Biology subjects

Zhu, Y.

Publications and source records attributed to Zhu, Y..

At least 559 records · Page 31Linked to original sources

bioRxiv2022

ROStrace detects oxidative stress in vivo and predicts progression of Alzheimer's disease pathology in APP/PS1 mice.

PurposeOxidative stress is implicated in the pathogenesis of the most common neurodegenerative diseases, such as Alzheimers disease (AD). However, tracking oxidative stress in the brain has proven difficult and impeded its use as a biomarker. Herein, we investigate the utility of a novel positron emission tomography (PET) tracer, [18F]ROStrace, as a biomarker of oxidative stress throughout the course of AD in the well-established APP/PS1 double mutant mouse model. MethodsPET imaging studies were conducted in wild-type (WT) and APP/PS1 mice at 3 different time points, representing early (5 mo.), middle (10 mo.), and advanced (16 mo.) life (n = 6-12, per sex). Semi-quantitation SUVRs of the plateau phase (40-60min post-injection; SUVR40-60) of ten brain subregions were designated by the Mirrione atlas and analyzed by Pmod. Statistical parametric mapping (SPM) was used to distinguish brain regions with elevated ROS in APP/PS1 relative to WT in both sexes. The PET studies were validated by ex vivo autoradiography and immunofluorescence with the parent compound, dihydroethidium. Results[18F]ROStrace retention was increased in the APP/PS1 brain compared to age-matched controls by 10 mo. of age (p < 0.0001), and preceded the accumulation of oxidative damage in APP/PS1 neurons at 16mo. (p < 0.005). [18F]ROStrace retention and oxidative damages were higher and occurred earlier in female APP/PS1 mice as measured by PET (p < 0.001), autoradiography and immunohistochemistry (p < 0.05). [18F]ROStrace differences emerged mid-life, temporally and spatially correlating with increased A{beta} burden (r2 = 0.36; p = 0.0003), which was also greatest in the female brain (p < 0.001). Conclusions[18F]ROStrace identifies increased oxidative stress and neuroinflammation in APP/PS1 female mice, concurrent with increased amyloid burden mid-life. Differences in oxidative stress during this crucial time may partially explain the sexual dimorphism in AD. [18F]ROStrace may provide a long-awaited tool to stratify at-risk patients who may benefit from antioxidant therapy prior to irreparable neurodegeneration.

neuroscience↗

bioRxiv2022

Identification and functional characterization of two heme uptake systems required for virulence of the fish pathogen Flavobacterium psychrophilum

Bacterial pathogens have a critical impact on aquaculture, a sector that accounts for half of the human fish consumption. Flavobacterium psychrophilum (phylum Bacteroidetes) is responsible for bacterial cold-water disease in salmonids worldwide. The molecular factors involved in host invasion, colonization and hemorrhagic septicaemia are mostly unknown. In this study, we identified two new TonB-dependent receptors, HfpR and BfpR, that are required for adaptation to iron conditions encountered during infection and for virulence in rainbow trout. Transcriptional analyses revealed that their expression is tightly controlled and upregulated under specific iron sources and concentrations. Characterization of deletion mutants showed that they act without redundancy: BfpR is required for optimal growth in the presence of high hemoglobin level, while HfpR confers the capacity to acquire nutrient iron from heme or hemoglobin under iron scarcity. The gene hfpY, co-transcribed with hfpR, encodes a protein related to the HmuY family. We demonstrated that HfpY binds heme and contributes significantly to host colonization and disease severity. Overall, these results are consistent with a model in which both BfpR and Hfp systems promote heme uptake and respond to distinct signals to adapt iron acquisition to the different stages of pathogenesis. Our findings give insight into the molecular basis of pathogenicity of a serious pathogen belonging to the understudied family Flavobacteriaceae and point to the newly identified heme receptors as promising targets for antibacterial development.

microbiology↗

bioRxiv2022

Genetic surveillance of SARS-CoV-2 Mpro reveals high sequence and structural conservation prior to the introduction of protease inhibitor Paxlovid

SARS-CoV-2 continues to represent a global health emergency as a highly transmissible, airborne virus. An important coronaviral drug target for treatment of COVID-19 is the conserved main protease (Mpro). Nirmatrelvir is a potent Mpro inhibitor and the antiviral component of Paxlovid. The significant viral sequencing effort during the ongoing COVID-19 pandemic represented a unique opportunity to assess potential nirmatrelvir escape mutations from emerging variants of SARS-CoV-2. To establish the baseline mutational landscape of Mpro prior to the introduction of Mpro inhibitors, Mpro sequences and its cleavage junction regions were retrieved from [~]4,892,000 high-quality SARS-CoV-2 genomes in GISAID. Any mutations identified from comparison to the reference sequence (Wuhan-hu-1) were cataloged and analyzed. Mutations at sites key to nirmatrelvir binding and protease functionality (e.g., dimerization sites) were still rare. Structural comparison of Mpro also showed conservation of key nirmatrelvir contact residues across the extended Coronaviridae family (alpha-, beta-, and gamma-coronaviruses). Additionally, we showed that over time the SARS-CoV-2 Mpro enzyme remained under purifying selection and was highly conserved relative to the spike protein. Now, with the EUA approval of Paxlovid and its expected widespread use across the globe, it is essential to continue large-scale genomic surveillance of SARS-CoV-2 Mpro evolution. This study establishes a robust analysis framework for monitoring emergent mutations in millions of virus isolates, with the goal of identifying potential resistance to present and future SARS-CoV-2 antivirals. ImportanceThe recent authorization of oral SARS-CoV-2 antivirals, such as Paxlovid, has ushered in a new era of the COVID-19 pandemic. Emergence of new variants, as well as selective pressure imposed by antiviral drugs themselves, raise concern for potential escape mutations in key drug binding motifs. To determine the potential emergence of antiviral resistance in globally circulating isolates and its implications for the clinical response to the COVID-19 pandemic, sequencing of SARS-CoV-2 viral isolates before, during, and after the introduction of new antiviral treatments is critical. The infrastructure built herein for active genetic surveillance of Mpro evolution and emergent mutations will play an important role in assessing potential antiviral resistance as the pandemic progresses and Mpro inhibitors are introduced. We anticipate our framework to be the starting point in a larger effort for global monitoring of the SARS-CoV-2 Mpro mutational landscape.

genomics↗

bioRxiv2022

Full-length transcriptome maps of reef-building coral illuminate the molecular basis of calcification, symbiosis, and circadian genes

BackgroundReef-building corals are critical species for sustaining coral reefs and are highly threatened by global climate change. However, relevant transcriptomic data largely rely on short-read sequencing, which severely limits the understanding of coral molecular mechanisms and leaves many important biological questions unresolved. ResultsWe sequenced the full-length transcriptomes of four common and frequently dominant reef-building corals, including two Robusta clade species, Pocillopora damicornis and Pocillopora verrucosa, and two Complexa clade species, Acropora muricata and Montipora foliosa, using the PacBio Sequel II platform. We obtained information on gene functions, structures and expression profiles. Among them, a comparative analysis of biomineralization-related genes provided insights into the molecular basis of coral skeletal density. The gene expression profiles of the symbiote Symbiodiniaceae were also isolated and annotated from the holobiont sequence data; these profiles showed more highly convergent traits related to gene structure and expression level than those of coral hosts. Interestingly, we observed that intracellular algal cells share some evolutionary convergence between intracellular symbiosis in corals and intracellular digestion in amphioxus. Finally, a phylogenetic analysis of key circadian clock genes among 27 evolutionarily representative species indicated that there are four key members in early metazoans, including cry genes; Clock or Npas2; cyc or Arntl; and tim, while per, as the fifth member, occurs in Bilateria. ConclusionsOur work overcomes the incompleteness of short-read sequencing and illuminates the molecular basis of calcification, symbiosis, and circadian genes, thus providing a foundation for further work on the manipulation of skeleton production or symbiosis to promote the survival of these important organisms.

evolutionary biology↗

bioRxiv2022

Genetic background and mistranslation frequency determine the impact of mistranslating tRNASerUGG

Transfer RNA variants increase the frequency of mistranslation, the mis-incorporation of an amino acid not specified by the "standard" genetic code, to frequencies approaching 10% in yeast and bacteria. Cells cope with these variants by having multiple copies of each tRNA isodecoder and through pathways that deal with proteotoxic stress. In this study, we define the genetic interactions of the gene encoding tRNASerUGG,G26A, which mistranslates serine at proline codons. Using a collection of yeast temperature sensitive alleles, we identify negative synthetic genetic interactions between the mistranslating tRNA and 109 alleles representing 91 genes, with nearly half of the genes having roles in RNA processing or protein folding and turnover. By regulating tRNA expression, we then compare the strength of the negative genetic interaction for a subset of identified alleles under differing amounts of mistranslation. The frequency of mistranslation correlated with impact on cell growth for all strains analyzed; however, there were notable differences in the extent of the synthetic interaction at different frequencies of mistranslation depending on the genetic background. For many of the strains the extent of the negative interaction with tRNASerUGG,G26A was proportional to the frequency of mistranslation or only observed at intermediate or high frequencies. For others the synthetic interaction was approximately equivalent at all frequencies of mistranslation. As humans contain similar mistranslating tRNAs these results are important when analyzing the impact of tRNA variants on disease, where both the individuals genetic background and the expression of the mistranslating tRNA variant need to be considered.

molecular biology↗

bioRxiv2022

Loss of transgene expression limits liver gene therapy in primates

Introductory ParagraphEfforts to improve liver gene therapy have focused on next-generation adeno-associated virus (AAV) vector capsids, transgene delivery, and immunomodulating drugs, such as corticosteroids, to avoid destructive T-cell responses. We conducted a detailed characterization of AAV transduction in nonhuman primate liver across multiple capsids and transgenes to better define interactions that may limit stable and efficient transgene expression. We show that the initial transduction of hepatocytes is high, but the transduction rapidly diminishes to a lower stable baseline of <1% of cells, even though ~10% of the cells retain vector DNA that is localized within the nucleus. Further characterization showed genomic vector integration at frequencies of 1/100 to 1/1,000 genomes, suggesting that one mechanism for stable expression may occur via genome integration. These studies suggest that strategies to enhance durable transgene expression by activating retained nuclear episomes or by increasing the frequency of vector integrations may improve liver directed AAV gene therapy.

molecular biology↗

bioRxiv2022

BNIP3 upregulation characterizes cancer cell subpopulation with increased fitness and proliferation

BNIP3 is a BH3 only protein with both pro-apoptotic and pro-survival roles depending on the cellular context. It remains unclear how BNIP3 RNA level dictates cell fate decisions of cancer cells. Here we undertook a quantitative analysis of BNIP3 expression and functions in single cell datasets of various epithelial malignancies. Our results demonstrated that BNIP3 upregulation characterizes cancer cell subpopulations with increased fitness and proliferation. We further validated the upregulation of BNIP3 in liver cancer organoids compared with 2D culture. Taken together, the combination of in silico perturbations using public single cell datasets and experimental cancer modeling using organoids ushered in a new approach to address cancer heterogeneity.

systems biology↗

bioRxiv2022

Tales of Two α-Carboxysomes: the Structure and Assembly of Cargo Rubisco

Carboxysomes are a family of bacterial microcompartments in cyanobacteria and chemoautotrophs. It encapsulates carbonic anhydrase and Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalysing carbon fixation inside a proteinaceous shell. How Rubisco packs into the carboxysomes is unknown. Using cryo-electron tomography and subtomogram averaging, we present 3D organization of Rubisco inside two types of native -carboxysomes from a marine -cyanobacterium Cyanobium sp. PCC 7001 and a chemoautotrophic bacterium Halothiobacillus neapolitanus. We determined the structures of Rubiscos within native Halothiobacillus and Cyanobium carboxysomes at 3.3 [A] and 3.8 [A] resolution respectively and further identified an associated CsoS2 segment. Interestingly, CsoS2 is only associated with a sub-population of Rubiscos that are close to the shell in Halothiobacillus, but with all Rubiscos throughout Cyanobium carboxysome. Moreover, Rubiscos in Cyanobium carboxysomes are organized in three concentric layers whereas Rubiscos in Halothiobacillus carboxysomes are arranged in spiral arrays. Calcium treatment induced a drastic re-organization of Rubiscos, converting these two distinct assemblies into ordered lattice arrays in both -carboxysomes. Our findings provide critical knowledge of the assembly principles of -carboxysomes, which may aid in rational design and repurpose of carboxysome structures for new functions.

microbiology↗

bioRxiv2022

Notch signaling in tumor vasculature programs cancer-associated fibroblasts to suppress anti-tumor immunity

Scarcity of tumor-infiltrating T cells poses significant challenges to cancer treatment, but mechanisms that regulate T cell recruitment into the tumor microenvironment are unclear. Here we ask if the endothelial lining of tumor vasculature suppresses T cell infiltration. Using mouse pancreatic ductal adenocarcinoma models, we found that Notch signaling in endothelial cells (ECs) inhibits the pro-inflammatory functions of cancer-associated fibroblasts (CAFs) and prevents CAFs from secreting CXCL10, a chemokine that recruits anti-tumor T cells via its receptor CXCR3. Abrogation of canonical Notch signaling in ECs reprogrammed the phenotype of CAFs from myofibroblasts into pro-inflammatory fibroblasts, unleashed interferon gamma (IFN{gamma}) responses in the tumor, and stimulated CXCL10/CXCR3-mediated recruitment of T cells to inhibit tumor growth. Collectively, these data uncover an important role of endothelial Notch signaling in shaping the tumor immune microenvironment, and suggest the potential of targeting EC-CAF crosstalk as an approach to enhance anti-tumor immunity in immunologically cold tumors. In briefHow blood vasculature shapes the tumor immune microenvironment is poorly defined. This study demonstrates that tumor endothelial cells reprogram cancer-associated fibroblasts to limit anti-tumor T cell recruitment, and suggests the potential of targeting endothelium-fibroblast crosstalk to overcome T cell scarcity in "cold" tumors and enhance anti-tumor immunity.

cancer biology↗

bioRxiv2022

Pancreas resident macrophage-induced fibrosis has divergent roles in pancreas inflammatory injury and PDAC

Tissue-resident macrophages (TRMs) are long-lived cells that maintain locally and can be phenotypically distinct from monocyte-derived macrophages (MDMs). However, whether TRMs and MDMs have functional distinction under differing pathologies is not understood. Here, we show a significant portion of macrophages that accumulated during pancreatitis and pancreatic cancer were expanded from TRMs. We further established that pancreas TRMs have a distinct extracellular matrix remodeling phenotype that was critical for maintaining tissue homeostasis during inflammation. Loss of TRMs led to exacerbation of severe pancreatitis and animal death, due to impaired acinar cell survival and recovery. In pancreatitis, TRMs elicited protective effects by triggering the accumulation and activation of fibroblasts, which was necessary for initiating fibrosis as a wound healing response. The same TRM-driven fibrosis, however, drove pancreas cancer pathogenesis and progression. Together, these findings indicate that TRMs play divergent roles in the pathogenesis of pancreatitis and cancer through regulation of stromagenesis.

immunology↗

bioRxiv2022

Targeting fatty acid beta-oxidation impairs monocyte differentiation and prolongs heart allograft survival

AO_SCPLOWBSTRACTC_SCPLOWMonocytes play an important role in the regulation of alloimmune responses after heart transplantation (HTx). Recent studies have highlighted the importance of immunometabolism in the differentiation and function of myeloid cells. While the importance of glucose metabolism in monocyte differentiation and function has been reported, a role for fatty acid {beta}-oxidation (FAO) has not been explored. Heterotopic HTx was performed using hearts from Balb/c donor mice implanted into C57Bl/6 recipient mice and treated with etomoxir (eto), an irreversible inhibitor of carnitine palmitoyltransferase 1 (Cpt1), a rate-limiting step of FAO, or vehicle control. FAO inhibition prolonged HTx survival, reduced early T cell infiltration/ activation and reduced dendritic cell (DC) and macrophage infiltration to heart allografts of eto-treated HTx recipients. ELISPOT demonstrated eto-treated HTx were less reactive to activated donor antigen presenting cells. FAO inhibition reduced monocyte-to-DC and monocyte-to-macrophage differentiation in vitro and in vivo. Further, FAO inhibition did not alter the survival of heart allografts when transplanted into Ccr2-deficient recipients, suggesting the effects of FAO inhibition on reduced immune cell infiltration and increased heart allograft survival were dependent on monocyte mobilization. Finally, we confirmed the importance of FAO on monocyte differentiation in vivo using conditional deletion of Cpt1a. Our findings demonstrate that targeting FAO attenuates alloimmunity after HTx, in part through impairing monocyte differentiation.

immunology↗

bioRxiv2022

Generating Functional Cells Through Enhanced Interspecies Chimerism with Human Pluripotent Stem Cells

Obtaining functional human cells through interspecies chimerism with human pluripotent stem cells (hPSCs) remains unsuccessful due to its extreamly low efficiency. Here, we show that hPSCs failed to differentiate and contribute teratoma in presence of mouse PSCs (mPSCs). While, MYCN, a pro-growth factor dramatically promotes hPSC contribution in teratoma co-formation by hPSCs/mPSCs. MYCN combined with BCL2 (M/B) greatly enhanced conventional hPSCs to integrate into preimplantation embryos of different species, such as mice, rabbits and pigs and substrantially contributed to mouse post-implantation chimera in embryonic and extra-embyonic tissues. Strikingly, M/B-hPSCs injected into preimplantation Flk-1+/- mouse embryos show further enhanced chimerism that allows obtaining live human CD34+ blood progenitor cells from chimeras through cell sorting. The chimera derived human CD34+ cells further gave rise to various subtype blood cells in typical colony forming unit(CFU) assay. Thus, we proof the concept to obtain functional human cells through enchanced interspecies chimerism with hPSCs.

cell biology↗

bioRxiv2022

Single-Cell Transcriptomic Analyses of Tumor Ecosystems and Spatial Architectures in Human Small Cell Lung Cancers

Small cell lung cancer (SCLC) is a highly heterogenous disease characterized by aggressive phenotypes and poor prognosis. In order to dissect the cellular components and their spatial distribution in SCLC ecosystems, here we performed single-cell RNA sequencing and spatial transcriptomics analyses of 12 resected human primary SCLCs. Our analysis revealed extensive heterogeneity of both tumor and non-tumor cells, and a predominant immunosuppressive microenvironment. Importantly, multiple hybrid tumor cell states were unmasked, including hybrid SCLC and lung adenocarcinoma cells as well as hybrid tumor and immune cells, indicating high phenotypic plasticity of tumor cells. Moreover, we revealed the cellular origin and evolution of these hybrid tumor cells, and critical roles of tumor-stromal cellular crosstalk in driving the development of hybrid cells. In conclusion, this study deepens our understanding of human SCLC ecosystems and provides rationales to target the hybrid tumor cells and immunosuppressive microenvironment for SCLC therapies.

cancer biology↗

bioRxiv2022

Joint embedding of biological networks for cross-species functional alignment

Model organisms are widely used to better understand the molecular causes of human disease. While sequence similarity greatly aids this transfer, sequence similarity does not imply functional similarity, and thus, several current approaches incorporate protein-protein interactions (PPIs) to help map findings between species. Existing transfer methods either formulate the alignment problem as a matching problem which pits network features against known orthology, or more recently, as a joint embedding problem. Here, we propose a novel state-of-the-art joint embedding solution: Embeddings to Network Alignment (ETNA). More specifically, ETNA generates individual network embeddings based on network topological structures and then uses a Natural Language Processing-inspired cross-training approach to align the two embeddings using sequence orthologs. The final embedding preserves both within and between species gene functional relationships, and we demonstrate that it captures both pairwise and group functional relevance. In addition, ETNAs embeddings can be used to transfer genetic interactions across species and identify phenotypic alignments, laying the groundwork for potential opportunities for drug repurposing and translational studies.

bioinformatics↗

bioRxiv2022

Structural basis for Nirmatrelvir in vitro efficacy against the Omicron variant of SARS-CoV-2

The COVID-19 pandemic continues to be a public health threat with emerging variants of SARS-CoV-2. Nirmatrelvir (PF-07321332) is a reversible, covalent inhibitor targeting the main protease (Mpro) of SARS-CoV-2 and the active protease inhibitor in PAXLOVID (nirmatrelvir tablets and ritonavir tablets). We evaluated the in vitro catalytic activity and in vitro potency of nirmatrelvir against the main protease (Mpro) of prevalent variants of concern (VOC) or variants of interest (VOI): Alpha (, B.1.1.7), Beta ({beta}, B.1.351), Delta ({delta}, B1.617.2), Gamma ({gamma}, P.1), Lambda ({lambda}, B.1.1.1.37/C37), Omicron (o, B.1.1.529) as well as the original Washington or wildtype strain. These VOC/VOI carry prevalent mutations at varying frequencies in the Mpro specifically for: , {beta},{gamma} (K90R), {lambda} (G15S) and o (P132H). In vitro biochemical enzymatic assay characterization of the enzyme kinetics of the mutant Mpros demonstrate that they are catalytically comparable to wildtype. Nirmatrelvir has similar potency against each mutant Mpro including P132H that is observed in the Omicron variant with a Ki of 0.635 nM as compared to a Ki of 0.933nM for wildtype. The molecular basis for these observations were provided by solution-phase structural dynamics and structural determination of nirmatrelvir bound to the o, {lambda} and {beta} Mpro at 1.63 - 2.09 [A] resolution. These in vitro data suggest that PAXLOVID has the potential to maintain plasma concentrations of nirmatrelvir many-fold times higher than the amount required to stop the SARS-CoV-2 VOC/VOI, including Omicron, from replicating in cells (1).

biochemistry↗

bioRxiv2022

Nirmatrelvir, an orally active Mpro inhibitor, is a potent inhibitor of SARS-CoV-2 Variants of Concern

New variants of SARS-CoV-2 with potential for enhanced transmission, replication, and immune evasion capabilities continue to emerge causing reduced vaccine efficacy and/or treatment failure. As of January 2021, the WHO has defined five variants of concern (VOC): B.1.1.7 (Alpha, ), B.1.351 (Beta, {beta}), P.1 (Gamma, {gamma}), B.1.617.2 (Delta, {delta}), and B.1.1.529 (Omicron, o). To provide a therapeutic option for the treatment of COVID-19 and variants, Nirmatrelvir, the antiviral component of PAXLOVID, an oral outpatient treatment recently authorized for conditional or emergency use treatment of COVID-19, was developed to inhibit SARS-CoV-2 replication. Nirmatrelvir (PF-07321332) is a specific inhibitor of coronavirus main protease (Mpro, also referred to as 3CLpro), with potent antiviral activity against several human coronaviruses, including SARS-CoV-2, SARS-CoV, and MERS (Owen et al, Science 2021. doi: 10.1126/science.abl4784). Here, we evaluated PF-07321332 against the five SARS-CoV-2 VOC (, {beta}, {gamma}, {delta},, o) and two Variants of Interest or VOI, C.37 ({lambda}) and B.1.621 (), using qRT-PCR in VeroE6 cells lacking the P-glycoprotein (Pgp) multidrug transporter gene (VeroE6 P-gp knockout cells). Nirmatrelvir potently inhibited USA-WA1/2020 strain, and , {beta}, {gamma}, {lambda}, {delta}, , and o variants in VeroE6 P-gp knockout cells with mean EC50 values 38.0 nM, 41.0 nM, 127.2 nM, 24.9 nM, 21.2 nM, 15.9 nM, 25.7 nM and 16.2 nM, respectively. Sequence analysis of the Mpro encoded by the variants showed ~100% identity of active site amino acid sequences, reflecting the essential role of Mpro during viral replication leading to ability of Nirmatrelvir to exhibit potent activity across all the variants.

microbiology↗

bioRxiv2022

ASGR1 is a candidate receptor for SARS-CoV-2 that promotes infection of liver cells

Backgroud & AimsCurrently, the COVID-19 pandemic, caused by SARS-CoV-2 infection, represents a serious public health problem worldwide. Although it has been shown that ACE2 serves as the main receptor for SARS-CoV-2 entry into host cells, studies have shown that ACE2 is expressed at extremely low levels in various tissues, especially in some organs where virus particles have been found, such as the heart and liver. Therefore, these organs potentially express additional SARS-CoV-2 receptors that have not yet been discovered. Methods & ResultsHere, by a genome-wide CRISPR-Cas9 activation library screening, we found that ASGR1 promoted SARS-CoV-2 infection of 293T cells. In Huh-7 and HepG2 cell lines, simultaneous knock out of ACE2 and ASGR1 prevented SARS-CoV-2 pseudovirus infection. In the immortalized THLE-2 hepatocyte cell line and primary liver parenchymal cells, both of which hardly express ACE2, SARS-CoV-2 could successfully establish an infection. After treatment with ASGR1 antibody, the infection rate significantly reduced. This suggests that SARS-CoV-2 infects liver cells mainly through an ASGR1-dependent mechanism. Finally, we also found that the soluble ASGR1 could not only prevent the SARS-CoV-2 pseudovirus, which binds to the ASGR1 receptors, from infecting host liver cells, but also had a protective effect on those expressing ACE2, indicating that administration of soluble ASGR1 protein may represent a new treatment approach. ConclusionsColletively, these findings indicate that ASGR1 is a candidate receptor for SARS-CoV-2 that promotes infection of liver cells. Lay SummaryWe show that ASGR1 is a candidate receptor for SARS-CoV-2 to infect liver cells.

microbiology↗

bioRxiv2022

Allogeneic gene-edited HIV-specific CAR-T cells secreting PD-1 blocking scFv enhance anti-HIV activity in vitro

HIV-specific chimeric antigen receptor (CAR) T cells have been developed to target latently infected CD4+ T cells that express virus either spontaneously or after intentional latency reversal. However, the T-cell exhaustion and the patient-specific autologous paradigm of CAR-T hurdled the clinical application. Here, we created HIV-specific CAR-T cells using human peripheral blood mononuclear cells and a 3BNC117-E27 CAR (3BE CAR) construct that enables the expression of PD-1 blocking scFv E27 and the single-chain variable fragment of the HIV-1-specific broadly neutralizing antibody 3BNC117 to target native HIV envelope glycoprotein (Env). In comparison with T cells expressing 3BNC117-CAR alone, 3BE CAR-T cells showed greater anti-HIV potency with stronger proliferation capability, higher killing efficiency (up to ~75%) and enhanced cytokine secretion in the presence of HIV envelope glycoprotein-expressing cells. Furthermore, our approach achieved high levels (over 97%) of the TCR-deficient 3BE CAR-T cells with the functional inactivation of endogenous TCR to avoid graft-versus-host disease without compromising their antiviral activity relative to standard anti-HIV CAR-T cells. These data suggest that we have provided a feasible approach to large-scale generation of "off-the-shelf" anti-HIV CAR-T cells in combination with antibody therapy of PD-1 blockade, which can be a powerful therapeutic candidate for the functional cure of HIV.

bioengineering↗