COMPARATIVE MOLECULAR BIOLOGY AND GENOME STRUCTURE OF HRV-C

项目总结（见说明）：本项目将比较和对比人鼻病毒C（HRV-C）与更知名的HRV-A和HRV-B种属病毒的分子生物学。HRV通常与普通感冒有关，但最近的研究清楚地表明，这些病毒，特别是HRV-C，与下呼吸道感染和喘息性疾病密切相关。这是第一个病毒蛋白质的工作，在感染的前2-3小时，在第一个感染的细胞中，关闭基本的哨兵宿主反应系统。进化已经非常精细的HRV蛋白酶（2Apro和3Cpro）与物种和菌株特异性偏好的关键细胞底物。我们假设，由任何个体HRV引起的免疫警报的大小在其起源处具有2Apro在第一轮感染中发挥作用的功效。拟议的实验将首次记录2Apro基因型的多样性内和之间的3个HRV物种，以及在生化和细胞水平的多样性的后果。它将利用我们独特的、新发现的培养HRV-Cs的能力来识别这些病毒的细胞受体，并揭示它们的比较分子秘密。鉴于许多HRV-C的天然分离株在2Apro区域中被定位为重组体（具有HRV-A），理解这种蛋白质对个体病毒-宿主界面的贡献是什么、如何以及为什么是至关重要的。具体而言，本项目提出了三个目标：1）鉴定HRV-C细胞受体和被该病毒感染的天然细胞类型; 2）通过研究可比较的重组2Apro对病毒诱导的宿主核质运输关闭的关键细胞蛋白的活性来确定病毒特异性2Apro序列变异的生物化学后果;和3）使用源自HRV-A、HRV-B和HRV-C cDNA的全长重组嵌合病毒，测试种和株特异性2Apro基因和/或5 ′非翻译区（UTR）是否影响病毒复制和免疫应答。这些实验将利用项目I中收集的上皮细胞和临床HRV分离株，并将与项目3进行广泛的智力和实验互动，以确定2Apro对单细胞中HRV生长和细胞间传播的作用。

PROJECT SUMMARY (See instructions): This project will compare and contrast the molecular biology of human rhinovirus C (HRV-C) to viruses in the better known HRV-A and HRV-B species. HRV are canonically linked to the common cold, but more recent studies have clearly established that these viruses, and especially HRV-C, are closely linked to lower respiratory infections and wheezing illnesses. It's the job of the first viral proteins produced in the first 2-3 hrs of infection, in the first infected cells, to shutoff essential sentinel host response systems. Evolution has superbly refined HRV proteases (2Apro and 3Cpro) with species and strain-specific preferences for key cellular substrates. We hypothesize that the magnitude of the immunological alarms set off by any individual HRV have at their origin, the efficacy with which 2Apro does its jobs in the first round(s) of infection. The proposed experiments will document for the first time, the 2Apro genotype diversity within and among the 3 HRV species, and the consequences of that diversity at the biochemical and cellular levels. It will exploit our unique, new-found ability to grow HRV-Cs to identify the cellular receptor for these viruses and expose their comparative molecular secrets. Given that many natural isolates of the HRV-C are mapped recombinants (with the HRV-A) in the 2Apro region, it is paramount to understand what, how and why this protein contributes to individual virus-host interfaces. Specifically, this project proposes three aims: 1) to identify the HRV-C cellular receptor and the natural cell type(s) infected by this virus; 2) to determine the biochemical consequences of virus-specific 2Apro sequence variation by studying the activities of comparable recombinant 2Apro towards cell proteins crucial for virus-induced shutoff of host nucleocytoplasmic trafficking; and 3) using full-length recombinant, chimeric viruses derived from HRV-A, HRV-B, and HRV-C cDNAs, test whether species- and strain-specific 2Apro genes and/or 5' untranslated regions (UTR) influence viral replication and immune responses. These experiments will utilize epithelial cells and clinical HRV isolates collected in Project I, and there will be extensive intellectual and experimental interactions with Project 3 to determine the role of 2Apro on HRV growth in single cells and cell-to-cell transmission.