HCMV infection downregulates nidogen 1 and myelin protein zero

HCMV 感染下调 nidogen 1 和髓磷脂蛋白 0

• 批准号: 9982196
• 负责人: ELIZABETH A FORTUNATO
• 金额: $ 36.22万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-08 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9982196
• 关键词: 1q23; 1q42; 3-Dimensional; Affect; Automobile Driving; Basement membrane; Biological Assay; Biological Models; Birth; Blindness; Blood Vessels; Brain; CCCTC-binding factor; Cells; Child; Chromosomal Breaks; Chromosome 1; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Congenital Abnormality; Cytomegalovirus; Defect; Development; Disease; Down-Regulation; Endothelial Cells; Extracellular Matrix; Family; Fostering; Gene Silencing; Genetic Transcription; Goals; Human; Immune response; In Vitro; Infant; Infection; Link; Lytic Phase; Maps; Mental Retardation; Microcephaly; Morphogenesis; Mutation; Myelin P0 Protein; Nerve Sheaths; Neurons; Newborn Infant; Organism; Parents; Pathway interactions; Peripheral Nervous System; Play; Pregnancy; Prevention; Proteins; Regulation; Reporting; Research; Role; Schwann Cells; Sensorineural Hearing Loss; Site; Source; System; Testing; Time; Tissue Sample; Tissues; Translating; Viral; Viral Proteins; Virus; Virus Diseases; combat; congenital infection; early childhood; experimental study; extracellular; knock-down; migration; nerve stem cell; neural network; nidogen-1; optic cup; prevent; promoter; protein degradation; protein expression; tissue culture

The cellular dynamics responsible for induction of birth defects following Human Cytomegalovirus (HCMV) congenital infections are unclear. Annually, 1% of newborns are congenitally infected with HCMV. Five to 10% of these infants are symptomatic at birth, displaying a broad spectrum of central and peripheral nervous system (CNS and PNS) disorders including microcephaly, mental retardation, and sensorineural hearing loss (SNHL). The most severe manifestations may be due to lytic infection of neural progenitor cells (NPCs), as seen in tissue culture. The improper/abnormal differentiation of infected NPCs and neurons may also contribute to birth defects. The host immune response to HCMV infection may impact delicate CNS and PNS tissues during gestation. However, the development of SNHL during early childhood in infants asymptomatic at birth is perplexing. For the thousands of children and their families affected annually there is a critical need to determine the source of HCMV-induced birth defects to aid in their prevention and treatment. Our long term goal is to translate our in vitro tissue culture findings into elucidating HCMV's cellular interactions contributory to HCMV-induced birth defects. Our objective in this proposal is to determine if HCMV's specific interactions at two chromosome 1 loci, and the resulting downregulation of nidogen 1 (NID1) at 1q42 and myelin protein zero (MPZ) at 1q23, promote malfunctions in the CNS and PNS. We find expression of both proteins is downregulated in infected clinical tissue samples. NID1 is essential to the developing brain for neuronal migration and neural network excitability and plasticity. We find expressed NID1 protein is actively degraded post infection. Expression of the HCMV tegument protein pp71 induces breaks at both sites and downregulates NID1. pp71 and the insulator protein CTCF are bound at the 1q42 breaksite and the NID1 promoter. NID1 protein levels are also reduced after infection with a pp71 deletion virus (AD169del71), indicating at least one additional viral protein regulates NID1. HCMV targets NID1 with two viral proteins via two pathways suggesting NID1's elimination delivers strong selective advantage to the virus. MPZ is the principal nerve sheath protein of the PNS. Mutations in MPZ are causally linked to late onset SNHL. MPZ expression being limited solely to Schwann cells of the PNS, which seems unlikely could offer any selective advantage to the virus, is strong evidence that MPZ regulation is off-target. Deficiencies in NID1 and MPZ could have severe ramifications during development. We hypothesize HCMV specifically downregulates NID1 to promote dispersal of infected cells via remodeling of the extracellular matrix in infected blood vessels and that similarity in sequence shared between the 1q42 and1q23 sites leads to an off-target interaction with the 1q23 locus, downregulating MPZ, potentially leading to SNHL. We will determine 1) how HCMV downregulates NID1, 2) the benefit HCMV derives from this downregulation, 3) if MPZ is regulated in the same manner and 4) what are the ramifications of NID and MPZ downregulation?

人巨细胞病毒（HCMV）致出生缺陷的细胞动力学研究 先天性感染尚不清楚。每年有1%的新生儿先天性感染HCMV。五到 这些婴儿中有10%在出生时就有症状，表现出广泛的中枢和外周神经系统损害。 神经系统（CNS和PNS）疾病，包括小头畸形、精神发育迟滞和感觉神经性 听力损失（SNHL）。最严重的表现可能是由于溶解性感染的神经祖细胞 （NPC），如在组织培养中所见。感染的NPC和神经元的不适当/异常分化可能 也会导致出生缺陷。宿主对HCMV感染的免疫反应可能影响脆弱的CNS 和PNS组织。然而，SNHL在婴儿早期的发展 出生时无症状是令人困惑的。对于每年受影响的数千名儿童及其家庭来说， 迫切需要确定HCMV引起的出生缺陷的来源，以帮助预防， 治疗我们的长期目标是将我们在体外组织培养中的发现转化为阐明HCMV的 细胞相互作用导致HCMV诱导的出生缺陷。我们提出这项建议的目的是 确定HCMV在两个1号染色体位点上的特异性相互作用，以及由此导致的 巢蛋白1（NID 1）在1 q42和髓鞘蛋白零（MPZ）在1 q23，促进中枢神经系统功能障碍， PNS。我们发现这两种蛋白质的表达在感染的临床组织样品中下调。NID 1是 对发育中的大脑神经元迁移和神经网络兴奋性和可塑性至关重要。我们 发现表达的NID 1蛋白在感染后被主动降解。HCMV被膜蛋白的表达 pp 71在两个位点诱导断裂并下调NID 1。pp 71和绝缘子蛋白CTCF结合 在1 q42断裂位点和NID 1启动子。NID 1蛋白水平在感染后也会降低。 pp 71缺失病毒（AD 169 del 71），表明至少一种另外的病毒蛋白调节NID 1。HCMV 通过两种途径用两种病毒蛋白靶向NID 1，表明NID 1的消除提供了强选择性 病毒的优势。MPZ是PNS的主要神经鞘蛋白。MPZ的突变与 与晚发性SNHL有关MPZ的表达仅限于PNS的雪旺细胞，这似乎 不太可能为病毒提供任何选择性优势，这是MPZ调节脱靶的有力证据。 NID 1和MPZ的缺陷可能在发育过程中产生严重后果。我们假设HCMV 特异性下调NID 1，通过细胞外基质的重塑促进感染细胞的扩散。 以及1 q42和1 q23位点之间序列相似性 导致与1 q23位点的脱靶相互作用，下调MPZ，可能导致SNHL。我们 将确定1）HCMV如何下调NID 1，2）HCMV从这种下调中获得的益处，3） 如果MPZ以同样的方式调节，以及4）NID和MPZ下调的后果是什么？