Project description:Bat adenoviruses are a group of recently identified adenoviruses (AdVs) which are highly prevalent in bats yet share low similarity to known AdVs from other species. In this study, deep RNA sequencing was used to analyze the transcriptome at five time points following the infection of a bat AdV in a kidney cell line derived from a myotis bat species. Evidence of AdV replication was observed with the proportion of viral RNAs ranging from 0.01% at 6 h to 1.3% at 18 h. Further analysis of viral temporal gene expression revealed three replication stages; the early stage genes encoding mainly for host interaction proteins, the intermediate stage genes for the DNA replication and assembly proteins, and the late stage genes for most structural proteins. Several bat AdV genes were expressed at stages that differed from their counterpart genes previously reported for human AdV. In addition, single-base resolution splice sites of several genes and promoter regions of all 30 viral genes were fully determined. Simultaneously, the temporal cellular gene expression profiles were identified. The most overrepresented functional categories of the differentially expressed genes were related to cellular immune response, transcription, translation, and DNA replication and repair. Taken together, the deep RNA sequencing provided a global, transcriptional profile of the novel BtAdV and the virus-host interactions, which will be useful for the understanding and investigation of AdV replication, pathogenesis and specific virus-bat interactions in future research. Deep RNA sequencing was used to analyze the transcriptome at five time points(0h,6h,8h, 12h 18h) following the infection of a bat AdV in a bat kidney cell.
Project description:Bats are tolerant to highly pathogenic viruses such as Marburg, Ebola, and Nipah, suggesting the presence of a unique immune tolerance toward viral infection. Here, we compared SARS-CoV-2 infection of human and bat (Rhinolophus ferrumequinum) pluripotent cells and fibroblasts. Since bat cells do not express an ACE2 receptor that allows virus infection, we transduced the human ACE2 receptor into the cells and found that transduced cells can be infected with SARS-CoV-2. Compared to human ESCs-hA, infected bat iPSCs-hA produced about a 100-fold lower level of infectious virus and displayed lower toxicity. In contrast, bat fibroblasts (BEF-hA) produced no infectious virus while being infectable and synthesizing viral RNA and proteins, suggesting abortive infection. Indeed, electron microscopy failed to detect virus-like particles in infected bat fibroblasts in contrast to bat iPSCs or human cells, consistent with the latter producing infectious viruses. This suggests that bat somatic but not pluripotent cells have an effective mechanism to control virus replication. Consistent with previous results by others, we find that bat cells have a constitutively activated innate immune system, which might limit SARS-CoV-2 infection compared to human cells.
Project description:Saliva is a convenient non-invasive source of liquid biopsy to monitor human health and diagnose diseases. In particular, extracellular vesicles (EVs) in saliva can potentially reveal clinically relevant information for systemic health. Recent studies have shown that RNA in saliva EVs could be exploited as biomarkers for disease diagnosis. However, there is no standardized protocol for profiling RNA in saliva EV nor clear guideline on selecting saliva fractions for biomarker analysis. To address these issues, we established a robust protocol for small RNA profiling from fractionated saliva. With this method, we performed comprehensive small RNA sequencing of four saliva fractions, including cell-free saliva (CFS), EV-depleted saliva (EV-D), exosome (EXO), and microvesicle (MV) from ten healthy volunteers. Methods: To address these issues, we established a robust protocol for small RNA profiling from fractionated saliva. With this method, we performed comprehensive small RNA sequencing of four saliva fractions, including cell-free saliva (CFS), EV-depleted saliva (EV-D), exosome (EXO), and microvesicle (MV) from ten healthy volunteers.
Project description:Bat adenoviruses are a group of recently identified adenoviruses (AdVs) which are highly prevalent in bats yet share low similarity to known AdVs from other species. In this study, deep RNA sequencing was used to analyze the transcriptome at five time points following the infection of a bat AdV in a kidney cell line derived from a myotis bat species. Evidence of AdV replication was observed with the proportion of viral RNAs ranging from 0.01% at 6 h to 1.3% at 18 h. Further analysis of viral temporal gene expression revealed three replication stages; the early stage genes encoding mainly for host interaction proteins, the intermediate stage genes for the DNA replication and assembly proteins, and the late stage genes for most structural proteins. Several bat AdV genes were expressed at stages that differed from their counterpart genes previously reported for human AdV. In addition, single-base resolution splice sites of several genes and promoter regions of all 30 viral genes were fully determined. Simultaneously, the temporal cellular gene expression profiles were identified. The most overrepresented functional categories of the differentially expressed genes were related to cellular immune response, transcription, translation, and DNA replication and repair. Taken together, the deep RNA sequencing provided a global, transcriptional profile of the novel BtAdV and the virus-host interactions, which will be useful for the understanding and investigation of AdV replication, pathogenesis and specific virus-bat interactions in future research.
Project description:Bats harbor highly virulent viruses that can infect other mammals, including humans, posing questions about their immune tolerance mechanisms. Bat cells employ multiple strategies to limit virus replication and virus-induced immunopathology, but the coexistence of bats and fatal viruses remains poorly understood. Here, we investigated the antiviral RNA interference (RNAi) pathway in bat cells and discovered that they have an enhanced antiviral RNAi response, producing canonical viral small interfering RNAs (vsiRNAs) upon Sindbis virus (SINV) infection that were missing in human cells. Disruption of Dicer function resulted in increased viral load for three different RNA viruses in bat cells, indicating an interferon-independent antiviral pathway. Furthermore, our findings reveal the simultaneous engagement of Dicer and pattern-recognition receptors (PRRs), such as retinoic acid-inducible gene I (RIG-I), with double-stranded RNA, suggesting that Dicer attenuates the interferon response initiation in bat cells. These insights advance our comprehension of the distinctive strategies bats employ to coexist with viruses.