Biology subjects

Lee, Y.

Publications and source records attributed to Lee, Y..

At least 253 records · Page 14Linked to original sources

bioRxiv2020

Random forest model for feature-based Alzheimer's disease conversion prediction from early mild cognitive impairment subjects

Alzheimers Disease (AD) conversion prediction from the mild cognitive impairment (MCI) stage has been a difficult challenge. This study focuses on providing an individualized MCI to AD conversion prediction using a balanced random forest model that leverages clinical data. In order to do this, 383 Early Mild Cognitive Impairment (EMCI) patients were gathered from the Alzheimers Disease Neuroimaging Initiative (ADNI). Of these patients, 49 would eventually convert to AD (EMCI_C), whereas the remaining 335 did not convert (EMCI_NC). All of these patients were split into training and testing data sets with 95 patients reserved for testing. Nine clinical features were selected, comprised of a mix of demographic, brain volume, and cognitive testing variables. Oversampling was then performed in order to balance the initially imbalanced classes. Our results showed that a random forest model was effective (93.6% accuracy) at predicting the conversion of EMCI patients to AD based on these clinical features. Additionally, we assessed the importance of each clinical feature at both the individual and model level for interpretation of the prediction itself. Our model could impact the clinical environment as a tool to predict the conversion to AD from a prodromal stage or to identify ideal candidates for clinical trials.

bioinformatics↗

bioRxiv2020

Spatiotemporal Dynamics of Intra-tumoral Dependence on NEK2-EZH2 Signaling in Glioblastoma Cancer Progression

The highly lethal brain cancer glioblastoma undergoes dynamic changes in molecular profile and cellular phenotype throughout tumor core establishment and in primary-to-recurrent tumor progression. These dynamic changes allow glioblastoma tumors to escape from multimodal therapies, resulting in patient lethality. Here, we identified the emergence of dependence on NEK2-mediated EZH2 signaling, specifically in therapy-resistant tumor core-located glioblastoma cells. In patient-derived glioblastoma core models, NEK2 was required for in vivo tumor initiation, propagation, and radio-resistance. Mechanistically, in glioblastoma core cells, NEK2 binds with EZH2 to prevent its proteasome-mediated degradation in a kinase-dependent manner. Clinically, NEK2 expression is elevated in recurrent tumors after therapeutic failure as opposed to their matched primary untreated cases, and its high expression is indicative of worse prognosis. For therapeutic development, we designed a novel NEK2 kinase inhibitor CMP3a, which effectively attenuated growth of murine glioblastoma models and exhibited a synergistic effect with radiation therapy. Collectively, the emerging NEK2-EZH2 signaling axis is critical in glioblastoma, particularly within the tumor core, and the small molecule inhibitor CMP3a for NEK2 is a potential novel therapeutic agent for glioblastoma.

cancer biology↗

bioRxiv2020

MolDiscovery: Learning Mass Spectrometry Fragmentation of Small Molecules

Identification of small molecules is a critical task in various areas of life science. Recent advances in mass spectrometry have enabled the collection of tandem mass spectra of small molecules from hundreds of thousands of environments. To identify which molecules are present in a sample, one can search mass spectra collected from the sample against millions of molecular structures in small molecule databases. This is a challenging task as currently it is not clear how small molecules are fragmented in mass spectrometry. The existing approaches use the domain knowledge from chemistry to predict fragmentation of molecules. However, these rule-based methods fail to explain many of the peaks in mass spectra of small molecules. Recently, spectral libraries with tens of thousands of labelled mass spectra of small molecules have emerged, paving the path for learning more accurate fragmentation models for mass spectral database search. We present molDiscovery, a mass spectral database search method that improves both efficiency and accuracy of small molecule identification by (i) utilizing an efficient algorithm to generate mass spectrometry fragmentations, and (ii) learning a probabilistic model to match small molecules with their mass spectra. We show our database search is an order of magnitude more efficient than the state-of-the-art methods, which enables searching against databases with millions of molecules. A search of over 8 million spectra from the Global Natural Product Social molecular networking infrastructure shows that our probabilistic model can correctly identify nearly six times more unique small molecules than previous methods. Moreover, by applying molDiscovery on microbial datasets with both mass spectral and genomics data we successfully discovered the novel biosynthetic gene clusters of three families of small molecules. AvailabilityThe command-line version of molDiscovery and its online web service through the GNPS infrastructure are available at https://github.com/mohimanilab/molDiscovery.

bioinformatics↗

bioRxiv2020

3D8, a nucleic acid-hydrolyzing scFv, confers antiviral activity against SARS-CoV-2 and multiple coronaviruses in vitro

BackgroundThe current pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the etiology of Coronavirus-induced disease 19 (COVID-19) and poses a critical public health threat worldwide. Effective therapeutics and vaccines against multiple coronaviruses remain unavailable. Single chain variable fragment (scFv), a recombinant antibody exhibits broad-spectrum antiviral activity against DNA and RNA viruses owing to its nucleic acid-hydrolyzing property. ObjectiveThis study is aimed to investigate an antiviral activity of 3D8 scFv against SARS-CoV-2 and other coronaviruses. Methods3D8, a recombinant scFv antibody was evaluated for antiviral activity against SARS-CoV-2, HCoV-OC43 and PEDV in Vero E6 cell cultures. Viral growth was quantified with quantitative RT-qPCR and plaque assay. Nucleic acid hydrolyzing activity of 3D8 was assessed through abzyme assays of in vitro viral transcripts and cell viability was determined by MTT assay. Results3D8 inhibited the replication of SARS-CoV-2, human coronavirus OC43 (HCoV-OC43), and porcine epidemic diarrhea virus (PEDV). Our results revealed the prophylactic and therapeutic effects of 3D8 scFv against SARS-CoV-2 in Vero E6 cells. Immunoblot and plaque assays showed the reduction of coronavirus nucleoproteins and infectious particles respectively in 3D8 scFv-treated cells. ConclusionsThis data demonstrates the broad-spectrum antiviral activity of 3D8 against SARS-CoV-2 and other coronaviruses. Thus, it could be considered a potential antiviral countermeasure against SARS-CoV-2 and zoonotic coronaviruses.

microbiology↗

bioRxiv2020

High resolution 3D imaging of liver reveals a central role for subcellular architectural organization in metabolism

Cells display complex intracellular organization through compartmentalization of metabolic processes into organelles, yet neither the resolution of these structures in the native tissue context nor its functional consequences are well understood. Here, we resolved the 3-dimensional organelle structural organization in large (>2.8x105m3) volumes of intact liver tissue (15 partial or full hepatocytes per condition) in high resolution (8nm isotropic pixel size) by utilizing enhanced Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) imaging, followed by deep-learning-based image segmentation and 3D reconstruction. We also performed a comparative analysis of subcellular structures in liver tissue of lean and obese animals and found marked alterations particularly in hepatic endoplasmic reticulum (ER), which undergoes massive structural re-organization in obesity characterized by marked disorganization of stacks of ER sheets and predominance of ER tubules. Finally, we demonstrated the functional importance of these structural changes upon experimental recovery of the subcellular organization and its marked impact on cellular and systemic metabolism. We conclude that hepatic subcellular organization and ERs architecture is highly dynamic, integrated with the metabolic state, and critical for adaptive homeostasis and tissue health.

cell biology↗

bioRxiv2020

Chirality-dependent anti-inflammatory effect of glutathione after spinal cord injury

Neuroinflammation forms a glial scar following a spinal cord injury (SCI). The injured axon cannot regenerate across the scar, suggesting permanent paraplegia. In this study, we report that d-chiral glutathione (D-GSH) suppresses the inflammatory response after SCI and leads to axon regeneration of the injured spinal cord to a greater extent than l-chiral glutathione (L-GSH). After SCI, axon regrowth in D-GSH-treated rats was significantly increased compared to that in L-GSH-treated rats (***p < 0.001). Secondary damage and motor function were significantly improved in D-GSH-treated rats compared to those outcomes in L-GSH-treated rats (**p < 0.01). Moreover, D-GSH significantly decreased pro-inflammatory cytokines and glial scar via inhibition of the mitogen-activated protein kinase (MAPK) signaling pathway compared to L-GSH (***p < 0.001). In primary cultured macrophages, we found that D-GSH undergoes more intracellular interaction with activated macrophages than L-GSH (***p < 0.001). These findings reveal a potential new regenerative function of chiral GSH in SCI and suggest that chiral GSH has therapeutic potential as a treatment of other diseases.

neuroscience↗

bioRxiv2020

Simultaneous, cell-intrinsic downregulation of PD-1 and TIGIT enhances the effector function of CD19-targeting CAR T cells and promotes an early-memory phenotype

CD19-targeting chimeric antigen receptor (CAR) T cells have become an important therapeutic option for patients with relapsed and refractory B cell malignancies. However, recent clinical data indicate that a significant portion of patients still do not benefit from the therapy owing to various resistance mechanisms, including high expression of multiple inhibitory immune checkpoint receptors on activated CAR T cells. Here, we report a lentiviral two-in-one CAR T approach in which two checkpoint receptors are downregulated simultaneously by a dual short-hairpin RNA (shRNA) cassette integrated into a CAR vector. Using this system, we evaluated CD19-targeting CAR T cells in the context of four different checkpoint combinations--PD-1/TIM-3, PD-1/LAG-3, PD-1/CTLA-4 and PD-1/TIGIT--and found that CAR T cells with PD-1/TIGIT downregulation uniquely exerted synergistic antitumor effects in mouse xenograft models compared with PD-1 single downregulation, and maintained cytolytic and proliferative capacity upon repeated antigen exposure. Importantly, functional and phenotypic analyses of CAR T cells as well as analyses of transcriptomic profiles suggested that downregulation of PD-1 enhances short-term effector function, whereas downregulation of TIGIT is primarily responsible for maintaining a less-differentiated/exhausted state, providing a potential mechanism for the observed synergy. The PD-1/TIGIT-downregulated CAR T cells generated from diffuse large B-cell lymphoma patient-derived T cells using a clinically applicable manufacturing process also showed robust antitumor activity and significantly improved persistence in vivo compared with conventional CD19-targeting CAR T cells. Overall, our results demonstrate that the cell-intrinsic PD-1/TIGIT dual downregulation strategy may prove effective in overcoming immune checkpoint-mediated resistance in CAR T therapy.

immunology↗

bioRxiv2020

Aberrant Ca2+ homeostasis in adipocytes links inflammation to metabolic dysregulation in obesity

Chronic metabolic inflammation is a key feature of obesity, insulin resistance and diabetes, although the initiation and propagation mechanisms of metaflammation are not fully established, particularly in the adipose tissue. Here we show that in adipocytes, altered regulation of the Ca2+ channel inositol triphosphate receptor (IP3Rs) is a key, adipocyte-intrinsic, event involved in the emergence and propagation of inflammatory signaling and the resulting insulin resistance. Inflammation, either induced by cytokine exposure in vitro or by obesity in vivo lead to increased expression and activity of IP3Rs in adipocytes in a JNK-dependent manner. This results in increased cytosolic Ca2+ and impaired insulin action. In mice, adipocyte-specific loss of IP3R1/2 protected against adipose tissue inflammation and insulin resistance despite significant diet-induced weight gain. Thus, this work reveals that IP3R over-activation and the resulting increase in cytosolic Ca2+ is a key link between obesity, inflammation and insulin resistance, and suggests that approaches to target adipocyte Ca2+ homeostasis may offer new therapeutic opportunities against metabolic diseases, especially since GWAS studies also implicate this locus in human obesity.

physiology↗

bioRxiv2020

Newly developed silicone airway stent (GINA stent): Mechanical characteristics and performance evaluation in pigs

OBJECTIVESCentral airway obstruction (CAO) is caused by various malignant and benign processes. Surgery is a preferred option for CAO, but if not possible, bronchoscopic treatment could be performed. Recently, bronchoscopic treatments have been improved. Particularly in airway stents, new attempts are being made to overcome the existing shortcomings of stents (migration, mucostasis, and granulation tissue formation). We recently developed a new silicone airway stent (GINA stent). The GINA stent has anti-migration design, dynamic structure enabling reduction of stent cross-sectional area, and radiopaqueness. We sought to evaluate mechanical characteristics and performance of our novel GINA stent in a pig tracheal stenosis model. METHODSAll tests were performed by comparing GINA stent [outer diameter (OD, mm) 14, length (L, mm) 55] with Dumon stent (OD14L50). Mechanical tests were done using digital force gage to determine the anti-migration force, expansion force, and flexibility. Short-term (3 weeks) performance was evaluated after stent implantations [GINA (n = 4) vs. Dumon (n = 3)] in a pig model of tracheal stenosis. RESULTSMechanical properties outcomes for GINA vs. Dumon: anti-migration force [18.4 vs. 12.8 Newton (N)]; expansion force (11.9 vs. 14.5 N); flexibility (3.1 vs. 4.5 N). Short-term (3 weeks) GINA vs. Dumon performances: mucus retention (0/4 vs. 0/3); granulation tissue formation (0/4 vs. 0/3); migration (1/4 vs. 2/3). CONCLUSIONSGINA stent demonstrated better mechanical properties than Dumon stent with a stent performance not inferior to Dumon stent.

physiology↗

bioRxiv2020

LH LepR neurons directly drive sustained food seeking behavior after AgRP neuronal deactivation via neuromodulation of NPY

The physiological need for energy evokes motivated feeding behaviours that help to ensure survival. However, the neural mechanisms underlying the generation of food motivation remain poorly understood. We investigated these mechanisms by subdividing feeding-related motivated behaviours into food-seeking, evaluating, and swallowing. Micro-endoscopic results indicated that neurons containing leptin receptors (LepRs) in the lateral hypothalamus (LH) are the major food-specific subpopulation of LHGABA neurons. Optogenetic manipulation of LHLepR neurons bidirectionally regulated both food-seeking and evaluating. Furthermore, micro-endoscope data revealed that distinct LHLepR neurons encode seeking and evaluating. Computational modelling analysis demonstrated that LHLepR neurons encode motivation, whereas neurons containing agouti-related peptide and neuropeptide Y (AgRP/NPY) encode the need for food. Additionally, slice studies revealed that NPY decreases inhibitory input to LHLepR neurons via LHGABA interneurons. This mechanism explains the permissive gate role of hunger (food need) in seeking/evaluating motivation. Together, the present study provides a comprehensive neural mechanism of how physiological needs drive distinct motivated behaviours.

neuroscience↗

bioRxiv2020

Tumor edge architecture in glioblastoma is constructed by inter-cellular signals from vascular endothelial cells

One of the hallmarks of glioblastoma (GBM) is extensive neovascularization. In addition to supplying blood and nutrients, vascular endothelial (VE) cells provide trophic support to GBM cells via paracrine signaling, the precise mechanisms of which are being unraveled. Here, using patient-derived GBM and VE cells as well as orthotopic GBM mouse models, we report that Endocan (ESM1), an endothelial-secreted proteoglycan, confers enhanced proliferative, migratory, and angiogenic properties to GBM cells and regulates their spatial identity. Mechanistically, Endocan exerts at least part of its functions via direct binding and activation of the PDGFRA receptor. Subsequent downstream signaling enhances chromatin accessibility of the Myc promoter and upregulates Myc expression inducing highly stable phenotypic changes in GBM cells. Furthermore, Endocan confers a radioprotection phenotype in GBM cells, both in vitro and in vivo. Inhibition of Endocan-PDGFRA signaling with ponatinib increases survival in the Esm1 wild-type but not in the Esm1 knock-out mouse GBM model. Our findings identify Endocan and its downstream signaling axis as a potential target to subdue the recurrence of GBM and further highlight the importance of vascular to tumor cell signaling for GBM biology. Significance statementIdentification of the Endocan/PDGFRA/Myc axis demonstrates an important role of VE cells in GBM malignancy. The contribution of Endocan to the development of GBM cell populations with different phenotypes reveal an additional pathway underlying the origin of GBM intratumoral heterogeneity. Targeting Endocan-mediated crosstalk may enhance the efficacy of GBM treatment.

cancer biology↗

bioRxiv2020

Single-dose intranasal administration of AdCOVID elicits systemic and mucosal immunity against SARS-CoV-2 in mice

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the urgent need for effective preventive vaccination to reduce burden and spread of severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) in humans. Intranasal vaccination is an attractive strategy to prevent COVID-19 as the nasal mucosa represents the first-line barrier to SARS-CoV-2 entry before viral spread to the lung. Although SARS-CoV-2 vaccine development is rapidly progressing, the current intramuscular vaccines are designed to elicit systemic immunity without conferring mucosal immunity. Here, we show that AdCOVID, an intranasal adenovirus type 5 (Ad5)-vectored vaccine encoding the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, elicits a strong and focused immune response against RBD through the induction of mucosal IgA, serum neutralizing antibodies and CD4+ and CD8+ T cells with a Th1-like cytokine expression profile. Therefore, AdCOVID, which promotes concomitant systemic and local mucosal immunity, represents a promising COVID-19 vaccine candidate.

immunology↗

bioRxiv2020

High-throughput phenotypic characterization of zebrafish CRISPR mutants of DNA repair genes

A systematic knowledge of the roles of DNA repair genes at the level of the organism has been limited due to the lack of appropriate experimental techniques. Here, we generated zebrafish loss-of-function mutants for 32 DNA repair and replication genes through multiplexed CRISPR/Cas9-mediated mutagenesis. High-throughput phenotypic characterization of our mutant collection revealed that three genes (atad5a, ddb1, pcna) are essential for proper embryonic development and hematopoiesis; seven genes (apex1, atrip, ino80, mre11a, shfm1, telo2, wrn) are required for growth and development during juvenile stage and six genes (blm, brca2, fanci, rad51, rad54l, rtel1) play critical roles in sex development. Furthermore, mutation in six genes (atad5a, brca2, polk, rad51, shfm1, xrcc1) displayed hypersensitivity to DNA damage agents. Further characterization of atad5a-/- mutants demonstrate that Atad5a is required for normal brain development and hematopoiesis. Our zebrafish mutant collection provides a unique resource for understanding of the roles of DNA repair genes at the organismal level.

developmental biology↗

bioRxiv2020

Terminal Modification, Sequence, and Length Determine Small RNA Stability in Animals

In animals, piRNAs, siRNAs, and miRNAs silence transposons, fight viral infections, and regulate gene expression. piRNA biogenesis concludes with 3' terminal trimming and 2'-O-methylation. Both trimming and methylation influence piRNA stability. Here, we report that trimming and methylation protect mouse piRNAs from different decay mechanisms. In the absence of 2'-O-methylation, mouse piRNAs with extensive complementarity to long RNAs become unstable. In flies, 2'-O-methylation similarly protects both piRNAs and siRNAs from complementarity-dependent destabilization. Animal miRNAs are unmethylated, and complementarity-dependent destabilization helps explain differences in miRNA decay rates in both mice and flies. In contrast, trimming protects mouse piRNAs from a separate degradation pathway unaffected by target complementarity but sensitive to the 3' terminal, untrimmed sequence. Because distinct sets of mouse piRNAs are protected by each of these mechanisms, loss of both trimming and 2'-O-methylation causes the piRNA pathway to collapse, demonstrating that these two small RNA modifications collaborate to stabilize piRNAs. HighlightsO_LI2'-O-methylation protects mouse and fly piRNAs from complementarity-dependent decay C_LIO_LI2'-O-methylation protects fly siRNAs with extensive complementarity to long RNAs C_LIO_LIComplementarity to long RNAs predicts the half-life of fly and mouse miRNAs C_LIO_LIMouse pre-piRNA decay reflects both pre-piRNA sequence and PIWI protein identity C_LI

molecular biology↗

bioRxiv2020

LoVIS-Seq reveals clonal dynamics of human-HSPC in humanized mice and vector integration bias

BackgroundCurrent understanding of hematopoiesis is largely derived from mouse models that are physiologically distant from humans. Humanized mice provide the most physiologically relevant small animal model to study human diseases, most notably preclinical gene-therapy studies. However, the clonal repopulation dynamics of human hematopoietic stem and progenitor cells (HSPC) in these animal models is only partially understood. Using a new clonal tracking methodology designed for small sample volumes, we aim to reveal the underlying clonal dynamics of human cell repopulation in a mouse environment. MethodsHumanized BLT (bone marrow-liver-thymus) mice were generated by transplanting lentiviral vector transduced human fetal liver HSPC (FL-HSPC) in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice implanted with a piece of human fetal thymus. We developed a methodology to track vector integration sites (VIS) in a mere 25{micro}l of mouse blood for longitudinal and quantitative clonal analysis of human HSPC repopulation in mouse environment. We explored transcriptional and epigenetic features of human HSPC for possible VIS bias. Results897 HSPC clones were longitudinally tracked in BLT mice--providing a first-ever demonstration of clonal dynamics and competitive expansion of therapeutic and control vector-modified human cell populations simultaneously repopulating in the same humanized mice. The polyclonal repopulation stabilized at 19 weeks post-transplant and the contribution of the largest clone doubled within 4 weeks. Moreover, 550 ([~]60%) clones persisted over 6 weeks and were highly shared between different organs. The normal clonal profiles confirmed the safety of our gene therapy vectors. Multi-omics analysis of human FL-HSPC revealed that 54% of vector integrations in repopulating clones occurred within {+/-}1kb of H3K36me3-enriched regions. ConclusionsHuman repopulation in mice is polyclonal and stabilizes more rapidly than that previously observed in humans. VIS preference for H3K36me3 has no apparent negative effects on HSPC repopulation. Our study provides a methodology to longitudinally track clonal repopulation in small animal models extensively used for stem cell and gene-therapy research and with lentiviral vectors designed for clinical applications. Results of this study provide a framework for understanding the clonal behavior of human HPSC repopulating in a mouse environment, critical for translating results from humanized mice models to the human settings.

molecular biology↗

bioRxiv2020

Rapid Establishment of Tracheal Stenosis in Pigs Using Endotracheal Tube Cuff Overpressure and Electrocautery

BackgroundCentral airway obstruction can be caused by cancer, tracheal intubation, or tuberculosis, among others. If surgery is contraindicated, bronchoscopic therapy may be performed. Bronchoscopic treatment for airway obstruction is continuously evolving. In particular, attempts to overcome the current shortcomings of airway stents (stent migration, mucostasis, and granulation tissue formation) are currently ongoing. To apply a new airway stent to humans, preclinical studies in an appropriate animal model is needed. Canine and porcine tracheas have been used as animal airway stenosis models. However, existing models take a long time to develop (3-8 weeks) and have a disadvantage that the mechanism of stenosis is different from that in humans. PurposeTo establish a new and fast tracheal stenosis model in pigs using a combination of cuff overpressure intubation and electrocautery. MethodsFourteen pigs were divided into three groups: tracheal cautery (TC) group (n = 3), cuff overpressure intubation (COI) group (n = 3), and COI-TC combination group (n = 8). Cuff overpressure (200/400/500 mmHg) was applied using a 9-mm internal diameter endotracheal tube. Tracheal cautery (40/60 watts) was performed using a rigid bronchoscopic electrocoagulator. After intervention, the pigs were observed for 3 weeks and bronchoscopy was performed every 7 days. When the cross-sectional area decreased by > 50%, it was judged that tracheal stenosis was established. ResultsThe time for tracheal stenosis was 14 days in the TC group and 7 days in the COI-TC combination group. In the COI group, no stenosis occurred. In the COI-TC group, electrocautery (40 watts) immediately after intubation for > 1 hour with a cuff pressure of 200 mmHg or more resulted in sufficient tracheal stenosis within 7 days. Moreover, the degree of tracheal stenosis increased in proportion to the cuff pressure and tracheal intubation time. ConclusionsThe combined use of cuff overpressure and electrocautery helped to establish tracheal stenosis in pigs rapidly. This animal model was technically simple and reproducible, and used a mechanism similar to that in human tracheal stenosis. It is expected to help develop new treatments for airway stenosis

physiology↗

bioRxiv2020

High-speed compressed-sensing fluorescence lifetime imaging microscopy of live cells

We present high-resolution, high-speed fluorescence lifetime imaging microscopy (FLIM) of live cells based on a compressed sensing scheme. By leveraging the compressibility of biological scenes in a specific domain, we simultaneously record the time-lapse fluorescence decay upon pulsed laser excitation within a large field of view. The resultant system, referred to as compressed FLIM, can acquire a widefield fluorescence lifetime image within a single camera exposure, eliminating the motion artifact and minimizing the photobleaching and phototoxicity. The imaging speed, limited only by the readout speed of the camera, is up to 100 Hz. We demonstrated the utility of compressed FLIM in imaging various transient dynamics at the microscopic scale.

bioengineering↗

bioRxiv2020

Stereotypic Neutralizing VH Clonotypes Against SARS-CoV-2 RBD in COVID-19 Patients and the Healthy Population

In six of seven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients, VH clonotypes, encoded by either immunoglobin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobin heavy joining (IGHJ)6, were identified in IgG1, IgA1, and IgA2 subtypes, with minimal mutations, and could be paired with diverse light chains, resulting in binding to the SARS-CoV-2 receptor-binding domain (RBD). Because most human antibodies against the RBD neutralized the virus by inhibiting host cell entry, we selected one of these clonotypes and demonstrated that it could potently inhibit viral replication. Interestingly, these VH clonotypes pre-existed in six of 10 healthy individuals, predominantly as IgM isotypes, which could explain the expeditious and stereotypic development of these clonotypes among SARS-CoV-2 patients.One Sentence Summary Stereotypic-naïve SARS-CoV-2 neutralizing antibody clonotypes, encoded by IGHV3-53/IGHV3-66 and IGHJ6, were identified in most patients and pre-exist in the majority of the healthy population, predominantly as an IgM isotype.Competing Interest StatementThe authors have declared no competing interest.View Full Text

immunology↗