巨细胞病毒感染对细胞肾素基因表达的影响及其生物学意义

目的 探讨巨细胞病毒(cytomegalovirus,CMV)感染肾球旁细胞肾素基因表达的变化及其意义.方法 用病毒感染复数(MOI)为10、0.1和0的鼠CMV分别与鼠肾球旁细胞模型As4.1细胞共育5 d作为实验组;用紫外线灭活病毒的假感染(mock感染)对照组.RT-PCR检测感染细胞中CMV即刻早期基因1(IE1)的表达;免疫荧光观察肾素阳性细胞和肾素阳性颗粒在细胞的分布;双色免疫荧光染色观察肾素阳性颗粒是否出现在CMV阳性细胞;RT-PCR和Western blot检测肾素基因在感染细胞内的表达.结果 CMV感染As4.1细胞后出现典型的病毒空斑;病毒感染细胞CMV IE1 RT-PCR产物阳性;肾素阳性细胞集中在病毒空斑周围CMV新感染细胞区,肾素阳性荧光颗粒主要以块状和环状存在于病毒感染细胞质中;双色免疫荧光染色显示肾素阳性颗粒和CMV阳性颗粒出现在同一细胞;CMV感染细胞肾素基因的表达随病毒感染量增加而增加.结论 CMV感染并导致其宿主细胞肾素基因表达,可能涉及CMV加速心血管疾病发生发展的新机制.     

人巨细胞病毒感染对宿主细胞凋亡影响的研究进展

人巨细胞病毒（HCMV）属B疱疹病毒亚科，在人群中普遍感染。研究表明HCMV感染导致临床病症与细胞凋亡有密切关系，HCMV感染与细胞凋亡关系具有多样性和复杂性，在不同的阶段表现为不同的作用。研究HCMV与细胞凋亡的关系不仅有助于阐明HCMV感染细胞及细胞对其反应的分子机制和研发新的抗病毒制剂，而且能为HCMV引起临床疾病的治疗提供新的方案。     

巨细胞病毒感染时免疫功能的变化及其意义

目的　探讨巨细胞病毒感染时免疫变化及其意义。方法　以 2 0名CMV IgM(Cytomegalovirus immunoglobulinM)阳性的病儿为观察对象 ,另设对照组 30例。ELISA法检测柯萨奇B组病毒抗原 (CVB Ag)、IgM抗体 (CVB IgM)、巨细胞病毒IgM抗体 (CMV IgM)、EB病毒IgM抗体 (EBV IgM) ,单克隆抗体标记间接ABC免疫法检测外周血T细胞亚群。结果　CMV感染组的LAK细胞、NK细胞活性均明显降低 (P <0 .0 1)。合并其它感染原的CMV混合感染组CD3含量减少 ,CD8含量增加 (P <0 .0 5 ) ,CD4 CD8数值明显降低 (P <0 .0 1)。病毒混合感染并合并支原体感染组CD3含量减少 (P <0 .0 5 )、CD4 CD8数值、IgA含量明显降低 (P <0 .0 1)。结论　巨细胞病毒感染影响了T细胞亚群的平衡 ,在合并其他感染时天然免疫细胞功能下降和T细胞亚群紊乱更明显     

人巨细胞病毒感染对宿主细胞凋亡影响的研究进展

人巨细胞病毒(HCMV)属β疱疹病毒亚科,在人群中普遍感染。研究表明HCMV感染导致临床病症与细胞凋亡有密切关系,HCMV感染与细胞凋亡关系具有多样性和复杂性,在不同的阶段表现为不同的作用。研究HCMV与细胞凋亡的关系不仅有助于阐明HCMV感染细胞及细胞对其反应的分子机制和研发新的抗病毒制剂,而且能为HCMV引起临床疾病的治疗提供新的方案。     

巨细胞病毒感染对造血功能影响的研究进展

人巨细胞病毒(HCMV)是人群中广泛存在的感染因子，随着免疫力低下人群(器官移植、恶性肿瘤、艾滋病等)的增加，近10年来，HCMV感染引起严重疾病的机制再次成为医学领域的研究热点，HCMV几乎可感染人体所有组织，整个造血系统尤其是造血祖细胞是HCMV的主要潜伏部位。通过抑制细胞免疫、诱导细胞凋亡，逃避吞噬细胞溶酶体的降解而早潜伏性感染，经过转移活化刺激、细胞分化和细胞因子等作用再激活，造血系统经常受累，其中骨髓抑制、血小板减少和免疫功能紊乱较常见。     

人巨细胞病毒感染对小鼠脑组织同源盒基因表达的影响

目的研究小鼠脑组织同源盒基因（homeobox gene，Hox）的表达状态及人类巨细胞病毒（human cytomegalovims，HCMV）感染对小鼠脑组织Hox基因表达的影响，以探讨HCMV致畸的分子机制。方法昆明系小鼠48只，随机分为实验对照组（16只）和病毒感染组（32只），病毒感染为脑内注射。在感染后7、15、30、60d分别以病理学方法观察病理损伤，以免疫组化方法检查HCMV—LA（1ateantigen），PCR检测小鼠脑组织中HCMV—DNA。在建立HCMV脑部感染的小鼠模型基础上，用RT-PCR测定Hox基因在病毒感染组和实验对照组小鼠脑组织中的表达,并用同位素标记的cDNA探针进行Northern-blot检测相应的表达状况。结果（1）接种HCMVAD169株的小鼠脑组织发生了病理改变，免疫组化和PCR方法在神经细胞内查到了HCMV-LA和DNA；（2）RT-PCR和Northern-blot发现：对照组的小鼠脑组织表达Hox-A9、Hox-A11、Hox-A12和Hox-A13，但不表达Hox-B13；HCMV感染后，小鼠脑组织被诱导表达Hox-B13，与对照组比较差异有统计学意义（P〈0.01），且于感染后的30d达到高峰，而Hox—A9、Hox—A11的表达下调（P〈0.05）；Hox—A10和Hox—A13的表达增强。结论HCMVAD169株可感染小鼠神经系统。HCMV感染可诱导小鼠神经系统发育基因Hox表达改变，这对研究HCMV感染致畸的分子机制提供了有价值的理论依据。     

人巨细胞病毒感染对小鼠脑组织同源框基因表达的影响

目的　研究小鼠脑组织同源框基因 (homeoboxgene ,Hox)的表达状态及人巨细胞病毒(humancytomegalovirus ,HCMV)感染对小鼠脑组织Hox基因表达的影响 ,以探讨HCMV致畸的分子机制。方法　昆明系小鼠 4 8只 ,随机分为 :实验对照组 (16只 )和病毒感染组 (32只 ) ,病毒感染为脑内注射。在感染后 7、15、30、6 0d分别以病理学方法观察病理损伤 ,以免疫组化方法检查HCMV LA(latean tigen) ,PCR检测小鼠脑组织中HCMV DNA。在建立HCMV脑部感染的小鼠模型基础上 ,用RT PCR测定Hox基因在病毒感染组和实验对照组小鼠脑组织中的表达 ,并用同位素标记的Hox寡核苷酸探针进行Northernblot检测相应的表达状况。结果　 (1)接种HCMVAD16 9株的小鼠脑组织发生了病理改变 ,免疫组化和PCR方法在神经细胞内查到了HCMV LA和DNA ;(2 )RT PCR和Northernblot发现 :对照组的小鼠脑组织表达Hoxa2、Hoxb1和Hoxb2 ,但不表达Hoxb5、Hoxb8;HCMV感染后 ,小鼠脑组织被诱导表达Hoxa1,与对照组比较差异有显著性意义 (P <0 .0 1) ,且于感染后的 15d达到高峰 ,而Hoxb1的表达下调 (P <0 .0 5 ) ;Hoxa2和Hoxb2无明显变化 ;Hoxb5和Hoxb8仍旧不表达。结论　HCMVAD16 9株可感染小鼠神经系统。HCMV感染可诱导小鼠神经系统发育基因Hox基因表达改变 ,这对     

树突状细胞在人巨细胞病毒感染中的作用

人巨细胞病毒(human cytomegalovirus,HCMV)在人群中感染率极高,通过多种免疫逃避机制,实现在宿主体内的长期潜伏感染。树突状细胞(dendritic cells,DC)是重要的抗原提呈细胞,在诱导和维持特异性免疫应答中发挥重要的作用。人体内的DC根据来源、表型分为两群:髓系DC(myeloid DC,mDC)和浆细胞样DC(plasmacytoid DC,pDC),大量研究证实HCMV介导的多种免疫逃避机制中,部分是通过影响DC功能实现的。HCMV不仅可以感染mDC,影响mDC表型、迁移、分泌细胞因子、激活T细胞功能,而且还可以抑制pDC分泌干扰素水平及激活T细胞能力,并且激活过度的B细胞反应,导致机体抗病毒细胞免疫反应的抑制和体液免疫紊乱,实现病毒长期潜伏感染。本文主要讨论HCMV是如何改变两种DC亚型的功能以实现免疫逃避目的。     

巨细胞病毒感染与细胞凋亡的研究进展

CMV病毒和细胞凋亡的关系相当复杂，有时表现为诱导凋亡作用，有时表现为抗凋亡作用。从病毒的角度看，病毒诱导小胶质细胞、巨噬细胞、造血干细胞、中性粒细胞及淋巴细胞等发生凋亡，可干扰机体抗病毒免疫反应，使病毒不至于被机体免疫系统消除，对于病毒感染的有些宿主细胞，病毒则利用自身抗凋亡作用以利于在感染细胞内完成病毒的复制和生活周期。从宿主的角度出发，机体会调动全身和局部抗病毒免疫反应、宿主细胞会启动凋亡机制来清除病毒。     

巨细胞病毒对骨髓基质细胞粘附功能的影响

目的:探讨巨细胞病毒(CMV)对骨髓基质细胞表面粘附分子ICAM-1 和VCAM-1的表达及骨髓基质细胞对正常造血细胞的粘附率的影响。方法:用流式细胞仪检测骨髓基质细胞表达粘附分子ICAM-1和VCAM-1阳性率,用MTT方法检测骨髓基质细胞对正常骨髓造血细胞的粘附率。结果:本实验所用的CMV可以感染骨髓基质成纤维细胞;100TCID₅₀剂量以下CMV对骨髓基质细胞无明显破坏作用;活性CMV 感染骨髓基质细胞早期(18 h)粘附分子ICAM-1表达明显较高,晚期(120 h)ICAM-1表达明显较低;灭活的CMV也能使骨髓基质细胞ICAM-1表达增高,作用与有活性的CMV相似;骨髓基质细胞在CMV感染早期,对造血细胞的粘附率增高。CMV对VCAM-1的表达无明显影响。结论:CMV 感染骨髓基质细胞早期,骨髓基质细胞对造血细胞粘附能力增高,CMV感染晚期骨髓基质细胞对造血细胞粘附能力降低。     

Nitric oxide induces metallothionein-I gene expression in mesangial cells

In various forms of injury involving the renal glomerulus, mesangial cells are exposed to potentially toxic concentrations of nitric oxide (NO) caused by activation of the inducible isoform of nitric oxide synthase (NOS). Whether mesangial cells possess systems that can defend against NO mediated oxidative injury is unknown. One putative system is Metallothionein (MT). Metallothioneins constitute a family of cysteine proteins and play a significant role as anti-oxidants. The authors assessed whether NO upregulates MT-I expression in cultured glomerular mesangial cells. Northern blot analysis revealed that steady state MT-I mRNA levels were increased by three different NO donors: sodium nitroprusside (SNP), S-nitroso-N-acetyl-DL-penicillamine (SNAP), and Spermine-NONOate (Sper/NO). The increase in MT-I mRNA levels induced by SNAP-derived NO was attenuated by the antioxidant N-acetylcysteine (NAC), a glutathione (GSH) precursor, which indicates that the mechanism of NO-mediated MT-I expression may involve an oxidative stress response. These observations identify MT-I as a putative antioxidant system in NO-mediated mesangial cell injury.     

Interleukin-1 inhibits renin gene expression in As4.1 cells but not in native juxtaglomerular cells

 Cardiovascular effects of inflammatory interleukins (IL) have been suggested to be mediated by the renin-angiotensin system in vivo. To address the direct cellular effect of IL, we examined the influence of IL-1β on renin secretion and renin mRNA in cultures of mouse juxtaglomerular granular (JG) cells and in the mouse tumor cell line As4.1, which expresses renin mRNA. Renin mRNA levels and secretion of active renin were not significantly changed by IL-1β in native JG cells. Activation of adenylyl cyclase by forskolin increased renin secretion and renin mRNA levels three- and fivefold, respectively. These stimulatory responses to forskolin were not altered by IL-1β. In contrast to native JG cells, renin mRNA abundance was markedly suppressed by IL-1β in As4.1 cells, whereas secretion of active renin and the stability of renin mRNA were not changed. In As4.1 cells forskolin did not change renin secretion or renin mRNA abundance in the absence or in the presence of IL-1β. These findings suggest that IL-1β has no direct influence on renin secretion and renin mRNA abundance at the level of native JG cells. Received: 15 December 1997 / Received after revision: 25 April 1998 / Accepted: 27 May 1998     

Vesicular stomatitis virus infects resident cells of the central nervous system and induces replication-dependent inflammatory responses

Vesicular stomatitis virus (VSV) infection of mice via intranasal administration results in a severe encephalitis with rapid activation and proliferation of microglia and astrocytes. We have recently shown that these glial cells express RIG-I and MDA5, cytosolic pattern recognition receptors for viral RNA. However, it is unclear whether VSV can replicate in glial cells or if such replication is required for their inflammatory responses. Here we demonstrate that primary microglia and astrocytes are permissive for VSV infection and limited productive replication. Importantly, we show that viral replication is required for robust inflammatory mediator production by these cells. Finally, we have confirmed that in vivo VSV administration can result in viral infection of glial cells in situ. These results suggest that viral replication within resident glial cells might play an important role in CNS inflammation following infection with VSV and possibly other neurotropic nonsegmented negative-strand RNA viruses.     

Internalization of Staphylococcus aureus by endothelial cells induces cytokine gene expression.

The ability of the vascular endothelium to elaborate cytokines in response to gram-positive sepsis has received limited attention. This study examined cytokine expression by human umbilical vein endothelial cells (EC) following infection with a gram-positive bacterial pathogen, Staphylococcus aureus. S. aureus infection of EC resulted in the production of interleukin-6 (IL-6) and IL-1 beta. For IL-6, message was detected at 3 h after infection, protein was present at 24 h, and both message and protein persisted for 72 h. IL-1 beta message was detected at 12 h, IL-1 beta protein was detected at 24 h, and both persisted for 72 h. Message for colony-stimulating factor 1 remained unaltered. UV-killed S. aureus also elicited IL-1 beta and IL-6 message and protein expression at 24 and 48 h. Twenty-one clinical isolates of S. aureus were tested, and all induced IL-6 release by 48 h. However, the laboratory strain 8325-4 did not induce cytokine expression at any time point and was internalized by EC 1,000-fold less than other strains were. Internalization of latex beads by EC did not induce IL-6 gene expression. Furthermore, cytochalasin D treatment of the EC prevented IL-1 and IL-6 induction by S. aureus but not by tumor necrosis factor alpha or lipopolysaccharide. These results indicate that S. aureus is a potent inducer of IL-1 and IL-6 in EC and that internalization of S. aureus by EC is necessary for their cytokine expression. Thus, our data suggest that the vascular endothelium may play an important role in the pathogenesis of septicemia caused by gram-positive organisms.