Interactions between trichomonasviruses, their parasite host, and the human superhost

项目摘要 阴道毛滴虫病毒（TVV）是一种双链RNA病毒，存在于专性人类 寄生虫阴道毛滴虫（Tvag）。Tvag是人类疾病滴虫病的病原体， 世界上最常见的非病毒性传播感染。感染含TVV的寄生虫是 被认为通过增加促炎性细胞因子来增加这种疾病及其并发症的严重性。 人类超级宿主的反应在毛滴虫病毒属中有五个已知的物种（TVV 1，TVV 2， TVV 3、TVV 4和TVV 5），但迄今为止的大多数实验都是使用纯化的TVV 1病毒粒子或 含TVV 1的分离株，部分原因是TVV 1单独感染的Tvag分离株的可用性更高。TVVs 没有细胞外生命周期，而是随着寄生虫分裂而垂直传播。此外，本发明还 多个TVV种类可以共感染单个毛滴虫。因此，研究TVV对寄生虫的影响， 人类超级宿主一直是困难的，因为未感染的毛滴虫不能被感染以产生等基因TVV+ vs. TVV-菌株。使用核苷类似物2 '-C-甲基胞苷（2CMC），其最近已被报道， 明确滴虫的TVV-感染，我们已经产生了治愈和未治愈菌株产生的同基因对 来自同一个亲本分离株利用这些等基因对，我们提出了测试我们的假设，T。阴道毛 保持持续的病毒感染，这赋予原生动物适应性优势，并增加 对人类超级宿主的毒性到目前为止，我们已经进行了高通量RNA测序与一个 这样同基因配对以测量差异基因表达。在此过程中，我们确定了几个候选人， 可能参与将病毒复制限制在可耐受水平以维持长期病毒感染的基因。 坚持不懈这些差异表达的基因在很大程度上还没有被表征，但一些编码因子 与已知的RNA核酸外切酶和解旋酶具有同源性，我们假设这可能涉及限制 病毒复制在本项目的目标1中，我们建议在其他同基因对中进一步验证这些结果 为了确定Tvag用于维持稳定的滴虫病毒感染的因素。在目标2中，我们建议 确定TVV感染对Tvag增殖、形态和对人细胞的粘附的影响。我们 假设TVV将增加寄生虫的存活和附着，为 长期的TVV持续性。最后，在目标3中，我们建议将人类细胞对感染的反应与 TVV种属中的TVV+和TVV-毛滴虫。我们预计，TVV+ Tvag毒株，无论病毒 种，将引起比TVV-株更强的炎症反应。通过这项工作，我们希望能揭开 关于一种重要的人类病原体和一个有趣的研究病毒宿主的模型系统的有价值的信息 交互.

PROJECT SUMMARY Trichomonas vaginalis viruses (TVVs) are double stranded RNA viruses that persist in the obligate human parasite Trichomonas vaginalis (Tvag). Tvag is the causative agent of the human disease trichomoniasis, the most common nonviral sexually transmitted infection worldwide. Infection with TVV-containing parasites is thought to increase the severity of this disease and its complications by increasing the pro-inflammatory response by the human superhost. There are five known species in genus Trichomonasvirus (TVV1, TVV2, TVV3, TVV4, and TVV5), but most experiments to date have been performed using purified TVV1 virions or TVV1-containing isolates, due in part to the greater availability of Tvag isolates singly infected with TVV1. TVVs do not have an extracellular lifecycle and instead are transmitted vertically as the parasite divides. Further, multiple TVV species can coinfect a singular trichomonad. Thus, studying the effect of TVVs on the parasite and the human superhost has been difficult, as uninfected trichomonads cannot be infected to create isogenic TVV+ vs. TVV- strains. Using the nucleoside analog 2’-C-methylcytidine (2CMC), which has been recently reported to clear trichomonads of TVV-infection, we have generated isogenic pairs of cured and uncured strains generated from the same parent isolate. With these isogenic pairs, we propose to test our hypothesis that T. vaginalis maintains a persistent viral infection, which confers a fitness advantage to the protozoan and increases virulence to the human superhost. Thus far, we have performed high throughput RNA-sequencing with one such isogenic pair to measure differential gene expression. In doing so, we have identified several candidate genes that may be involved in limiting viral replication to tolerable levels in order to maintain long-term viral persistence. These differentially expressed genes have largely not been characterized, but some encode factors with homology to known RNA exonucleases and helicases, which we hypothesize might be involved in limiting viral replication. In Aim 1 of this project, we propose to further validate these results in additional isogenic pairs in order to define factors Tvag uses to maintain a stable trichomonasvirus infection. In Aim 2, we propose to determine impacts of TVV infection on Tvag proliferation, morphology, and adherence to human cells. We hypothesize that TVVs will increase parasite survival and attachment, providing an evolutionary explanation for long-term TVV persistence. Finally, in Aim 3, we propose to compare responses of human cells to infection with TVV+ and TVV- trichomonads across TVV species. We anticipate that TVV+ Tvag strains, regardless of virus species, will elicit stronger inflammatory responses than TVV- strains. Through this work, we hope to uncover valuable information about an important human pathogen and an intriguing model system to study virus–host interactions.