Project description:Set of microarray experiments used to identify an unknown coronavirus in a viral culture derived from a patient with SARS. March 2003. Keywords = SARS Keywords = coronavirus Keywords = viral discovery Keywords = viruses Keywords = respiratory infection
Project description:The ongoing pandemic of coronavirus disease 2019 (COVID-19), which results from the rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a significant global public health threat, with molecular mechanisms underlying its pathogenesis largely unknown. Small non-coding RNAs (sncRNAs) are known to play important roles in almost all biological processes. In the context of viral infections, sncRNAs have been shown to regulate the host responses, viral replication, and host-virus interaction. Compared with other subfamilies of sncRNAs, including microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), tRNA-derived RNA fragments (tRFs) are relatively new and emerge as a significant regulator of host-virus interactions. Using T4 PNK‐RNA‐seq, a modified next‐generation sequencing (NGS), we recently found that nasopharyngeal swabs (NPS) samples from SARS-CoV-2 positive and negative subjects show a significant difference in sncRNA profiles. There are about 166 SARS-CoV- 2-impacted sncRNAs. Among them, tRFs are the most significantly affected and almost all impacted tRFs are derived from the 5’-end of tRNAs (tRF5). Using a modified qRT-PCR, which was recently developed to specifically quantify tRF5s by isolating the tRF signals from its corresponding parent tRNA signals, we validated that tRF5s derived from tRNA GluCTC (tRF5-GluCTC), LysCTT (tRF5-LysCTT), ValCAC (tRF5-ValCAC), CysGCA (tRF5-CysGCA) and GlnCTG (tRF5-GlnCTG) are enhanced in NPS samples of SARS-CoV2 patients and SARS-CoV2-infected airway epithelial cells. In addition to host-derived ncRNAs, we also identified several sncRNAs derived from the virus (svRNAs), among which a svRNA derived from CoV2 genomic site 346 to 382 (sv-CoV2-346) has the highest expression. The induction of both tRFs and sv-CoV2-346 has not been reported previously, as the lack of the 3’-OH ends of these sncRNAs prevents them to be detected by routine NGS. In summary, our studies demonstrated the involvement of tRFs in COVID-19 and revealed new CoV2 svRNAs.
Project description:Bats are the most important natural reservoirs for a variety of emerging viruses that cause several illnesses in humans and other mammals. Increased viral shedding by bats is thought to be linked to an increased ability of many bat species to tolerate viral infection. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, is thought to have originated in bats, since viruses with high sequence similarity have been detected in bat feces. However, there is no robust in vitro model for assessing the SARS-CoV-2 infection in the bat GI tract. Here, we established gastrointestinal organoid cultures from Jamaican fruit bats (JFB, Artibeus jamaicensis), which replicated the characteristic morphology of the gastrointestinal epithelium and showed tissue specific gene expression patterns and cell differentiation. To analyze whether JFB intestinal epithelial cells are susceptible to SARS-CoV-2, we performed in vitro infection experiments. Increased SARS-CoV-2 RNA was found in both cell lysates and supernatants from the infected organoids after 48 h, and sgRNA also was detected, indicating that the JFB intestinal epithelium supports limited viral replication. However, no infectious virus was released into the culture media, and no cytopathic effects were observed. Gene expression studies revealed a significant induction of type I interferon and inflammatory cytokine genes in response to active SARS-CoV-2 virus but not to TLR agonist treatment. Untargeted analysis of the organoid proteome using data-independent acquisition mass spectrometry (DIA-MS) revealed a significant increase in proteins and pathways associated with inflammatory signaling, cell turnover and repair, and SARS-CoV-2 infection. Collectively, our data suggest that primary intestinal epithelial cells from JFBs are largely resistant to SARS-CoV-2 infection and cell damage, likely because they are able to mount a strong antiviral interferon and regenerative response upon infection.