呼肠孤病毒与SARS相关的形态学依据

SARS患者病理尸检肺组织样品分离病毒出现细胞病变的Hep2 培养细胞,按常规制作超薄切片,透射电镜下观察。电镜下,检出在感染细胞内复制、组装的呼肠孤病毒及其包涵体。病毒粒子衣壳立体对称、无包膜、直径在60~80nm。成熟病毒粒子核心致密常排列呈晶格状,不成熟病毒粒子核心空亮。数目不等的上述两种病毒粒子、长短不等的微管样结构和病毒浆常在核旁胞质内组成大小不等、无定形的病毒包涵体。此发现进一步提供了呼肠孤病毒感染有可能与SARS相关的形态学依据。     

呼肠孤病毒与SARS相关的形态学依据

SARS患者病理尸检肺组织样品分离病毒出现细胞病变的Hep2培养细胞,按常规制作超薄切片,透射电镜下观察.电镜下,检出在感染细胞内复制、组装的呼肠孤病毒及其包涵体.病毒粒子衣壳立体对称、无包膜、直径在60～80nm.成熟病毒粒子核心致密常排列呈晶格状,不成熟病毒粒子核心空亮.数目不等的上述两种病毒粒子、长短不等的微管样结构和病毒浆常在核旁胞质内组成大小不等、无定形的病毒包涵体.此发现进一步提供了呼肠孤病毒感染有可能与SARS相关的形态学依据.     

对虾杆状病毒感染螃蟹组织的电镜观察

应用电子显微技术对人工养殖对虾池内的感病螃蟹作了组织切片的电镜观察,发现肝脏、胃、肠组织细胞核内和肌纤维间质中有大量杆状病毒,电镜下的病毒粒子的形态、大小与在中国对虾体内观察到的无病毒包涵体杆状病毒一致。     

意大利蝗痘病毒一些特性研究

电镜观察意大利蝗痘病毒的包涵体大多数为椭圆形,少数为近圆形,大小相差极为悬殊。病毒粒子呈卵圆形,表面桑椹状。病毒粒子髓核呈圆筒状,其纵切面内绳索结构折叠2—3次,横切面可以看到2—3个圆点,侧体也圆筒状,均匀包围在核衣壳外面。DNA经限制性内切酶LoR I酶切产生16个DNA片段,据此求得DNA分子量为135.7×106D。 意大利蝗痘病毒包涵体的裂解释放病毒速度快,在相同条件下比亚洲小车蝗痘病毒包涵体裂解释放病毒粒子快。当温度恒定(37℃),在一定的pH值内(pH 9.0—11.5),随pH值的升高包涵体裂解释放病毒粒子速度加快。当pH值恒定(11.2),在一定的温度范围内(25～40℃),随温度的升高包涵体的裂解释放病毒粒子速度加快。     

斜带髭鲷外周血嗜中性粒细胞核内包涵体的超微结构

目的在对斜带髭鲷（Hapalogenys nitens）外周血细胞结构进行透射电镜观察时发现嗜中性粒细胞存在大量的核内包涵体,系统研究了这些核内包涵体的超微结构,以探讨其来源和形成过程。方法应用电镜技术对这些核内包涵体的超微结构进行研究。结果斜带髭鲷外周血嗜中性粒细胞的核内包涵体可分为假包涵体和真包涵体两种类型,包涵体中的内含物来自胞质。胞核首先是以核膜内陷的方式将胞质及其各种有形成分包绕进核内而在核质外层形成具有双层膜包裹的典型假包涵体,随后假包涵体双层膜降解消失而转化成无被膜包裹的真包涵体,即核内糖原包涵体。结论假包涵体是形成真包涵体的开始阶段。随着假包涵体向真包涵体的转变,包涵体内含物的组成及其超微结构也出现了显著变化。     

杆状病毒出芽病毒粒子膜融合蛋白的研究进展

杆状病毒是一类感染节肢动物的病原微生物,其基因组为双链环状DNA,大小为80～180kb。杆状病毒科包括核多角体病毒属(Nucleopolyhedrovirus,NPV)和颗粒体病毒属(Granulovirus,GV),其中NPV根据病毒粒子在包膜中的粒子数目不同而划分为多核衣壳核多角体病毒(multiple nucleocapsid     

病毒包涵体在病毒感染细胞中的作用

病毒包涵体(viral inclusion bodies,IBs)是病毒蛋白在胞质或核内的聚集体,许多病毒能够形成病毒包涵体。早期研究认为,病毒包涵体只是病毒复制及组装的重要起始位点,然而最近研究发现,一些病毒形成的病毒包涵体在宿主细胞抗病毒免疫反应中具有一定作用。本文主要就病毒包涵体在病毒感染细胞中的作用进行综述。     

发热伴血小板减少综合征病毒感染人源巨噬细胞形成包涵体结构

发热伴血小板减少综合征病毒(Severe fever with thrombocytopenia syndrome virus,SFTSV)是在我国首次发现的布尼亚病毒科白蛉病毒属的一种新型病毒,是新发传染病发热伴血小板减少综合征的致病病原。本研究通过免疫荧光共聚焦实验观察不同感染剂量和不同感染时相SFTSV核衣壳蛋白(Nucleocapsid protein,NP)在THP-1细胞内的动态定位特点,并应用电镜方法在超微结构水平观察不同感染时相THP-1细胞的胞内形态结构特征,发现SFTSV感染THP-1在胞内形成包涵体结构。研究进一步显示感染后的第3天核衣壳蛋白NP所形成包涵体的形态大小与感染后第7天培养上清中的病毒载量之间存在相关。本研究揭示SFTSV感染人源巨噬细胞THP-1形成的包涵体结构可能是SFTSV利用宿主细胞形成的特殊胞内结构以利于大量合成和产生新的病毒颗粒。     

杆状病毒核衣壳组装相关蛋白研究进展

杆状病毒生命周期中会产生包埋型和芽生型两种病毒粒子,这两种病毒粒子的包膜组成存在明显的差异,但拥有相同的核衣壳结构.杆状病毒核衣壳是由衣壳蛋白和杆状病毒基因组两部分组成,核衣壳的正常组装对两种病毒粒子的形成都是不可或缺的,因此核衣壳的正常组装在病毒的整个感染传播过程中发挥着重要作用.尽管越来越多参与核衣壳组装的蛋白被鉴定出来,目前还有许多核衣壳组装细节不明了,例如这些衣壳蛋白之间的互作关系是怎样的,宿主通过何种方式参与到病毒核衣壳组装过程等.本文主要以杆状病毒模式物种苜蓿银纹夜蛾核型多角体病毒(Autographa californica multiple nucleopolyhedrovirus,AcMNPV)为例综述了参与杆状病毒核衣壳组装的相关蛋白,并对一些参与核衣壳运输有关的核衣壳蛋白也做了阐述.     

杆状病毒生态学研究进展

杆状病毒是一类寄生于鳞翅目、膜翅目和双翅目昆虫及其它节肢动物的病原体,是具有囊膜的双链环状DNA病毒.目前至少已从600多种昆虫中发现有杆状病毒的感染,其中一部分能够引起宿主种群不同程度的流行病.杆状病毒在分类上独立为杆状病毒科,其典型的结构特征是病毒粒子包埋于蛋白质基质的包涵体中.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.