溶瘤病毒与肿瘤治疗

研究发现有些病毒具有特异性感染并杀伤肿瘤细胞的能力,这类病毒被称为“溶瘤病毒”。天然的溶瘤病毒有细小病毒、呼肠孤病毒、新城疫病毒、水疱性口炎病毒、麻疹病毒等。有些病毒缺失一些病毒基因的突变体,具有溶瘤病毒的特性,其中包括腺病毒、疱疹病毒和甲型流感病毒。通过病毒基因工程可以进一步提高溶瘤病毒的安全性和杀伤肿瘤细胞的效果。一系列体外、动物模型和临床的试验证实,不少溶瘤病毒具有良好的安全性和抑制肿瘤的能力。     

溶瘤病毒靶向治疗肿瘤的策略

近年来,随着国内外几款溶瘤病毒制剂的相继上市,溶瘤病毒疗法成为肿瘤免疫治疗的焦点。溶瘤病毒可选择性感染并裂解肿瘤细胞,同时释放肿瘤相关抗原激活机体的抗肿瘤免疫反应,达到杀伤肿瘤细胞和抑制肿瘤生长的目的。溶瘤病毒对肿瘤的靶向杀伤作用决定了其安全性和溶瘤效果。为了开发出安全高效的溶瘤病毒,目前主要采用以下策略：利用某些病毒载体对肿瘤细胞的天然靶向性,使溶瘤病毒选择性地在肿瘤细胞内复制并杀伤肿瘤细胞;或者对病毒基因组进行缺失和插入等修饰,通过靶向肿瘤细胞特异性表面受体、胞内信号通路或者肿瘤微环境等提高溶瘤病毒的肿瘤靶向性。其中,肿瘤微环境中的低氧状态、新血管生成以及免疫抑制状态等都可成为溶瘤病毒的靶点。而溶瘤病毒通过表达细胞因子和免疫检查点抑制剂,或者与CAR-T细胞联合作用,靶向调节肿瘤微环境中免疫抑制状态,成为提高溶瘤病毒肿瘤靶向性的常用方法。本文将对以上溶瘤病毒靶向治疗肿瘤策略的研究进展进行综述。     

成人T细胞白血病细胞靶向型水泡性口炎病毒的构建及应用

目前肿瘤治疗主要使用放疗、药物化疗,具有很大的毒、副作用,研发肿瘤靶向性药物是未来发展趋势.成人T细胞白血病(adult T cell leukemia,ATL)是一种由HTLV-1病毒引起的人恶性CD4 T淋巴细胞白血病,目前尚无有效治疗方法.溶瘤性水泡性口炎病毒(vesicular stomatitis virus,VSV)是一种肿瘤治疗病毒载体,利用HIV-1囊膜蛋白gp160对野生型VSV病毒进行假型化改造,研制了具备人CD4受体靶向性的重组VSV病毒(VSV-△G-gp160G),在对ATL病人肿瘤细胞进行的体外杀伤实验(ex vivo)中,显示出良好的应用前景.     

溶瘤痘苗病毒对肿瘤细胞作用机制的研究进展

溶瘤病毒治疗,是指利用具有复制能力的病毒选择性地感染和摧毁癌细胞,而对正常细胞或组织影响很少甚至没有影响的一种癌症治疗方法.痘苗病毒在肿瘤的基因治疗应用研究中以其独特的优势而备受关注.痘苗病毒感染细胞后具有产生病毒颗粒快、宿主范围广、基因组容量大、安全性高、传播高效等优点.尤为重要的是,基于溶瘤痘苗病毒的天然特性或遗传工程的改造,溶瘤痘苗病毒可以选择性地在肿瘤细胞中复制并对其产生杀伤效果.痘苗溶瘤病毒引起肿瘤细胞裂解和死亡是由多种不同的机制引起的.本文就近年来溶瘤痘苗病毒对细胞作用机制和相关信号通路的影响作一简要综述.     

重组水疱性口炎病毒的改造策略及在病毒学研究中的应用进展

水疱性口炎病毒（Vesicular stomatitis virus,VSV）是一种在家畜中流行,给畜牧业造成严重经济损失的病毒。然而,随着研究的深入,VSV不仅作为负链RNA病毒的代表种帮助阐明了负链RNA病毒的复制机制,并且随着通过cDNA克隆拯救VSV技术的建立,VSV成为了病毒学研究、疫苗研发及肿瘤治疗的有力工具。本文对VSV的基因组结构、增殖方式、重组VSV的构建技术以及重组VSV在基础研究和临床方面的应用进行了综述。     

溶瘤病毒载体研究进展

溶瘤病毒(oncolytic virus,OVs)疗法是治疗肿瘤的一种新方法,它可通过直接杀死肿瘤细胞并引起机体的免疫反应发挥作用.然而天然溶瘤病毒有一定的局限性,因此需将各种不同的病毒作为载体,通过基因修饰的方法增强或减弱病毒毒力并导入新的功能性基因,以提高其溶瘤作用.目前可以作为溶瘤病毒载体的有单纯疱疹病毒、腺病毒、牛痘病毒、水泡性口炎病毒、麻疹病毒、腮腺炎病毒、脊髓灰质炎病毒等.这些病毒载体均可通过不同的基因修饰方法,靶向性感染并杀死不同的肿瘤细胞,获得较好的溶瘤作用.本文综述了几种溶瘤病毒载体的基因修饰方法,以及修饰后的溶瘤效果.     

靶向宿主代谢重编程的溶瘤病毒调控策略

溶瘤病毒是一类天然的或经过基因编辑后能特异性在肿瘤细胞中复制、发挥抗肿瘤效应的病毒。溶瘤病毒的抗肿瘤效应主要通过以下两个方面实现：a. 直接的溶瘤效应，例如诱导肿瘤细胞发生凋亡、促使细胞裂解等；b. 溶瘤病毒作为一种激活免疫的药物，通过诱导机体产生强烈的抗肿瘤免疫，达到清除肿瘤的目的。溶瘤病毒疗法作为免疫疗法的一个重要分支，因其具有肿瘤特异性，便于基因改造等优点，成为该领域的研究热点。截至目前，处在临床实验招募和完成阶段的溶瘤病毒疗法虽然已达100多例，但已批准上市的产品仅有4款。溶瘤疗法应用于肿瘤治疗领域还面临着诸多挑战。因此，系统性回顾溶瘤病毒的改造策略，深入了解溶瘤病毒的生物学过程显得尤为必要。病毒依赖于宿主完成复制、增殖过程，其生物学过程与宿主的代谢状态密切相关。肿瘤的标志性特征为代谢重编程，即肿瘤细胞重新构建代谢网络以满足指数生长和增殖的需求并防止氧化应激的过程。通常包括糖酵解的增强和谷氨酰胺分解，以及线粒体功能和氧化还原稳态的变化。通过靶向宿主代谢重编程增强溶瘤病毒的复制、溶瘤能力是当前极具前景的方向。本文综述溶瘤病毒的临床应用现状及与代谢相关的调控机制，为进一步开发新型溶瘤病毒以及联用方式提供新的思路。     

溶瘤病毒联合CAR-T细胞治疗实体瘤研究进展

嵌合抗原受体修饰的T细胞(chimeric antigen receptor T cells, CAR-T)疗法属于肿瘤免疫治疗的范畴。该疗法在血液系统恶性肿瘤治疗中表现优异,但在实体瘤治疗中存在诸多挑战。近年来,溶瘤病毒(oncolytic viruses, OVs)在针对黑色素瘤、脑胶质瘤等实体瘤适应证的临床试验中展现出良好的疗效。溶瘤病毒一方面选择性地在肿瘤细胞中复制杀伤肿瘤细胞,另一方面通过激活机体自身的免疫系统发挥抗肿瘤作用。因此,溶瘤病毒与免疫检查点抑制剂、肿瘤浸润淋巴细胞疗法(tumor infiltrating lymphocytes, TIL)等免疫疗法的联合应用也在广泛开展。目前研究表明,溶瘤病毒不仅能够增加CAR-T细胞的抗肿瘤活性,而且通过传递肿瘤相关抗原或特异性抗原来增强CAR-T细胞对肿瘤的杀伤作用,同时溶瘤病毒还可以帮助CAR-T细胞克服免疫抑制性的肿瘤微环境。两种疗法的联合应用在临床前研究中展现出了良好的疗效和安全性,能够解决CAR-T在实体瘤治疗领域的瓶颈,具有广阔的临床转化前景。本文就溶瘤病毒与CAR-T细胞联合治疗实体瘤的药效及相关机制研究展开论述...     

溶瘤病毒联合小分子抑制剂应用于肿瘤治疗的研究进展

溶瘤病毒因具有选择性杀伤肿瘤细胞的特性,已成为目前较有前景的肿瘤治疗类药物。溶瘤病毒疗法的安全性和有效性在临床中已得到证实,但由于恶性肿瘤高度的异质性和复杂性使得溶瘤病毒单药治疗肿瘤的效果受限,因此溶瘤病毒联合其他肿瘤治疗药物一起协同治疗肿瘤将是未来肿瘤治疗的重要发展方向之一,有望为肿瘤的治疗带来新的突破。新近研究表明,不同的小分子抑制剂可通过多种机制控制肿瘤生长,其在体外协同溶瘤病毒能达到更优的肿瘤治疗效果。本文就目前溶瘤病毒联合小分子抑制剂治疗肿瘤的研究进展进行综述。     

溶瘤腺病毒治疗肿瘤的研究进展

溶瘤腺病毒是一种改造过的能够选择性地在肿瘤细胞中复制,并能够杀死肿瘤细胞的腺病毒,目前已经应用于肿瘤治疗中。但是因为肿瘤的复杂性以及高突变性,所以提高溶瘤腺病毒对肿瘤的有效性,选择性和安全性成为了主要的研究方向。能够在体内正常表达shRNA、细胞因子、自杀基因、基质修饰蛋白等治疗性基因的溶瘤腺病毒具有比单纯的溶瘤腺病毒更强的抗肿瘤活性。而具有肿瘤特异性启动子,尤其是双调控启动子的溶瘤腺病毒对肿瘤细胞具有更强的选择性杀伤作用。另外用脂质体、PEG聚合物、纳米颗粒、多肽等包裹的溶瘤腺病毒能够减少病毒的免疫原性以及对肝脏的毒性,增强了全身给药途径的抗肿瘤活性。特别是用PEG连上抗体、小肽、细胞因子和配体,能显著提高溶瘤腺病毒的选择性。因此,整合病毒载体与非病毒载体的优点并与免疫治疗相结合,是一个很有希望的提高病毒靶向治疗效果的策略。     

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.