HiFiViral for SARS-CoV-2 is a simple-to-use, scalable, cost-effective solution for sequencing the entire SARS-CoV-2 genome. This fully kitted solution uses a novel approach that is robust to new variants and comprehensively detects all types of mutations.
High-throughput, single-copy sequencing reveals SARS-CoV-2 spike variants coincident with mounting humoral immunity during acute COVID-19
Tracking evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within infected individuals will help elucidate coronavirus disease 2019 (COVID-19) pathogenesis and inform use of antiviral interventions. In this study, we developed an approach for sequencing the region encoding the SARS-CoV-2 virion surface proteins from large numbers of individual virus RNA genomes per sample. We applied this approach to the WA-1 reference clinical isolate of SARS-CoV-2 passaged in vitro and to upper respiratory samples from 7 study participants with COVID-19. SARS-CoV-2 genomes from cell culture were diverse, including 18 haplotypes with non-synonymous mutations clustered in the spike NH2-terminal domain (NTD) and furin cleavage site regions. By contrast, cross-sectional analysis of samples from participants with COVID-19 showed fewer virus variants, without structural clustering of mutations. However, longitudinal analysis in one individual revealed 4 virus haplotypes bearing 3 independent mutations in a spike NTD epitope targeted by autologous antibodies. These mutations arose coincident with a 6.2-fold rise in serum binding to spike and a transient increase in virus burden. We conclude that SARS-CoV-2 exhibits a capacity for rapid genetic adaptation that becomes detectable in vivo with the onset of humoral immunity, with the potential to contribute to delayed virologic clearance in the acute setting.
Complete Mapping of Mutations to the SARS-CoV-2 Spike Receptor-Binding Domain that Escape Antibody Recognition
Antibodies targeting the SARS-CoV-2 spike receptor-binding domain (RBD) are being developed as therapeutics and are a major contributor to neutralizing antibody responses elicited by infection. Here, we describe a deep mutational scanning method to map how all amino-acid mutations in the RBD affect antibody binding and apply this method to 10 human monoclonal antibodies. The escape mutations cluster on several surfaces of the RBD that broadly correspond to structurally defined antibody epitopes. However, even antibodies targeting the same surface often have distinct escape mutations. The complete escape maps predict which mutations are selected during viral growth in the presence of single antibodies. They further enable the design of escape-resistant antibody cocktails—including cocktails of antibodies that compete for binding to the same RBD surface but have different escape mutations. Therefore, complete escape-mutation maps enable rational design of antibody therapeutics and assessment of the antigenic consequences of viral evolution.
New York City (NYC) has emerged as one of the epicenters of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. To identify the early transmission events underlying the rapid spread of the virus in the NYC metropolitan area, we sequenced the virus that causes coronavirus disease 2019 (COVID-19) in patients seeking care at the Mount Sinai Health System. Phylogenetic analysis of 84 distinct SARS-CoV-2 genomes indicates multiple, independent, but isolated introductions mainly from Europe and other parts of the United States. Moreover, we found evidence for community transmission of SARS-CoV-2 as suggested by clusters of related viruses found in patients living in different neighborhoods of the city.
Deep Mutational Scanning of SARS-CoV-2 Receptor Binding Domain Reveals Constraints on Folding and ACE2 Binding
The receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein mediates viral attachment to ACE2 receptor and is a major determinant of host range and a dominant target of neutralizing antibodies. Here, we experimentally measure how all amino acid mutations to the RBD affect expression of folded protein and its affinity for ACE2. Most mutations are deleterious for RBD expression and ACE2 binding, and we identify constrained regions on the RBD’s surface that may be desirable targets for vaccines and antibody-based therapeutics. But a substantial number of mutations are well tolerated or even enhance ACE2 binding, including at ACE2 interface residues that vary across SARS-related coronaviruses. However, we find no evidence that these ACE2-affinity-enhancing mutations have been selected in current SARS-CoV-2 pandemic isolates. We present an interactive visualization and open analysis pipeline to facilitate use of our dataset for vaccine design and functional annotation of mutations observed during viral surveillance.
HiFiViral SARS-CoV-2: A Kitted Solution for Genome Surveillance that is Robust Across Sample Input Quantities and New Variants
The COVID-19 pandemic continues to be a major global epidemiological challenge with the ongoing emergence of new strain lineages that are more contagious, more virulent, drug resistant and in some cases evade vaccine-induced immunity. In response, the HiFiViral SARS-CoV-2 kit (PacBio; Menlo Park, California) was developed as a scalable solution for the Sequel II and Sequel IIe systems. The HiFiViral SARS-CoV-2 is an easy to perform solution for surveillance of variants to support pandemic response by public health. With 80% of samples yielding complete genome coverage in a 96-plex run, the combination of long read lengths and a differentiated probe design provides highly accurate results and robust genome coverage across a range of Ct values.
Discover how HiFi reads enable every aspect of viral research, from understanding viral genomes to the host immune response.
PacBio Principle Scientist Elizabeth Tseng walks through the SMRT Link SARS-CoV-2 Workflow.
In this video Jonas Korlach, PacBio Chief Scientific Officer, shares how PacBio is partnering with LabCorp to use highly accurate long-read sequencing in support of global efforts for genome surveillance…
In this Labroots webinar, Meredith Ashby, Director of Microbial Genomics at PacBio, describes the utility of highly accurate long-read sequencing, known as HiFi sequencing, to understand the SARs-CoV-2 viral genome….
Studying microbial genomics and infectious disease? Learn how the PacBio Sequel II System can help advance your research, with first-hand perspectives from scientists who are investigating SARS-CoV-2 and COVID-19. In…
COVID-19 is caused by the infection of SARS-CoV-2, a member of the coronavirus family. Complete and accurate sequencing of the SARS-CoV-2 genome enables discovery and epidemiological tracing of mutations that…
Video Poster: Capture long-read isoform sequencing (Iso-Seq) for uncovering human isoform diversity in the brain and characterizing SARS-CoV2 viral RNAs
Most genes in eukaryotic organisms produce alternative isoforms, broadening the diversity of proteins and non-coding RNAs encoded by the genome. In contrast to other RNA sequencing platforms that rely on…