Ontology highlight
ABSTRACT:
PROVIDER: PRJNA756264 | ENA |
REPOSITORIES: ENA
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Project description:Nanobodies are emerging as ideal instruments for drug design and several have recently been created to block SARS-Cov-2 entry in the host cell by targeting surface-exposed Spike protein. However, due to the high frequency of mutations that affect Spike, these nanobodies may not efficiently target Spike during viral entry. Here we have established a pipeline that instead targets highly conserved viral proteins that are made only after viral entry into the host cell when the SARS-Cov-2 RNA-based genome is translated. As proof of principle, we designed nanobodies against the SARS-CoV-2 non-structural protein Nsp9, required for replication of the viral genome. To find out if this strategy efficiently blocked viral replication, one of these anti-Nsp9 nanobodies, 2NSP23, previously characterized using immunoassays and NMR spectroscopy for epitope mapping, was encapsulated into lipid nanoparticles (LNP) as mRNA. We show that this nanobody, hereby referred to as LNP-mRNA-2NSP23, is internalized and translated in HEK293 cells. We next infected HEK293-ACE2 cells subjected to LNP-mRNA-2NSP23 with multiple SARS-CoV-2 variants. Analysis of total RNA isolated form infected cells treated or untreated with LNP-mRNA-2NSP23 using qPCR and RNA deep sequencing shows that the LNP-mRNA-2NSP23 nanobody protects HEK293-ACE2 cells and suppresses replication of several SARS-CoV-2 variants. These observations indicate that following translation, the nanobody 2NSP23 inhibits viral replication by targeting Nsp9 in living cells. We propose that LNP-mRNA-2NSP23 may be translated into an innovative technology to generate novel antiviral drugs highly efficient across coronaviruses.
2023-10-10 | GSE244714 | GEO
Project description:To identify cell adhesion molecules (CAMs) targeting bacterial membrane proteins within a synthetic bacteria-displayed nanobody library, we present a comprehensive whole-cell screening platform. This involves targeted amplicon sequencing to discover nanobodies targeting the natural adhesin, TraN. Furthermore, we employ deep mutational engineering to enhance the binding affinity of these nanobodies toward TraN.
2023-12-18 | GSE249103 | GEO
Project description:Severe fever with thrombocytopenia syndrome (SFTS) is an acute infectious disease caused by novel bunyavirus (SFTSV), with a mortality rate of 6.3% ~ 30%. To date, there is no specific treatment for SFTS. Previously, our studies demonstrate that SFTSV surface glycoprotein (Glycoprotein N, Gn) is a potential target for the development of SFTS vaccine or therapeutic antibodies, and anti-Gn neutralizing antibodies play a protective role in SFTS infection. Compared with traditional antibodies, nanobodies from camelids have various advantages including small molecular weight, high affinity, low immunogenicity and convenient production by gene engineering, etc. In this study, we combined next generation sequencing (NGS) with proteomics technology and bioinformatics analysis to high-throughput screen monoclonal anti-Gn nanobodies from camel immunized with Gn protein. We identified 19 anti-Gn monoclonal nanobody sequences, and selected 6 of them for recombinant protein expression and purification. Among these 6 anti-Gn nanobodies, nanobody 57493 was validated to be highly specific for Gn.
2024-01-26 | PXD032731 | Pride
Project description:SARS-CoV-2 has spread globally and caused the COVID-19 pandemic. Although passively delivered neutralizing antibodies against SARS-CoV-2 are in clinical trials, their mechanism of action in vivo is incompletely understood. Here, we define correlates of protection of neutralizing human monoclonal antibodies (mAbs) in SARS-CoV-2-infected mice. Whereas Fc effector functions are fully dispensable when mAbs are administered as prophylaxis, they are required for optimal protection as therapy. When given after infection, intact but not LALA-PG loss of Fc effector function variant mAbs reduce SARS-CoV-2 burden and lung disease in mice and hamsters. Fc engagement of neutralizing antibodies mitigates inflammation and improves respiratory mechanics, and transcriptional profiling suggests these phenotypes are associated with diminished innate immune signaling and enhanced tissue repair. Immune cell depletions establish that neutralizing mAbs require monocytes for therapeutic efficacy. Our study demonstrates that therapeutic neutralizing mAbs require Fc effector functions to reduce SARS-CoV-2 infection and modulate protective immune responses.
2021-03-01 | GSE161615 | GEO
Project description:The COVID-19 pandemic prompted an unprecedented effort to develop effective countermeasures against SARS-CoV-2. While efficacious vaccines and certain therapeutic monoclonal antibodies are available, here, we report the development, cryo-EM structures and functional analyses of distinct potent monoclonal antibodies (mAbs) that neutralize SARS-CoV-2 and its variant B.1.351. We established a platform for rapid identification of highly potent and specific SARS-CoV-2-neutralizing antibodies by high-throughput B cell receptor single cell sequencing of spike receptor binding domain immunized animals. We identified two highly potent and specific SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity. We also generated a bispecific antibody of these two lead clones. The lead monospecific and bispecific antibodies showed strong neutralization ability against prototypical SARS-CoV-2 and the highly contagious South African variant B.1.351 that post a further risk of reducing the efficacy of currently available therapeutic antibodies and vaccines. The lead mAbs showed potent in vivo efficacy against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We solved five cryo-EM structures at ~3 resolution of these neutralizing antibodies in complex with the ectodomain of the prefusion spike trimer, and revealed the molecular epitopes, binding patterns and conformations between the antibodies and spike RBD, which are distinct from existing antibodies. Our recently developed antibodies expand the repertoire of the toolbox of COVID-19 countermeasures against the SARS-CoV-2 pathogen and its emerging variants.
2022-01-11 | GSE174635 | GEO
Project description:Since the start of the coronavirus disease-2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused more than 2 million deaths worldwide. Many vaccines have been deployed to date; however, the continual evolution of the viral receptor binding domain (RBD) has recently challenged their efficacy. In particular, SARS-CoV-2 variants originating in South Africa (B.1.351) and the U.K. (B.1.1.7) have reduced plasma neutralization activity and crippled antibody cocktails that received emergency use authorization1-3. Whereas vaccines can be updated periodically to account for emerging variants, complementary strategies are urgently needed to overcome viral escape. One potential alternative are camelid VHHs (also known as nanobodies), which can access conserved epitopes often hidden to conventional antibodies4-6. We here isolate anti-RBD nanobodies from llamas and mice engineered to produce VHHs from alpacas, dromedaries and camels. Through neutralization assays and cryo-electron microscopy we identify two “nanomouse” VHHs that circumvent RBD antigenic drift by recognizing a domain conserved in coronaviruses, away from the ACE2 binding motif. Conversely, llama nanobodies recognize the RBD-ACE2 interphase and as monomers they are ineffective against E484K or N501Y substitutions. Notably, as homotrimers those same VHHs neutralize RBD variants with ultrahigh (pM) affinity, rivaling the most potent antibodies produced to date against SARS-CoV-2. We conclude that multivalent nanobodies can avert SARS-CoV-2 escape mutants and thus they represent promising tools to prevent COVID-19 mortality when vaccines are compromised.
2021-05-18 | GSE167310 | GEO
Project description:In the rapidly advancing field of synthetic biology, there exists a critical need for technology to discover targeting moieties for therapeutic biologics. We are developing developed INSPIRE-seq, an approach that utilizes a nanobody library and next-generation sequencing to identify nanobodies selected for complex environments. INSPIRE-seq enables the parallel enrichment of immune cell-binding nanobodies that penetrate the tumor microenvironment. Clone enrichment and specificity vary varies across immune cell subtypes in the tumor, lymph node, and spleen. INSPIRE-seq identified a dendritic cell binding clone that binds PHB2. Single-cell RNA sequencing revealed a connection with cDC1s, and immunofluorescence confirmed nanobody-PHB2 colocalization along cell membranes. Structural modeling and docking studies assisted binding predictions and will guide nanobody selection. In this work, we demonstrate that INSPIRE-seq offers an unbiased approach to examine complex microenvironments and assist in the development of nanobodies, which could serve as active drugs, modified to become drugs, or used as targeting moieties. microenvironment, which can be distinct from draining lymph nodes. To identify targets, we selected a clone enriched for dendritic cells that binds to PHB2. Using single cell RNA sequencing, we observe PHB2 signaling is associated with activation in cDC1’s. Immunofluorescence confirmed that the nanobody colocalizes with PHB2 in regions along the cell membrane. Structural modeling with AlphaFold2 and antibody docking using Rosetta assist binding site predictions, thus could be used to guide nanobody selection for future aims. This work shows that INSPIRE-seq can interrogate complex microenvironments and may assist in developing therapeutics.
2023-11-16 | GSE223428 | GEO
Project description:Respiratory tract vaccination has an advantage of needle-free delivery and induction of mucosal immune response in the portal of SARS-CoV-2 entry. We utilized human parainfluenza virus type 3 vector to generate constructs expressing the full spike (S) protein of SARS-CoV-2, its S1 subunit, or the receptor-binding domain, and tested them in hamsters as single-dose intranasal vaccines. The construct bearing full-length S induced high titers of neutralizing antibodies specific to S protein domains critical to the protein functions. Robust tissue-resident T cell responses in the lungs were also induced, which represent an additional barrier to infection and should be less sensitive than the antibody responses to mutations present in SARS-CoV-2 variants. Following SARS-CoV-2 challenge, animals were protected from the disease and detectable viral replication. Vaccination prevented induction of gene pathways associated with inflammation. These results indicate advantages of respiratory vaccination against COVID-19 and inform the design of mucosal SARS-CoV-2 vaccines.
2022-05-04 | GSE193288 | GEO
Project description:To further investigate the underlying mechanisms of severe acute respiratory syndrome (SARS) pathogenesis and evaluate the therapeutic efficacy of potential drugs and vaccines it is necessary to use an animal model that is highly representative of the human condition in terms of respiratory anatomy, physiology and clinical sequelae. The ferret, Mustela putorius furo, supports SARS-CoV replication and displays many of the symptoms and pathological features seen in SARS-CoV-infected humans. We have recently established a SARS-CoV infection-challenge ferret platform for use in evaluating potential therapeutics to treat SARS. The main objective of the current study was to extend our previous results and identify early host immune responses upon infection and determine immune correlates of protection upon challenge with SARS-CoV in ferrets. Keywords: time course This study is a simple time course (58 day) examination of host responses in 35 SARS-CoV (TOR2) infected ferrets with the addition of a challenge inoculation of SARS CoV (TOR2) at day 29 post infection. Three mock-infected ferrets are included as negative controls. Due to the unavailability of ferret microarrays, Affymetrix Canine 2.0 oligonucleotide arrays were chosen following sequence analysis of our ferret cDNA library (~5000 clones) and demonstration of high levels of homology (>80%) between dog and ferret.
2013-05-28 | E-GEOD-11704 | biostudies-arrayexpress