Project description:Single-cell RNA sequencing (scRNA-seq) has aided greatly in the study of viruses to distinguish responses from infected versus bystander cells in complex systems. Many of these workstreams, however, are not directly compatible with the more stringent biosafety regulations of BSL-3 and BSL-4 laboratories. Here we show that TCL buffer (Qiagen), inactivates both Ebola virus (EBOV) and SARS-CoV-2, representative BSL-4 and BSL-3 viruses. We show that additional heat treatment was additionally sufficient to inactivate EBOV-containing samples, and had minimal effects on extracted RNA quality and downstream sequencing results.
Project description:Nipah virus (NiV) is a highly pathogenic, negative strand RNA paramyxovirus that has recently emerged from flying foxes to cause serious human disease. To study the poorly-understood role of nonstructural NiV proteins in NiV pathogenesis, we generated recombinant viruse lacking the expression of accesory NiV C protein (NiV∆C).
Project description:Nipah virus is a deadly paramyxovirus with 40-75% mortality and >750 cases since 1998. Currently there are no clinically approved vaccines or therapeutics to target infection. Nipah is an enveloped virus with two surface glycoproteins, the trimeric fusion (F) and tetrameric attachment glycoprotein (G). G is responsible for cellular attachment via binding to ephrin B2/B3. Glycosylation of Nipah G and its effects on receptor engagement has not previously been studied but is important as glycosylation impacts immunogenicity, receptor binding and structural conformations for other enveloped virus glycoproteins. Our phylogenetic and mass spectrometry analysis of sitespecific N-glycans of the Nipah G Malaysia strain revealed how N-glycosylation has evolved since the appearance of the virus in 1998. We discovered that the N481 N-glycosite is not conserved and although the glycan does not directly contribute to receptor binding, the threonine/serine in the glycosylation sequon is critical for maintaining long-range stability of individual G subunits that facilitates ephrin B2 binding affinity. Together, these data reveal plasticity of N-glycosylation sites across Nipah species and the presence of hydrogen bonding networks that contribute to G stability and host engagement, which is valuable information for understanding virus attachment/entry mechanisms as well as the rationale design of structure-based vaccines.
Project description:Single-cell RNA sequencing (scRNA-seq) technologies are instrumental to improving our understanding of virus-host interactions in cell culture infection studies and complex biological systems because they allow separating the transcriptional signatures of infected versus non-infected bystander cells. A drawback of using biosafety level (BSL) 4 pathogens is that protocols are typically developed without consideration of virus inactivation during the procedure. To ensure complete inactivation of virus-containing samples for downstream analyses, an adaptation of the workflow is needed. Focusing on a commercially available microfluidic partitioning scRNA-seq platform to prepare samples for scRNA-seq, we tested various chemical and physical components of the platform for their ability to inactivate Nipah virus (NiV), a BSL-4 pathogen that belongs to the group of nonsegmented negative-sense RNA viruses. The only step of the standard protocol that led to NiV inactivation was a 5 min incubation at 85 °C. To comply with the more stringent biosafety requirements for BSL-4-derived samples, we included an additional heat step after cDNA synthesis. This step alone was sufficient to inactivate NiV-containing samples, adding to the necessary inactivation redundancy. Importantly, the additional heat step did not affect sample quality or downstream scRNA-seq results.
Project description:Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analysed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity. We performed microarray gene expression profiling of NiV infected HUVEC cell (2 replicates) and of uninfected HUVEC cell (2 replicates).
Project description:Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analysed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity.
Project description:Numerous studies have described the efficacy of heat inactivation, gamma irradiation, or treatment with guanidium-based chaotropic salts (e.g. TRIzol®) for pathogen inactivation of biological samples to ensure biosafety and biosecurity. However, the effect of these methods on the greater serum proteome are less studied. Here we sought to comprehensively measure the effects of three routinely used pathogen inactivation methods on the serum proteome of Rhesus macaques by characterizing the serum proteome pre-and-post inactivation treatment. Using data independent aquisition-based shotgun LCMS/MS, we evaluated total peptide/protein detection and individual protein abundances (e.g. ALB, APOA1, and CRP) across inactivation methods and compared to their untreated controls. Specifically, we observed improved quantitative reproducibility in gamma-irradiated samples across biological, technical, and experimental replicates compared to chemical inactivation and different heat combinations. These findings represent the first direct, experimental comparisons of effective pathogen inactivation methods on the serologic profiles of non-human primates and provide useful criteria for evaluating methods for biological specimen inactivation prior to proteomic analysis.
Project description:Nipah virus (NiV) is a highly pathogenic, negative strand RNA paramyxovirus that has recently emerged from flying foxes to cause serious human disease. To study the poorly-understood role of nonstructural NiV proteins in NiV pathogenesis, we generated recombinant viruse lacking the expression of accesory NiV C protein (NiVM-bM-^HM-^FC). To analyse the molecular basis of NiVM-bM-^HM-^FC attenuation we have used the gene microarray approach to study early changes of gene expression in infected primary human endothelial cells, which is a major cellular target of human NiV infection. We performed microarray gene expression profiling of NiV infected HUVEC cell (2 replicates), of uninfected HUVEC cell (2 replicates) and of NiVM-bM-^HM-^FC infected HUVEC cell (2 replicates).
Project description:Nipah virus (NiV) is an emerging paramyxovirus which causes severe respiratory illness and deathly encephalitis in humans.Improving the ability of vaccines to induce strong, cellular, and humoral immune responses, remains the challenge to respond to Nipah and future Henipavirus infections rapidly and efficiently. A CD40.NiV vaccine has been engineered by fusing to the anti-CD40 monoclonal Ab the ectodomain of the Nipah G protein (Bangladesh strain) and immunogenic and conserved NiV F and N peptides. In mice, CD40.NiV promotes poly-antigenic T cell responses and significantly improves anti-NiV G IgG responses compared to the non-targeted NiV G immunogenic protein, in terms of avidity and neutralization potency. Immunogenicity was confirmed in the AGM (African Green Monkey) model, with induction of cross-neutralizing sera against circulating NiV strains and Hendra virus (HeV). Challenge experiment using NiV-B strain demonstrated the high protective efficacy of the vaccine with 100% survival in vaccinated group as compared to 100% lethality in controls. Surviving animals did not exhibit NiV viral replication in the blood, organs and swabs suggesting a sterilizing immunity conferred by the CD40.NiV vaccine. Taken together, results obtained with CD40.NiV vaccine are highly promising in terms of breadth and viral efficacy against NiV.