转IE2基因荷瘤小鼠中ATF5功能影响的研究

利用转IE2基因小鼠荷瘤的方法,对肿瘤组织中ATF5转录激活因子进行定性和定量的检测,从而探究巨细胞病毒(HCMV)即刻早期蛋白IE86对ATF5功能的影响。通过鼠胶质瘤细胞GL261对转基因鼠进行荷瘤,采用RT-PCR和Western blot的方法,对荷瘤鼠的肿瘤组织中转录因子ATF5的表达量进行检测。采用RT-PCR和Western blot的方法检测荷瘤鼠肿瘤组织中转录因子ATF5的表达,结果显示,转IE2基因小鼠体内ATF5表达量较正常小鼠ATF5表达量高。ATF5在转IE2基因荷瘤鼠中呈现高表达状态,ATF5是一个与凋亡密切相关的转录因子,在凋亡、分化及发育等生理过程中发挥着重要作用。     

MCMV感染同种异型皮肤移植小鼠结肠炎模型的建立

利用小鼠巨细胞病毒(Murine cytomegalovirus,MCMV)感染同种异型皮肤移植小鼠,建立MCMV感染结肠炎症模型,从而为研究人类肠道疾病提供可靠的动物模型。采用鼻腔接种的方式感染同种异型皮肤移植的小鼠。①供体:C57BL/6雌鼠,18只;受体:BALB/c雌鼠,72只,鼠龄4～6周,体重14～20g/只;将C57BL/6小鼠的背部皮肤移植到BALB/c小鼠背部的移植床上,术后给BALB/c小鼠腹腔注射环孢素连续2周(12mg/kg.d)。②将移植后小鼠随机分组,每组24只,按接种病毒接种剂量分为104PFU组和105PFU组,同时设立阴性对照组,即鼻腔接种细胞悬液(1×106/mL)。每日观察动物排便情况及体重等总体情况变化;分别于病毒接种后第5、9、14和第21d取得小鼠结肠组织,通过组织病理学检测、原位杂交g、B RT-PCR、pp65免疫组化以及透射电镜的方法,观察检测小鼠结肠组织中MCMV与其组织病理变化之间的关联性。结果:在105PFU组中,小鼠出现厌食、嗜睡、活动能力明显下降,且发现该组小鼠的体重下降。在本研究中我们检验感染后第14d小鼠的结肠组织,发现感染组小鼠的近端结肠组织中粘膜层均变薄,同时其结构也被破坏;感染组小鼠的远端结肠组织中均出现淋巴样滤泡和粘膜层结构异常,其中105PFU组小鼠的结肠粘膜层的破坏得更严重;pp65免疫组化检验结果为MCMV蛋白阳性;原位杂交结果显示结肠组织中MCMV IE1基因阳性,MCMV gB基因RT PCR检测结果为阳性;透射电镜观察可见疱疹样病毒颗粒。而阴性对照组上述检测指标均为阴性。结果表明,在同种异型皮肤移植后小鼠鼻腔接种MC-MV,小鼠结肠发生了类似于人类结肠炎的病理变化。该结肠炎动物模型的建立将为进一步研究HCMV感染结肠的发病机理以及药物干预建立一个极为重要的平台。     

BD2增强巨细胞病毒DNA疫苗的免疫效果研究

表达巨细胞病毒(cytomegalovirus,CMV)即刻早期蛋白(IE-1)的DNA疫苗能抵抗巨细胞病毒的感染。β防御素2型(BD2)能激活未成熟的树突状细胞,调节机体免疫反应。以小鼠为动物模型,探讨小鼠BD2(m BD2)增强鼠巨细胞病毒(murine cytomegalovirus,MCMV)IE-1 DNA疫苗的佐剂效果。将表达IE-1的质粒(p IE-1)与表达m BD2的质粒(p BD2)混合免疫小鼠,2周后用致死量的同源MCMV攻击小鼠。通过检测发现,混合免疫p IE-1和p BD2的小鼠与单独免疫IE-1相比,血清中IE-1特异性抗体含量升高,脾脏CD8+T细胞所分泌的IFN-γ水平上升,小鼠体重丢失明显下降,病毒攻击后小鼠存活率也有所提高。这些结果表明,BD2可以作为一种分子佐剂增强IE-1 DNA疫苗的免疫效果。     

IL-12对巨细胞病毒DNA疫苗免疫增强作用的研究

白介素12(interleukin 12,IL-12)主要和细胞免疫应答有关,是免疫过程中重要的调节因子。本研究探讨IL-12对编码巨细胞病毒(cytomegalovirus,CMV)即刻早期基因IE1的DNA疫苗的免疫增强作用。将CMVIE1质粒DNA单独或与编码IL-12的质粒DNA共同免疫小鼠,然后用致死量病毒攻击小鼠。通过检测小鼠体内诱导的细胞免疫应答、小鼠的存活率、体重丢失率、器官中的病毒滴度等来评价IL-12对疫苗免疫的佐剂效果。结果显示,与单独疫苗免疫组相比,IE1 DNA联合IL-12 DNA免疫组能够在小鼠体内诱导更高的细胞免疫应答水平,同时能够降低器官中的病毒滴度,显著提高保护率,从而更好地抵抗病毒攻击。实验证明,IL-12能够作为巨细胞病毒IE1 DNA疫苗的佐剂,提高免疫保护效果。     

MCMV不同途径感染免疫缺损性小鼠体内效应的研究

通过血管注射、腹下注射、唾液腺注射等3种不同途径将野生型小鼠巨细胞病毒(murine cytomegalovirus,MCMV)感染免疫缺损型小鼠CM17 SCID(sevele combined immunodeficiency,严重免疫缺损综合症),在感染后不同的时间内分别取唾液腺、脾、肝、肺和肾脏测定其病毒滴度,以及测定感染后SCID小鼠的死亡率．同时通过唾液腺注射RvM43突变株,测定病毒在唾液腺中的滴度．结果显示：经尾部血管途径注射的体内唾液腺、肺、脾、肝和肾脏的病毒滴度高峰期和SCID小鼠死亡时间均显著性早于经腹下注射、唾液腺注射途径、除唾液腺器官外,经唾液腺注射途径肺、脾、肝和肾脏的病毒的出现时间晚于经尾部血管和腹下注射途径．经唾液腺注射后,唾液腺中突变型RvM43在各时间点的病毒滴度及高峰出现时间与野生型相同．由此可知,从唾液腺感染小鼠后：MCMV病毒在唾液腺中的生长不受M43基因突变的影响,小鼠巨细胞病毒不同途径感染免疫缺损型小鼠CMl7 SCID的体内生物学效应有差异．因此有必要通过不同途径感染宿主来研究MCMV基因的体内功能．     

GATA-1/2对感染HCMV人单核细胞中病毒LUNA基因转录的影响

该文通过建立人巨细胞病毒(human cytomegalovirus,HCMV)感染人单核白血病细胞(THP-1)的潜伏和激活细胞模型,研究转录因子GATA-1/2与HCMV LUNA(latency unique nuclear antigen)基因转录的关系。采用免疫印迹(Western blot)技术检测HCMV潜伏和激活感染组GATA-1/2蛋白质水平;染色质免疫共沉淀(chromatin immnuoprecipitation,Ch IP)技术检测GATA-1/2与LUNA基因5′上游序列结合情况;采用sh RNA干扰技术敲低THP-1细胞中GATA-1/2的表达后,检测潜伏和激活感染组HCMV LUNA基因m RNA水平。结果表明,HCMV潜伏感染组LUNA基因m RNA及GATA-1/2蛋白质水平均高于激活感染组,差异有显著统计学意义(P0.01);HCMV潜伏感染组转录因子GATA-1/2与LUNA基因5′启动子区域结合率低于激活感染组,差异有显著统计学意义(P0.01);sh RNA干扰技术敲低THP-1细胞GATA-1/2后,HCMV LUNA基因m RNA水平出现下调。研究结果表明,转录因子GATA-1/2在HCMV潜伏和激活感染THP-1细胞时与LUNA基因5′上游启动子区域存在结合,并与LUNA基因的表达有关。     

人巨细胞病毒潜伏感染机制的研究进展

人巨细胞病毒可通过原发感染或者潜伏感染再激活而广泛传播.基于对人巨细胞病毒AD169株和Towne株基因测序的完成,以及人巨细胞病毒的基因功能研究及其相关动物模型如小鼠模型、猪模型、恒河猴模型等的研究,人巨细胞病毒感染的潜伏机制研究取得了一定进展.本文从人巨细胞病毒的感染机制、免疫应答和免疫逃避三方面对人巨细胞病毒潜伏感染机制的研究现状进行简要综述.     

脂多糖LPS诱导的神经炎症对小鼠认知功能的影响及相关机制分析

为研究脂多糖(lipopolysaccharide,LPS)对小鼠认知功能的影响,本研究将18只C57BL/6小鼠随机分为两组,即正常对照组和LPS处理组,每组各9只小鼠。在腹腔注射LPS 24 h后行水迷宫实验检测小鼠行为学变化。此外,本研究采用Western blotting和免疫组化检测小鼠脑内小胶质细胞特异性标记物离子通道相关钙衔接蛋白(ionized calcium binding adapter,IBA1)的表达,TUNEL凋亡法检测小鼠脑内神经元凋亡情况。实验结果发现LPS处理后小鼠认知功能下降。Western blotting和免疫组化结果均提示LPS处理后小鼠脑中IBA1表达量增加,小胶质细胞激活;TUNEL提示LPS处理后小鼠脑内出现大量凋亡神经元,由此推断LPS可能通过激活小胶质细胞,扩大神经炎症反应,增加神经元凋亡导致小鼠认知功能下降。     

鼠巨细胞病毒 IE-1核酸疫苗和灭活疫苗联合免疫抗病毒感染的研究

巨细胞病毒（Cytomegalovirus,CMV）在人群中感染普遍,对婴幼儿及免疫低下人群中造成严重疾病,目前还没有针对该病毒的商品化疫苗。本研究以BALB/c小鼠为动物模型,探讨鼠巨细胞病毒（Murine cytomega-lovirus,MCMV）IE-1 DNA疫苗和MCMV灭活疫苗联合免疫抗MCMV感染的免疫保护效果。将编码IE-1基因的DNA疫苗（pIE-1）通过肌肉注射辅以电穿孔的方式对小鼠进行初免,再用全病毒灭活疫苗单独或者辅以MF59佐剂进行加强免疫,分别通过ELISA和ELISPOT方法检测到联合免疫策略在免疫组小鼠体内诱导了MC-MV特异性的抗体应答和CTL应答;免疫两周后用3＆#215;LD50致死剂量MCMV感染小鼠,疫苗对小鼠的免疫保护通过检测小鼠存活率、重要器官中的病毒滴度及体重丢失率来评价。结果显示,与单独免疫DNA疫苗或灭活疫苗相比,IE-1 DNA疫苗联合灭活疫苗组能同时在小鼠体内诱导体液免疫和细胞免疫应答,并提供小鼠完全保护;而且MF59辅以灭活疫苗免疫小鼠能增强疫苗的免疫效果。     

黄芩苷对巨细胞病毒神经系统感染小鼠学习记忆功能及海马中细胞凋亡的调节作用

新生儿感染巨细胞病毒(Cytomegalovirus,CMV)能够引起中枢神经系统不可逆损害,遗留神经功能缺损,危害较大,但缺乏有效的防治手段。黄芩苷是中药材黄芩中的黄酮类活性物质,具有抗凋亡、抗氧化、抗炎等功能,对新生大鼠缺血缺氧性脑损伤具有保护作用。基于此,本研究将黄芩苷用于小鼠巨细胞病毒(Mouse cytomegalovirus,MCMV)感染新生KM小鼠的干预,并探究黄芩苷对MCMV感染后中枢神经损害的保护作用。为研究黄芩苷对MCMV神经系统感染小鼠学习记忆功能及海马中细胞凋亡的调节作用,本研究将新生KM小鼠随机分为对照组、MCMV组、黄芩苷组、黄芩苷+U0126组,后三组腹腔注射MCMV病毒悬液以获得MCMV神经系统感染模型,MCMV组给予生理盐水灌胃,黄芩苷组给予黄芩苷灌胃,黄芩苷+U0126组则给予黄芩苷灌胃及U0126腹腔注射。比较四组学习记忆功能指标及海马组织中MCMV载量、细胞凋亡率、凋亡基因表达量、信号通路基因表达量。结果显示:与对照组比较,MCMV组小鼠的逃避潜伏期明显延长(P0.05),穿平台次数明显减少(P0.05),海马组织中MCMV-DNA载量、细胞凋亡率及bax、cleaved-caspase-3的表达量明显增加(P0.05),海马组织中bcl-2、p-MEK1、p-ERK1/2的表达量明显降低(P0.05);与MCMV组小鼠比较,黄芩苷组小鼠的逃避潜伏期明显缩短(P0.05),穿平台次数明显增多(P0.05),海马组织中MCMV-DNA载量无明显变化(P0.05),海马组织的细胞凋亡率及bax、cleaved-caspase-3的表达量明显降低(P0.05),海马组织中bcl-2、p-MEK1、pERK1/2的表达量明显增加(P0.05);与黄芩苷组比较,黄芩苷+U0126组小鼠的逃避潜伏期明显延长(P0.05),穿平台次数明显减少(P0.05),海马组织中MCMV-DNA载量无明显变化(P0.05),海马组织的细胞凋亡率及bax、cleaved-caspase-3的表达量明显增加(P0.05),海马组织中bcl-2、p-MEK1、p-ERK1/2的表达量明显降低(P0.05)。综上,黄芩苷能够改善MCMV神经系统感染小鼠的学习记忆功能,通过激活MEK1/ERK1/2途径抑制海马中细胞凋亡是其可能的分子机制。     

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.