胞转录及mRNA修饰翻译通路的调控是一个系统的、复杂的体系,探索其具体机制将有助于了解病毒复制过程及与宿主细胞之间的相互作用。基于2-DE分析,人胎肝细胞 L-02细胞核不均一性核糖核蛋白H2（heterogeneous nuclear ribonucleoprotein H2,hnRNP H2）在感染HSVⅠ前后存在表达差异,通过Western blot ,Northern blot等技术方法验证其在病毒复制过程中不同时段对其表达影响。     

鼠γ疱疹病毒68(MHV68):研究γ疱疹病毒感染的模型

γ疱疹病毒成员遍及自然界,可感染包括人在内的多种哺乳动物.γ疱疹病毒的生物学特性主要有:(1)能在淋巴细胞中潜伏感染;(2)可以产生淋巴增生性疾病;(3)与淋巴组织和非淋巴组织肿瘤关系密切.最开始γ疱疹病毒根据感染T或B细胞的不同而分为γ1和γ2疱疹病毒,前者主要感染B淋巴细胞,如感染人和棉顶绒猴的EBV(EpsteinBarr virus);γ2疱疹病毒则感染T淋巴细胞,以感染松鼠猴的疱疹病毒samiri(herpesvirus samiri,HVS)为代表.但后来证实γ2疱疹病毒可同时感染T、B淋巴细胞,而EBV亦可引起T淋巴细胞肿瘤.因此以后发现的γ疱疹病毒则根据其基因结构及基因组中代表性序列的特点,将其归为γ1或γ2亚类.如感染人的卡波氏肉瘤相关病毒(Kaposi's sarcomaassociated herpesvirus,KSHV)或称人疱疹病毒8(human herpesvirus-8,HHV8)就归为γ2[1].     

埃巴病毒潜伏膜蛋白的研究进展

埃巴病毒(Epstein-Barr Virus, EBV)是一种在人群中感染率高达90%的γ-疱疹病毒,其感染宿主细胞后常以潜伏形式存在并伴随终生,在一定条件诱导下,由潜伏感染转化为裂解感染,导致多种恶性肿瘤的发生。LMP1和LMP2是EBV编码的重要潜伏膜蛋白,它们锚定于细胞膜脂筏区,通过与宿主细胞内多种信号传递分子如TRAF家族蛋白、Caspase家族蛋白和STAT家族等相互作用,参与细胞内多条信号转导通路,进而影响细胞迁移与凋亡,与淋巴组织增生性疾病和恶性肿瘤的发生有着密切联系。本文阐述了LMP1和LMP2的结构特征,在宿主细胞内的基因表达调控及参与信号转导途径的机制等,旨在推进EBV发病机理研究及疫苗的研发等科研进展。     

Detection of herpes simplex virus by DNA-DNA hybridization method]

Eight recombinant clones were obtained by insertion of BamHI fragments of herpes simplex type I viral DNA into a vector plasmid pUC19o. Of the obtained clones 5 were found to hybridize with herpes simplex type I and 2 viral DNA while 3 clones revealed a positive reaction with the Vero cells DNA. A constructed DNA-probe possessing the highest level of activity was selected for further studies. The probe is a BamHI fragment of herpes simplex type I viral DNA labelled with 32P dTTP. Probe sensitivity in blot hybridization is 10 pg for identification of type I viral DNA and 50 pg for type 2 viral DNA. The DNAs of cytomegalovirus and herpes zoster virus do not show positive signals with the probe. The increased sensitivity of the used dot hybridization as compared with biological or IEA antigen identification of the virus was confirmed with the clinical material from 59 patients with the different clinical manifestations of the herpes viral infection.     

Virucidal effect of peppermint oil on the enveloped viruses herpes simplex virus type 1 and type 2 in vitro

The virucidal effect of peppermint oil, the essential oil of Mentha piperita, against herpes simplex virus was examined. The inhibitory activity against herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) was tested in vitro on RC-37 cells using a plaque reduction assay. The 50% inhibitory concentration (IC50) of peppermint oil for herpes simplex virus plaque formation was determined at 0.002% and 0.0008% for HSV-1 and HSV-2, respectively. Peppermint oil exhibited high levels of virucidal activity against HSV-1 and HSV-2 in viral suspension tests. At noncytotoxic concentrations of the oil, plaque formation was significantly reduced by 82% and 92% for HSV-1 and HSV-2, respectively. Higher concentrations of peppermint oil reduced viral titers of both herpesviruses by more than 90%. A clearly time-dependent activity could be demonstrated, after 3 h of incubation of herpes simplex virus with peppermint oil an antiviral activity of about 99% could be demonstrated. In order to determine the mode of antiviral action of the essential oil, peppermint oil was added at different times to the cells or viruses during infection. Both herpesviruses were significantly inhibited when herpes simplex virus was pretreated with the essential oil prior to adsorption. These results indicate that peppermint oil affected the virus before adsorption, but not after penetration into the host cell. Thus this essential oil is capable to exert a direct virucidal effect on HSV. Peppermint oil is also active against an acyclovir resistant strain of HSV-1 (HSV-1-ACV(res)), plaque formation was significantly reduced by 99%. Considering the lipophilic nature of the oil which enables it to penetrate the skin, peppermint oil might be suitable for topical therapeutic use as virucidal agent in recurrent herpes infection.     

Genetic analysis of temperature-sensitive mutants which define the gene for the major herpes simplex virus type 1 DNA-binding protein.

We have assigned eight temperature-sensitive mutants of herpes simplex virus type 1 to complementation group 1-1. Members of this group fail to complement mutants in herpes simplex virus type 2 complementation group 2-2. The mutation of one member of group 1-1, tsHA1 of strain mP, has been shown to map in or near the sequence which encodes the major herpes simplex virus type 1 DNA-binding protein (Conley et al., J. Virol. 37:191-206, 1981). The mutations of five other members of group 1-1 map in or near the sequence in which the tsHA1 mutation maps, a sequence which lies near the center of UL between the genes for the viral DNA polymerase and viral glycoprotein gAgB. These mutants can be divided into two groups; the mutations of one group map between coordinates 0.385 and 0.398, and the mutations of the other group map between coordinates 0.398 and 0.413. At the nonpermissive temperature mutants in group 1-1 are viral DNA negative, and mutant-infected cells fail to react with monoclonal antibody to the 130,000-dalton DNA-binding protein. Taken together, these data indicate that mutants in complementation groups 1-1 and 2-2 define the gene for the major herpes simplex virus DNA-binding protein, an early gene product required for viral DNA synthesis.     

Neutralizing antibodies specific for glycoprotein H of herpes simplex virus permit viral attachment to cells but prevent penetration.

Monoclonal antibodies specific for gH of herpes simplex virus were shown previously to neutralize viral infectivity. Results presented here demonstrate that these antibodies (at least three of them) block viral penetration without inhibiting adsorption of virus to cells. Penetration of herpes simplex virus is by fusion of the virion envelope with the plasma membrane of a susceptible cell. Electron microscopy of thin sections of cells exposed to virus revealed that neutralized virus bound to the cell surface but did not fuse with the plasma membrane. Quantitation of virus adsorption by measuring the binding of purified radiolabeled virus to cells revealed that the anti-gH antibodies had little or no effect on adsorption. Monitoring cell and viral protein synthesis after exposure of cells to infectious and neutralized virus gave results consistent with the electron microscopic finding that the anti-gH antibodies blocked viral penetration. On the basis of the results presented here and other information published elsewhere, it is suggested that gH is one of three glycoproteins essential for penetration of herpes simplex virus into cells.     

Oncogenic Transformation of Hamster Cells after Exposure to Herpes Simplex Virus Type 2

THE possibility of a relationship between herpes simplex viruses (HSV) and human cancer has been suggested^1–4 chiefly on the basis of studies of the epidemiology of cervical cancer, but so far it has not been possible to demonstrate that human herpes viruses can induce primary transformation of normal cells. Injection of herpes simplex virus type 1 (ref. 5) or type 2 (ref. 6) into Syrian hamsters rarely leads to the production of a tumour and it has been difficult to demonstrate herpes viral antigens in tumour cells. Human herpes simplex viruses grown in vitro are characterized by the rapidity with which the infected cell is destroyed, so that cell transformation is impossible, but this effect can be mitigated by inactivation of the herpes virus by ultraviolet irradiation. Indeed, this procedure may have the additional advantage that viral infectivity is removed more quickly than the viral transforming potential⁷.     

The incorporation of 5-iodo-5'-amino-2',5-dideoxyuridine and 5-iodo-2'-deoxyuridine into herpes simplex virus DNA. Relationship between antiviral activity and effects on DNA structure

Isopycnic centrifugation in CsCl gradients was used to quantify the incorporation of 5-iodo-5'-amino-2',5'-dideoxyuridine and 5-iodo-2'-deoxyuridine into herpes simplex virus type 1 DNA. A parallelism between the degree of incorporation into viral DNA and the inhibition of herpes simplex virus type I replication was found for both thymidine analogs. A concentration of 5-iodo-5'-amino-2',5'-dideoxyuridine approximately 100 times greater than 5-iodo-2'-deoxyuridine was required to achieve similar levels of antiviral activity. However, the inhibitory effects of these compounds are similar when compared with respect to the percent of substitution for thymidine in herpes simplex virus type I DNA. Damage to the viral DNA, as indicated by the presence of single or double-stranded breaks, was assessed by centrifugation in alkaline and neutral sucrose gradients. The incorporation of 5-iodo-5'-amino-2',5'-dideoxyuridine into herpes simplex virus type I DNA produced single and, to a lesser extent, double-stranded breaks in a dose-dependent manner. 5-Iodo-2'-deoxyuridine did not, however, induced DNA breakage. These data indicate that the additional presence of a phosphoramidate bond in the DNA produced the extensive damage detected under these conditions, but that such damage is not required for antiviral activity.     

Herpes simplex virus type 1 capsid protein VP26 interacts with dynein light chains RP3 and Tctex1 and plays a role in retrograde cellular transport

Cytoplasmic dynein is the major molecular motor involved in minus-end-directed cellular transport along microtubules. There is increasing evidence that the retrograde transport of herpes simplex virus type 1 along sensory axons is mediated by cytoplasmic dynein, but the viral and cellular proteins involved are not known. Here we report that the herpes simplex virus outer capsid protein VP26 interacts with dynein light chains RP3 and Tctex1 and is sufficient to mediate retrograde transport of viral capsids in a cellular model. A library of herpes simplex virus capsid and tegument structural genes was constructed and tested for interactions with dynein subunits in a yeast two-hybrid system. A strong interaction was detected between VP26 and the homologous 14-kDa dynein light chains RP3 and Tctex1. In vitro pull-down assays confirmed binding of VP26 to RP3, Tctex1, and intact cytoplasmic dynein complexes. Recombinant herpes simplex virus capsids were constructed either with or without VP26. In pull-down assays VP26+ capsids bound to RP3; VP26-capsids did not. To investigate intracellular transport, the recombinant viral capsids were microinjected into living cells and incubated at 37 degrees C. After 1 h VP26+ capsids were observed to co-localize with RP3, Tctex1, and microtubules. After 2 or 4 h VP26+ capsids had moved closer to the cell nucleus, whereas VP26-capsids remained in a random distribution. We propose that VP26 mediates binding of incoming herpes simplex virus capsids to cytoplasmic dynein during cellular infection, through interactions with dynein light chains.     

Differentiation Between Herpes Simplex Virus Type 1 and Type 2 Strains by Immunoelectroosmophoresis

A method has been elaborated to differentiate between herpes simplex type 1 and type 2 viruses by immunoelectroosmophoresis. With rabbit immune sera cross-absorbed with heterologous virus antigen, a distinct difference was shown between the two virus types. Herpes simplex type 1 virus tested against cross-absorbed type 1 antiserum gave two precipitin lines. Herpes simplex type 2 virus gave one precipitin line when tested against cross-absorbed homologous serum. When the viral antigens were tested against cross-absorbed heterologous immune sera, no or only very weak precipitin reactions were observed. The test is easy and rapid, requires relatively small quantities of antigen and antibody, and is suitable for typing of herpes simplex virus in diagnostic routine work.     

Crystal structure of the herpes simplex virus 1 DNA polymerase

Herpesviruses are the second leading cause of human viral diseases. Herpes Simplex Virus types 1 and 2 and Varicella-zoster virus produce neurotropic infections such as cutaneous and genital herpes, chickenpox, and shingles. Infections of a lymphotropic nature are caused by cytomegalovirus, HSV-6, HSV-7, and Epstein-Barr virus producing lymphoma, carcinoma, and congenital abnormalities. Yet another series of serious health problems are posed by infections in immunocompromised individuals. Common therapies for herpes viral infections employ nucleoside analogs, such as Acyclovir, and target the viral DNA polymerase, essential for viral DNA replication. Although clinically useful, this class of drugs exhibits a narrow antiviral spectrum, and resistance to these agents is an emerging problem for disease management. A better understanding of herpes virus replication will help the development of new safe and effective broad spectrum anti-herpetic drugs that fill an unmet need. Here, we present the first crystal structure of a herpesvirus polymerase, the Herpes Simplex Virus type 1 DNA polymerase, at 2.7 A resolution. The structural similarity of this polymerase to other alpha polymerases has allowed us to construct high confidence models of a replication complex of the polymerase and of Acyclovir as a DNA chain terminator. We propose a novel inhibition mechanism in which a representative of a series of non-nucleosidic viral polymerase inhibitors, the 4-oxo-dihydroquinolines, binds at the polymerase active site interacting non-covalently with both the polymerase and the DNA duplex.     

Molecular genetics of herpes simplex virus. VIII. further characterization of a temperature-sensitive mutant defective in release of viral DNA and in other stages of the viral reproductive cycle.

Previous studies have shown that cells infected with the herpes simplex virus 1(HFEM) mutant tsB7 and maintained at the nonpermissive temperature fail to accumulate viral polypeptides. Analyses of intertypic recombinants generated by marker rescue of tsB7 with herpes simplex virus 2 DNA fragments localized the mutation between 0.46 and 0.52 map units on the viral genome (Knipe et al., J. Virol. 38:539-547, 1981). In this paper we report that the mutation in tsB7 affects several aspects of the reproductive cycle of the virus at the nonpermissive temperature. Thus, (i) viral capsids accumulate at the nuclear pores and do not release viral DNA for at least 6 h postinfection at 39 degrees C. The DNA was released within 30 min after a shift to the permissive temperature. (ii) Experiments involving shifts from the permissive to the nonpermissive temperature indicated that viral protein synthesis was not sustained in cells maintained at the permissive temperature for less than 4 h. (iii) Viral DNA synthesis was delayed at the permissive temperature for as long as 8 h. Once initiated, it continued at 39 degrees C. (iv) Marker rescue of tsB7 by transfection with herpes simplex virus 1(F) DNA fragments localized the mutation to between 0.501 and 0.503 map units on the viral genome. These results are consistent with the tsB7 lesion being in a gene coding for a virion component which affects release of viral DNA from capsids and onset of viral DNA synthesis.