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

项目总结 阴道毛滴虫病毒(TVV)是一种持续存在于专性人类体内的双链RNA病毒 阴道毛滴虫寄生虫(TVAG)TVAG是人类疾病滴虫病的病原体， 全球最常见的非病毒性性传播感染。感染含有TVV的寄生虫是 认为通过增加促炎作用来增加这种疾病及其并发症的严重性 人类超级宿主的回应。滴虫病毒属(TVV1、TVV2、TVV2、 TVV3、TVV4和TVV5)，但到目前为止大多数实验都是使用纯化的TVV1病毒粒子或 含有TVV1的分离株，部分原因是单独感染TVV1的TVAG分离株的可用性更高。电视电视 没有细胞外的生命周期，而是随着寄生虫的分裂而垂直传播。此外， 多种TVV可同时感染一种滴虫。因此，研究电视病毒对寄生虫的影响和 人类的超级宿主一直很难，因为未感染的滴虫不能被感染来产生同基因的TVV 与TVV-株的比较。使用核苷类似物2‘-C-甲基胞苷(2CMC)，它最近被报道 清除TVV感染的滴虫，我们已经产生了治愈株和未治愈株的等基因对 来自同一亲本分离株。利用这些同基因对，我们建议检验我们的假设，即阴道毛滴虫 维持持续的病毒感染，这为原生动物提供了健康优势，并增加了 对人类超级宿主的毒力。到目前为止，我们已经进行了高通量的RNA测序 这样的等位基因对来测量差异基因的表达。在这样做时，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，但有一些编码因子 与已知的RNA核酸外切酶和解旋酶同源，我们假设它们可能参与限制 病毒复制。在本项目的目标1中，我们建议在更多的同源基因对中进一步验证这些结果 为了确定TVAG用来维持滴虫病毒感染稳定的因素。在目标2中，我们建议 确定TVV感染对TVAG增殖、形态和对人类细胞黏附的影响。我们 假设TVV将增加寄生虫的存活率和依附性，为 TVV长期坚持。最后，在目标3中，我们建议将人类细胞对感染的反应与 TVV和TVV滴虫在TVV物种中的分布。我们预计TVV TVAG株，无论是什么病毒 与TVV毒株相比，TVV毒株会引起更强的炎症反应。通过这项工作，我们希望揭开 关于一种重要的人类病原体和研究病毒-宿主的有趣模型系统的有价值的信息 互动。

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.