Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “sarbecoviruses”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 recordsLinked to original sources

Programmable antibody-based chimeric entry receptors for sarbecoviruses.

Despite frequent spillover of sarbecoviruses, most SARS-related viruses discovered in animals fail to engage human ACE2 (hACE2), limiting mechanistic insight and risk assessment. Here we developed antibody-based chimeric entry receptors (ABCERs) that reprogram antibody-antigen recognition into a synthetic, cell-anchored receptor interface. By replacing the extracellular protease domain of hACE2 with single-chain variable fragments (scFvs) from broadly neutralizing antibodies, ABCERs mimic viral receptor engagement while preserving the intracellular architecture required for cathepsin L-dependent endocytic fusion. This modular design converts antibody specificity into a programmable entry module, supporting efficient infection and replication of diverse sarbecoviruses from both clinical and animal sources. Among the tested scFvs, E7 exhibited exceptional breadth, recognizing conserved epitopes shared across representative sarbecoviruses from all clades. Sera from Pfizer-BioNTech mRNA-vaccinated individuals potently blocked E7 binding to SARS-CoV-2 but showed limited cross-inhibition of E7 interactions with RBDs from hACE2-independent sarbecoviruses, revealing a substantial gap in current vaccine-induced humoral immunity. Together, our findings establish E7-based ABCERs as a programmable synthetic receptor platform that bridges antibody recognition and viral propagation, offering a universal tool for isolating, studying, and surveying sarbecoviruses beyond the hACE2-dependent paradigm.

Humans↗

A Multitrait Locus Regulates Sarbecovirus Pathogenesis.

Infectious diseases have shaped the human population genetic structure, and genetic variation influences the susceptibility to many viral diseases. However, a variety of challenges have made the implementation of traditional human Genome-wide Association Studies (GWAS) approaches to study these infectious outcomes challenging. In contrast, mouse models of infectious diseases provide an experimental control and precision, which facilitates analyses and mechanistic studies of the role of genetic variation on infection. Here we use a genetic mapping cross between two distinct Collaborative Cross mouse strains with respect to severe acute respiratory syndrome coronavirus (SARS-CoV) disease outcomes. We find several loci control differential disease outcome for a variety of traits in the context of SARS-CoV infection. Importantly, we identify a locus on mouse chromosome 9 that shows conserved synteny with a human GWAS locus for SARS-CoV-2 severe disease. We follow-up and confirm a role for this locus, and identify two candidate genes, CCR9 and CXCR6, that both play a key role in regulating the severity of SARS-CoV, SARS-CoV-2, and a distantly related bat sarbecovirus disease outcomes. As such we provide a template for using experimental mouse crosses to identify and characterize multitrait loci that regulate pathogenic infectious outcomes across species. IMPORTANCE Host genetic variation is an important determinant that predicts disease outcomes following infection. In the setting of highly pathogenic coronavirus infections genetic determinants underlying host susceptibility and mortality remain unclear. To elucidate the role of host genetic variation on sarbecovirus pathogenesis and disease outcomes, we utilized the Collaborative Cross (CC) mouse genetic reference population as a model to identify susceptibility alleles to SARS-CoV and SARS-CoV-2 infections. Our findings reveal that a multitrait loci found in chromosome 9 is an important regulator of sarbecovirus pathogenesis in mice. Within this locus, we identified and validated CCR9 and CXCR6 as important regulators of host disease outcomes. Specifically, both CCR9 and CXCR6 are protective against severe SARS-CoV, SARS-CoV-2, and SARS-related HKU3 virus disease in mice. This chromosome 9 multitrait locus may be important to help identify genes that regulate coronavirus disease outcomes in humans.

Animals↗

Characterization and evolutionary history of novel SARS-CoV-2-related viruses in bats from Cambodia.

Circulating bat coronaviruses present a significant pandemic threat, yet our understanding of their genetic diversity and evolutionary dynamics remains limited. Over 3 years, we sampled 1,462 bats in Cambodia's Steung Treng province, identifying extensive and diverse coronaviruses co-circulation. Using metatranscriptomic and amplicon sequencing, we generated 33 complete sarbecovirus genomes sequences, revealing novel lineages that cluster into four distinct groups, each associated with different Rhinolophus bat species. Our analysis highlights rapid migration and recombination of sarbecovirus lineages over short distances and timescales. Of note, the receptor-binding domains of two novel viral groups exhibit high similarity to SARS-CoV-2, and pseudovirus assays confirmed the ability of this spike protein to mediate entry into cells expressing human ACE2, suggesting a potential zoonotic risk. The observed genetic diversity underscores the urgent need for continuous surveillance to identify high-risk animal-to-human interfaces and inform pandemic preparedness.

Animals↗

Emergence of crucial evidence catalyzing the origin tracing of SARS-CoV-2.

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), its genetic and geographical origins remain unclear, resulting in suspicions about its natural origin. In one of our previous studies, we reported the presence of a furin cleavage site RRAR in the junction region between S1 and S2 subunits of the spike protein, which was discovered as the first crucial clue for the origin tracing of SARS-CoV-2. In the present study, we conducted an integrative analysis of new genome data from bat Sarbecovirus strains reported after the COVID-19 outbreak. The primary results included the identification of BANAL-20-52, Rp22DB159, and S18CXBatR24 as three close relatives of SARS-CoV-2 and the successful detection of seven out of nine key genomic features (designated as RC0-7 and ORF8) observed in wild types of SARS-CoV-2 in the three close relatives from Laos, Vietnam, and Yunnan province of China, respectively. The most significant contribution of the present study lies in the detection of RC1 in wild genotype in a bat Sarbecovirus population BANAL-20-52 belonging to. Encoding a segment of the NSP3 protein, RC1 was discovered as the second crucial clue for the origin tracing of SARS-CoV-2. Although RC0, encoding the junction furin cleavage site, remains undetected outside of the SARS-CoV-2 genome, Feuang of Laos is the sole place where eight of the nine wild-type features (RC1-7 and ORF8) have been detected.

SARS-CoV-2↗

Detecting SARS-CoV-2 cryptic lineages using publicly available whole genome wastewater sequencing data.

Beginning in early 2021, unique and highly divergent lineages of SARS-CoV-2 were sporadically found in wastewater sewersheds using a sequencing strategy focused on amplifying the most rapidly evolving region of SARS-CoV-2, the receptor binding domain (RBD). Because these RBD sequences did not match known circulating strains and their source was not known, we termed them "cryptic lineages". To date, more than 20 cryptic lineages have been identified using the RBD-focused sequencing strategy. Here, we identified and characterized additional cryptic lineages from SARS-CoV-2 wastewater sequences submitted to NCBI's Sequence Read Archives (SRA). Wastewater sequence datasets were screened for individual sequence reads that contained combinations of mutations frequently found in cryptic lineages but not contemporary circulating lineages. Using this method, we identified 18 cryptic lineages that appeared in multiple (2-81) samples from the same sewershed, including 12 that were not previously reported. Partial consensus sequences were generated for each cryptic lineage by extracting and mapping sequences containing cryptic-specific mutations. Surprisingly, seven of the mutations that appeared convergently in cryptic lineages were reversions to sequences that were highly conserved in SARS-CoV-2-related enteric bat Sarbecoviruses. The apparent reversion to bat Sarbecovirus sequences is consistent with the notion that SARS-CoV-2 adaptation to replicate efficiently in respiratory tissues preceded the COVID-19 pandemic.

SARS-CoV-2↗

Structural and functional characterization of a conserved cryptic epitope on SARS-CoV-2 spike S2 subunit.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has undergone extensive evolution since its emergence in 2019, underscoring the continuous need for vaccines and therapeutics effective against multiple variants of concern (VOCs). The S2 subunit of the viral spike (S) glycoprotein is highly conserved among sarbecoviruses, making it an attractive target for broadly protective countermeasures. To elucidate the S2 antigenic landscape, we employed yeast surface display to isolate S2-targeted antibodies from COVID-19 convalescent donors. Biophysical characterization revealed that these S2 apex-directed antibodies preferentially bind to open spike conformations and a stabilized S2 construct but not to the closed, trimeric prefusion spike. Cryo-electron microscopy structures defined a cryptic epitope encompassing the upper helix and fusion peptide proximal region on S2. This epitope is conserved among sarbecoviruses but remains largely occluded in the closed prefusion conformation of the spikes. As a result, the antibodies exhibited weak neutralization activity against SARS-CoV-2 pseudoviruses, failed to neutralize authentic viruses, and did not provide protection in a lethal mouse challenge model using a mouse-adapted SARS-CoV-2 strain. These findings highlight a non-neutralizing epitope on S2 capable of eliciting antibodies during SARS-CoV-2 infection in humans and provide valuable reagents for probing S2 conformational dynamics and optimizing S2-based vaccine antigens.

Spike Glycoprotein, Coronavirus↗

Coronavirus Cryptic Landscape and Draft Genome of a Novel CoV Clade Related to MERS From Bats Circulating in Northeastern Brazil.

We identified seven distinct coronaviruses (CoVs) in bats from Brazil, classified into 229E-related (Alpha-CoV), Nobecovirus, Sarbecovirus, and Merbecovirus (Beta-CoV), including one closely related to MERS-like CoV with 82.8% genome coverage. To accomplish this, we screened 423 oral and rectal swabs from 16 different bat species using molecular assays, RNA sequencing, and evolutionary analysis. Notably, gaps in the spike-encoding gene led us to design new primers and perform Sanger sequencing, which revealed high similarities to MERS-related (MERSr) CoV strains found in humans and camels. Additionally, we identified key residues in the receptor-binding domain (RBD) of the spike protein, suggesting potential interactions with DPP4, the receptor for MERSr-CoV. Our analyses also revealed evidence of recombination involving our laboratory-produced sequences. These findings highlight the extensive genetic diversity of CoVs, the presence of novel viral lineages, and the occurrence of recombination events among bat CoVs circulating in Brazil, underscoring the critical role bats play as reservoirs for emerging viruses and emphasizing the necessity of ongoing surveillance to monitor the public health risks associated with CoV spillover events.

Chiroptera↗

Genetic Conservation and Diversity of SARS-CoV-2 Envelope Gene Across Variants of Concern.

SARS-CoV-2 Envelope (E) protein is critical in viral assembly, release, and virulence. E gene was considered highly conserved and evolving slowly. Pan-sarbecoviruses-conserved regions in the E gene have been used as targets for various RT-PCR assays to detect SARS-CoV-2. It remains elusive whether SARS-CoV-2 variants of concern (VOCs) have accumulated significant E mutations that may affect protein stability and diagnostic RT-PCR assays. Herein we aimed to perform a comprehensive genetic analysis on the conservation and diversity of the E gene of SARS-CoV-2 and its VOCs in comparison with other human coronaviruses (HCoVs). In silico analysis of 20 326 HCoV E gene sequences retrieved from GenBank and GISAID suggests that SARS-CoV-2 E gene has multiple pan-HCoVs- and pan-SARS-CoV-2-conserved positions but accumulates significant mutations in VOC B.1.351 and Omicron strains. Mutations were often found in the 5' and 3' variable regions, whereas the central region is conserved. Nucleotide changes C109U and A114G may lead to potential failure of first-line SARS-CoV-2 diagnostic/screening assays. Nucleotide change C212U and its concomitant amino acid substitution Pro71Leu (i.e., C212U/Pro71Leu) is a hallmark mutation of B.1.351 variants, while C26U/Thr9Ile is characteristic of all Omicron variants. Later Omicron subvariants, such as XBB.1.5 and EG.5, additionally acquired the A31G/Thr11Ala mutation, as was confirmed by whole genome sequencing of SARS-CoV-2 in 118 pediatric cases. Wild-type E protein exhibits cytotoxicity to cells, but the mutations Thr9Ile, Thr11Ala, Thr9Ile + Thr11Ala, or Pro71Leu reduces its cytotoxicity. The Thr9Ile + Thr11Ala mutation stabilizes the E proteins of Omicron variants, while Pro71Leu alters the cellular distribution of the E protein, reducing its colocalization with the Golgi body. Altogether, this study not only sheds light on the conservation and diversity of the E gene in SARS-CoV-2 and its VOCs but also informs the improvement and development of SARS-CoV-2 or pan-HCoVs screening and diagnostic assays.

SARS-CoV-2↗