College of Life Sciences, Wuhan University, Wuhan, China.
China Center for Type Culture Collection, Wuhan University, Wuhan, China.
Front Cell Infect Microbiol. 2022 Jul 8;12:940906. doi: 10.3389/fcimb.2022.940906. eCollection 2022.
Foot-and-mouth disease virus (FMDV) could cause acute infection in host cells, or they could coexist with host cells to generate persistent infection. In persistent infection, the virus could survive for a long time in the host and could be transmitted between different host cells. In the case of FMDV-persistent infection cell line, there is a remarkable significant cellular heterogeneity in the FMDV-persistent infection cell line due to differences of viral load in the individual cells within the cell line. However, the mechanisms of FMDV-persistent infection are not well understood. It is now generally accepted that multiple factors contribute to the coevolution of viruses and cells during the course of persistent infection. The outcome would influence the development of persistent FMDV infection conjointly, reaching a state of equilibrium ultimately. Therefore, in order to elucidate the mechanism of cellular heterogeneity in FMDV-persistent infection cell line, single-cell sequencing was performed on BHK-Op, and pseudotime trajectory plot was draw through cell cluster. Based on the cell clusters, we predicted the development and progression of the FMDV-persistent infection. It could be well explained by the fact that, in BHK-Op cells, there are a fraction of infected cells and a fraction of virus-exposed but uninfected bystander cells. By further comparing the transcripts in cell clusters, we found that these genes were involved in changes in ribosome biogenesis, cell cycle, and intracellular signaling including the interferon signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway. Through comprehensive cross-tabulation analysis of differential expressed genes in various cluster of cells, we identified a high association of Fos, a downstream transcription factor of the MAPK/extracellular signal-regulated kinase (ERK) signaling pathway, with viral replication during the formation of FMDV-persistent infection. Through the further study of Fos, we found that downregulation of Fos facilitates viral clearance during FMDV-persistent infection. Upregulation of c-Raf, which is the upstream of the MAPK/ERK signaling pathway, could promote FMDV replication through downregulation of Fos. Our research is the first to provide insight into the mechanism of the formation FMDV-persistent infection through single-cell sequencing using persistent infection cell line. Pseudotime trajectory analysis was the first time to apply for FMDV-persistent infection cell line. Our work highlights the detailed overview of the evolution of FMDV-persistent infection. We also analyzed the differential expressed genes in the replication or elimination of FMDV within the host. We found that the MAPK/ERK signaling pathway and its downstream transcription factor Fos play an important role in FMDV-persistent infection.
口蹄疫病毒（FMDV）可在宿主细胞中引起急性感染，也可与宿主细胞共存产生持续性感染。在持续性感染中，病毒可以在宿主体内存活很长时间，并在不同的宿主细胞之间传播。在 FMDV 持续性感染细胞系中，由于细胞系中单个细胞内病毒载量的差异，FMDV 持续性感染细胞系中存在显著的细胞异质性。然而，FMDV 持续性感染的机制尚不清楚。现在普遍认为，在持续性感染过程中，多种因素共同促进了病毒和细胞的共同进化。结果将共同影响持续性 FMDV 感染的发展，最终达到平衡状态。因此，为了阐明 FMDV 持续性感染细胞系中细胞异质性的机制，我们对 BHK-Op 进行了单细胞测序，并通过细胞聚类绘制了伪时间轨迹图。基于细胞聚类，我们预测了 FMDV 持续性感染的发展和进展。这可以很好地解释这样一个事实，即在 BHK-Op 细胞中，有一部分感染细胞和一部分病毒暴露但未感染的旁观者细胞。通过进一步比较细胞聚类中的转录本，我们发现这些基因参与了核糖体生物发生、细胞周期和细胞内信号转导的变化，包括干扰素信号通路和丝裂原活化蛋白激酶（MAPK）信号通路。通过对不同细胞簇中差异表达基因的综合交叉制表分析，我们鉴定了 Fos，MAPK/细胞外信号调节激酶（ERK）信号通路的下游转录因子，与 FMDV 持续性感染形成过程中的病毒复制高度相关。通过对 Fos 的进一步研究，我们发现下调 Fos 可促进 FMDV 持续性感染期间的病毒清除。MAPK/ERK 信号通路的上游 c-Raf 的上调可通过下调 Fos 促进 FMDV 复制。我们的研究首次通过使用持续性感染细胞系的单细胞测序为 FMDV 持续性感染的形成提供了深入的见解。伪时间轨迹分析首次应用于 FMDV 持续性感染细胞系。我们的工作突出了 FMDV 持续性感染进化的详细概述。我们还分析了宿主内 FMDV 复制或消除的差异表达基因。我们发现 MAPK/ERK 信号通路及其下游转录因子 Fos 在 FMDV 持续性感染中发挥重要作用。
