Biology subjects

Cui, C.

Publications and source records attributed to Cui, C..

At least 55 records · Page 3Linked to original sources

bioRxiv2021

A Versatile Linker for Probes Targeting Hydrolases via In Situ labeling

Hydrolases are important molecules that are involved in a wide range of biological functions and their activities are tightly regulated in healthy or diseased states. Detecting or imaging the activities of hydrolases, therefore, can reveal underlying molecular mechanisms in the context of cells to organisms, and their correlation with different physiological conditions can therefore be used in diagnosis. Due to the nature of hydrolases, substrate-based probes can be activated in their catalytic cycles, and cleavage of covalent bonds frees reporter moieties. For test-tube type bulk detection, spatial resolution is not a measure of importance, but for cell- or organism-based detection or imaging, spatial resolution is a key factor for probe sensitivity that influences signal-to-background ratio. One strategy to improve spatial resolution of the probes is to form a covalent linkage between the reporter moiety and intracellular proteins upon probe activation by the enzyme. In this work, we developed a generalizable linker chemistry that would allow in situ labeling of various imaging moieties via quinone methide species. To do so, we synthesized probes containing a monofluoromethyl or a difluoromethyl groups for {beta}-galactosidase activation, while using fluorescein as a fluorescent reporter. The labeling efficacy of these two probes was evaluated in vitro. The probe bearing a monofluormethyl group exhibited superior labeling efficiency in imaging {beta}-galactosidase activity in living cells. This study provides a versatile linker for applying quinone methide chemistry in the development of hydrolase-targeting probes involving in situ labeling.

biochemistry↗

bioRxiv2021

Generation of functional ciliates cholangiocytes from human pluripotent stem cells

The derivation of mature functional cholangiocytes from human pluripotent stem cells (hPSCs) would provide a model for studying the pathogenesis of cholangiopathies and for developing novel therapies to treat them. Current differentiation protocols are not efficient and give rise to cholangiocytes that are not fully mature, limiting their therapeutic applications. Here, we describe a new strategy to generate functional hPSC-derived cholangiocytes that display many characteristics of mature bile duct cells including high levels of CFTR and the presence of primary cilia capable of sensing flow. With this level of maturation, these cholangiocytes are amenable for testing the efficacy of new cystic fibrosis drugs and for studying the role of cilia in cholangiocyte development and function. Transplantation studies showed that the mature cholangiocytes generate ductal structures in the liver of immunocompromised mice providing the first indication that it may be possible to develop cell-based therapies to restore bile duct function in patients with biliary disease.

cell biology↗

bioRxiv2021

Modeling the bistable transition between cell phenotypes during limb precartilage condensation

The tetrapod limb skeleton is initiated in unpatterned limb bud mesenchyme by the formation of precartilage condensations. Here, based on time-lapse videographic analysis of a forming condensation in a high-density culture of chicken limb bud mesenchyme, we observe a phase transition to a more fluidized state for cells within spatial compacted foci (protocondensations that will progress to condensations), as reflected in their spatial confinement, cell-substratum interaction and speed of motion. Previous work showed that galectin-8 and galectin-1A, two proteins of the galactoside-binding galectin family, are the earliest determinants of this process in the chicken limb bud, and that their interactions in forming skeletogenic patterns of condensations can be interpreted mathematically through a reaction-diffusion-adhesion framework. Based on this framework, we use an ordinary differential equation-based approach to analyze the core switching modality of the galectin reaction network and characterize the states of the network independent of the diffusive and adhesive arms of the patterning mechanism. We identify two steady states where the concentrations of both galectins are respectively, negligible, and very high. An explicit Lyapunov function shows that there are no periodic solutions. For sigmoidal galectin production terms, the model exhibits a bistable switch that arises from a monostable state via saddle-node bifurcation. Our model therefore predicts that the galectin network exists in low and high expression states separated in space or time without any intermediate states. This provides a causal basis for the observed outside vs. inside transition observed in the in vitro video data. We performed a quantitative analysis of the distribution of galectin-1A in cultures of condensing chick limb mesenchymal cells and found that the interior of the protocondensations had concentrations of this protein (compared to the immediate exterior) over and above that expected from its higher cell density, consistent with the models predictions. The galectin-based patterning network is thus suggested, on theoretical grounds, to incorporate a core switch independent of any spatial or temporal dynamics, that drives the chondrogenic cell state transition in limb skeletogenesis.

developmental biology↗

bioRxiv2021

Intrinsic bias at non-canonical, β-arrestin-coupled seven transmembrane receptors

G protein-coupled receptors (GPCRs) are typically characterized by their seven transmembrane (7TM) architecture, and interaction with two universal signal-transducers namely, the heterotrimeric G-proteins and {beta}-arrestins ({beta}arrs). Synthetic ligands and receptor mutants have been designed to elicit transducer-coupling preferences and distinct downstream signaling outcomes for many GPCRs. This raises the question if some naturally-occurring 7TMRs may selectively engage one of these two signal-transducers, even in response to their endogenous agonists. Although there are scattered hints in the literature that some 7TMRs lack G-protein coupling but interact with {beta}arrs, an in-depth understanding of their transducer-coupling preference, GRK-engagement, downstream signaling and structural mechanism remains elusive. Here, we use an array of cellular, biochemical and structural approaches to comprehensively characterize two non-canonical 7TMRs namely, the human decoy D6 receptor (D6R) and the human complement C5a receptor (C5aR2), in parallel with their canonical GPCR counterparts, CCR2 and C5aR1, respectively. We discover that D6R and C5aR2 couple exclusively to {beta}arrs, exhibit distinct GRK-preference, and activate non-canonical downstream signaling partners. We also observe that {beta}arrs, in complex with these receptors, adopt distinct conformations compared to their canonical GPCR counterparts despite being activated by a common natural agonist. Our study therefore establishes D6R and C5aR2 as bona-fide arrestin-coupled receptors (ACRs), and provides important insights into their regulation by GRKs and downstream signaling with direct implications for biased agonism.

biochemistry↗

bioRxiv2021

A reservoir of stem-like CD8 T cells in the tumor-draining lymph node maintains the ongoing anti-tumor immune response

"Stem-like" TCF1+ CD8+ T cells (TSL) are necessary for long-term maintenance of T cell responses and the efficacy of immunotherapy but, as tumors contain signals that should drive T-cell terminal-differentiation, how these cells are maintained in tumors remains unclear. We found that a small number of TCF1+ tumor-specific CD8+ T cells were present in tumors throughout development. Yet, most intratumoral T cells differentiated as tumors progressed, corresponding with an immunologic shift in the tumor microenvironment (TME) from "hot" to "cold". By contrast, most tumor-specific CD8+ T cells in tumor-draining lymph nodes (dLNs) had functions and gene expression signatures similar to TSL from chronic LCMV infection and this population was stable over time, despite the changes in the TME. dLN T cells were the precursors of their more-differentiated intratumoral counterparts, and maintenance of TCF1 by intratumoral T cells required continuous migration from dLNs. Finally, TSL CD8 T cells were also present in LNs from lung adenocarcinoma patients, suggesting this population is also relevant in human disease. Thus, we propose that the dLN TSL reservoir has a critical function during tumor development in sustaining antitumor T cells during tumor development and protecting them from the terminal differentiation that occurs in the TME.

immunology↗

bioRxiv2020

Neoantigen-driven B cell and CD4+ T follicular helper cell collaboration promotes robust anti-tumor CD8+ T cell responses

CD4+ T follicular helper (TFH) cells provide help to B cells, which is critical for germinal center (GC) formation, but the importance of TFH-B cell interactions in cancer is unclear. We found TFH cells correlated with GC B cells and with prolonged survival of lung adenocarcinoma (LUAD) patients. To investigate further, we developed an LUAD model, in which tumor cells expressed B-cell- and T-cell-recognized neoantigens. Interactions between tumor-specific TFH and GC B cells were necessary for tumor control, as were effector CD8+ T cells. The latter were reduced in the absence of T cell-B cell interactions or the IL-21 receptor. IL-21 was produced primarily by TFH cells, development of which required B cells. Moreover, development of tumor-specific TFH cell-responses was also reliant upon tumors that expressed B-cell-recognized neoantigens. Thus, tumor-neoantigens themselves can control the fate decisions of tumor-specific CD4+ T cells by facilitating interactions with tumor-specific B cells. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/424168v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@f31b57org.highwire.dtl.DTLVardef@881959org.highwire.dtl.DTLVardef@1385ccdorg.highwire.dtl.DTLVardef@154ba3b_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

Tubular lysosomes harbor active ion gradients and poise macrophages for phagocytosis

Lysosomes adopt dynamic, tubular states that regulate antigen presentation, phagosome resolution and autophagy. To date, tubular lysosomes have been studied either by inducing autophagy or by activating immune cells, both of which lead to cell states where lysosomal gene expression differs from the resting state. Therefore, it has been challenging to pinpoint the specific biochemical properties lysosomes acquire upon tubulation that could drive their functionality. We describe a DNA-based assembly that tubulates lysosomes in macrophages without activating them. Lumenal proteolytic activity maps at single lysosome resolution revealed that tubular lysosomes were less degradative. Further, they showed striking proximal to distal lumenal pH and Ca2+ gradients. Such gradients had been predicted, but never previously observed. We now identify a role for tubular lysosomes whereby they poise resting macrophages for phagocytosis. The ability to tubulate lysosomes without having to starve or activate immune cells may help reveal new roles for tubular lysosomes.

cell biology↗

bioRxiv2020

Ribonucleotide reductase, a novel target for gonorrhea

Antibiotic resistant Neisseria gonorrhoeae (Ng) are an emerging public health threat due to increasing numbers of multidrug resistant (MDR) organisms. We identified two novel orally active inhibitors, PTC-847 and PTC-672, that exhibit a narrow spectrum of activity against Ng including MDR isolates. By selecting organisms resistant to the novel inhibitors and sequencing their genomes, we identified a new therapeutic target, the class Ia ribonucleotide reductase (RNR). Activity studies and negative stain electron microscopy of the Ng Ia RNR suggest that these inhibitors potentiate conversion of its active 2{beta}2 state to an inactive 4{beta}4 similar to states first identified with the Escherichia coli (Ec) Ia RNR. Resistance mutations in Ng map to the N-terminal, ATP cone domain of its subunit and disrupt the interaction with the {beta} subunit required to form the specific quaternary inhibited state. Oral administration of PTC-672 reduces Ng infection in a mouse model and may have therapeutic potential for treatment of Ng that is resistant to current drugs.

microbiology↗

bioRxiv2020

Dual-purpose isocyanides produced by Aspergillus fumigatus contribute to cellular copper sufficiency and exhibit antimicrobial activity

The maintenance of sufficient but non-toxic pools of metal micronutrients is accomplished through diverse homeostasis mechanisms in fungi. Siderophores play a well-established role for iron homeostasis; however, no copper-binding analogs have been found in fungi. Here we demonstrate that in Aspergillus fumigatus isocyanides derived from the xan biosynthetic gene cluster (BGC) bind copper, impact cellular copper content, and have significant metal-dependent antimicrobial properties. xan BGC-derived isocyanides are secreted and bind copper as visualized by a chrome azurol S (CAS) assay and inductively coupled plasma-mass spectrometry (ICP-MS) analysis of A. fumigatus intracellular copper pools demonstrated a role for xan cluster metabolites in the accumulation of copper. A. fumigatus coculture with A. nidulans, Candida albicans and a variety of pathogenic bacteria establish copper-dependent antimicrobial properties of xan BGC metabolites including inhibition of laccase activity. Similarly, inhibition of Pseudomonas aeruginosa by low concentrations of the xan isocyanide xanthocillin was copper-dependent. Other metals also reduced xanthocillins antimicrobial properties, but less efficiently than copper. As variations of the xan BGC exist in other filamentous fungi, we suggest that xanthocillin-like natural products represent a first example for fungal small molecules that serve to maintain copper sufficiency and mediate interactions with competing microbes. SignificanceMetal homeostasis is an integral part of metabolism for any organism. A vast array of small molecules are already known to mediate metal homeostasis in fungi and bacteria; however, unlike their bacterial counterparts, to-date there are no known fungal small molecules that function to maintain copper homeostasis. Discovery of copper binding small molecules produced by A. fumigatus gives insight into mechanisms other than the extensively studied copper transporters or metalloproteins for how fungi can regulate copper. This has important ecological implications as securing scarce nutrients is central for fitness and survival. Additionally, studying this mechanism in A. fumigatus provides a basis for investigation of copper regulation pathways in other fungi.

microbiology↗

bioRxiv2020

Population Pharmacokinetics of an Anti-PD-1 Antibody Camrelizumab in Patients with Multiple tumor types and model informed dosing strategy

Objective Camrelizumab, a programmed cell death 1 (PD-1) inhibitor, has been approved for the treatment of relapsed or refractory classical Hodgkin lymphoma. The aim of this study was to perform a population pharmacokinetics (PK) analysis of camrelizumab to quantify the impact of patient characteristics on PK and to investigate the appropriateness of flat dose in the dosing regimen.Methods A total of 3298 camrelizumab concentrations from 133 patients from four studies were analyzed using nonlinear mixed effects modeling. Covariate model building was conducted using stepwise forward addition and backward elimination. Monte Carlo simulation was conducted to compare exposures of 200 mg and 3 mg/kg every 2-week regimens.Results The PK of camrelizumab were adequately described by a two-compartment model with parallel linear and nonlinear clearances. Baseline albumin had significant effects on linear clearance, and weight had effects on inter-compartmental clearance. Moreover, 200 mg and 3 mg/kg regimens provide similar exposure distributions with no advantage to either dosing approach.Conclusion Population PK analysis provided an integrated evaluation of the impact of albumin and weight on the PK of camrelizumab. It also provided evidence that neither the flat-dose nor the weight-based dose regimen was advantageous over the other for most patients with tumors.Competing Interest StatementThis study was sponsored by Jiangsu Hengrui Medicine Co. Ltd. Guang-li Ma, Da Xu and Yu-ya Wang are employees of Jiangsu Hengrui Medicine Co. Ltd.AbbreviationsAICAkaike’s information criterion;AUCarea under the concentration-time curve;AUCsssteady-state area under the concentration-time curve;BSVBetween-subject variability;Ccamrelizumab concentration;C1concentration of central compartment;Caverage,sssteady-state average concentration;CLclearance;CLlinearclearance of linear elimination;Cmax,sssteady-state peak concentration;CLnonlinearclearance of nonlinear elimination;Cmin,sssteady-state trough concentration;CWRESconditional weighted residuals;DVobserved concentration;IPREDindividual predicted concentrations;k0infusion rate;k23elimination rate from central compartment to peripheral compartment;k32elimination rate from peripheral compartment to central compartment;klinearlinear elimination rate;knonlinearnonlinear elimination rate;KmMichaelis–Menten constant;mAbmonoclonal antibody;NONMEMnonlinear mixed effect modeling;PD-1programmed cell death 1 receptor;PKpharmacokinetics;PREDpopulation predicted concentration;Qinter-compartmental clearance;Q2Wevery 2 weeks;Vmmaximum elimination rate;VPCvisual predictive check;V1distribution volume of central compartment;V2distribution volume of peripheral compartment;WBCwhite blood cell.View Full Text

cancer biology↗

bioRxiv2020

Single-cell RNA-seq analysis reveals the pan-cancer transformation of adipose-derived stromal cells into COL11A1-expressing metastasis associated fibroblasts

During the last ten years, many research results have been referring to a particular type of cancer-associated fibroblasts associated with poor prognosis, invasiveness, metastasis and resistance to therapy in multiple cancer types, characterized by a gene expression signature with prominent presence of genes COL11A1, THBS2 and INHBA. Identifying the underlying biological mechanisms responsible for their creation may facilitate the discovery of targets for potential pan-cancer therapeutics. Using a novel computational approach for single-cell gene expression data analysis identifying the dominant cell populations in a sequence of samples from patients at various stages, we conclude that these fibroblasts are produced by a pan-cancer cellular transition originating from a particular type of adipose-derived stromal cells naturally present in the stromal vascular fraction of normal adipose tissue, having a characteristic gene expression signature. Focusing on a rich pancreatic cancer dataset, we provide a detailed description of the continuous modification of the gene expression profiles of cells as they transition from APOD-expressing adipose-derived stromal cells to COL11A1-expressing cancer-associated fibroblasts, identifying the key genes that participate in this transition. These results also provide an explanation to the well-known fact that the adipose microenvironment contributes to cancer progression. Author summaryComputational analysis of rich gene expression data at the single-cell level from cancer biopsies can lead to biological discoveries about the nature of the disease. Using a computational methodology that identifies the gene expression profile of the dominant cell population for a particular cell type in the microenvironment of tumors, we observed that there is a remarkably continuous modification of this profile among patients, corresponding to a cellular transition. Specifically, we found that the starting point of this transition has a unique characteristic signature corresponding to cells that are naturally residing in normal adipose tissue. We also found that the endpoint of the transition has another characteristic signature corresponding to a particular type of cancer-associated fibroblasts with prominent expression of gene COL11A1, which has been found strongly associated with invasiveness, metastasis and resistance to therapy in multiple cancer types. Our results provide an explanation to the well-known fact that the adipose tissue contributes to cancer progression, shedding light on the biological mechanism by which tumor cells interact with the adipose microenvironment. We provide a detailed description of the changing profile during the transition, identifying associated genes as potential targets for pan-cancer therapeutics inhibiting the underlying mechanism.

cancer biology↗

bioRxiv2020

RPRH: a web-based tool for the inference of potential roles of plant microRNAs in human body

Recently, increasing studies reported that plant microRNAs (miRNAs) from food could be absorbed through gastrointestinal tract to regulate the physiological processes of animals. These novel cross-kingdom regulatory roles of plant miRNAs open a new field in miRNA study and drug discovery, but the lack of corresponding bioinformatics tools limit the development of this field. In this study, we built a web-based tool, RPRH (Role of Plant microRNA in Human), to infer the potential roles of plant miRNAs in human and to profile the landscape of all documented plant miRNAs regulatory functions in human. Totally, RPRH included 10414 miRNAs from 82 plant species and 18062 annotation terms like diseases, pathway, gene ontology (GO), and drugs. RPRH represents a bioinformatics resource for further investigation of cross-kingdom regulations of plant miRNAs. Availabilityhttp://www.rnanut.net/rprh/

bioinformatics↗

bioRxiv2020

Cytotoxicity evaluation of chloroquine and hydroxychloroquine in multiple cell lines and tissues by dynamic imaging system and PBPK model

Chloroquine (CQ) and hydroxychloroquine (HCQ) have been used in treating COVID-19 patients recently. However, both drugs have some contradictions and rare but severe side effects, such as hypoglycemia, retina and cardiac toxicity. To further uncover the toxicity profile of CQ and HCQ in different tissues, we evaluated the cytotoxicity of them in 8 cell lines, and further adopted the physiologically-based pharmacokinetic models (PBPK) to predict the tissue risk respectively. Retina, myocardium, lung, liver, kidney, vascular endothelium and intestinal epithelium originated cells were included in the toxicity evaluation of CQ and HCQ respectively. The proliferation pattern was monitored in 0-72 hours by IncuCyte S3, which could perform long-term continuous image and video of cells upon CQ or HCQ treatment. CC50 and the ratio of tissue trough concentrations to CC50 (RTTCC) were brought into predicted toxicity profiles. The CC50 at 24 h, 48 h, 72 h of CQ and HCQ decreased in the time-dependent manner, which indicates the accumulative cytotoxic effect. HCQ was found to be less toxic in 7 cell types except cardiomyocytes H9C2 cells (CC50-48 h=29.55 M; CC50-72 h=15.26 M). In addition, RTTCC is significant higher in CQ treatment group compared to HCQ group, which indicates that relative safety of HCQ. Both CQ and HCQ have certain cytotoxicity in time dependent manner which indicates the necessity of short period administration clinically. HCQ has the less impact in 7 cell lines proliferation and less toxicity compared to CQ in heart, liver, kidney and lung.

pharmacology and toxicology↗

bioRxiv2020

Ratio of the interferon-γ signature to the immunosuppression signature predicts anti-PD-1 therapy response in melanoma

Immune checkpoint inhibitor (ICI) treatments produce clinical benefit in many patients. However, better pretreatment predictive biomarkers for ICI are still needed to help match individual patients to the treatment most likely to be of benefit. Existing gene expression profiling (GEP)-based biomarkers for ICI are primarily focused on measuring a T cell-inflamed tumour microenvironment that contributes positively to the response to ICI. Here, we identified an immunosuppression signature (IMS) through analysing RNA sequencing data from a combined discovery cohort (n = 120) consisting of three publicly available melanoma datasets. Using the ratio of an established IFN-{gamma} signature and IMS led to consistently better prediction of the ICI therapy outcome compared to a collection of nine published GEP signatures from the literature on a newly generated internal validation cohort (n = 55) and three published datasets of metastatic melanoma treated with anti-PD-1 (n = 48) and anti-CTLA-4 (n = 42) as well as in patients with gastric cancer treated with antiPD-1 (n = 45), demonstrating the potential utility of IMS as a predictive/prognostic biomarker that complements existing GEP signatures for immunotherapy.

immunology↗

bioRxiv2020

Ultrasensitive small molecule fluorogenic probe for human heparanase

Heparanase is a critical enzyme involved in the remodeling of the extracellular matrix (ECM), and its elevated expression has been linked with diseases such as cancer and inflammation. The detection of heparanase enzymatic activity holds tremendous value in the study of the cellular microenvironment, and search of molecular therapeutics targeting heparanase, however, assays developed for this enzyme so far have suffered prohibitive drawbacks. Here we present an ultrasensitive fluorogenic small-molecule probe for heparanase enzymatic activity. The probe exhibits a 756-fold fluorescence turn-on response in the presence of human heparanase, allowing one-step detection of heparanase activity in real-time with a picomolar detection limit. The high sensitivity and robustness of the probe are exemplified in a high-throughput screening assay for heparanase inhibitors.

biochemistry↗

bioRxiv2020

A Self-Immobilizing NIR Probe for Non-invasive Imaging of Senescence

Cellular senescence, a process that arrests the cell cycle, is a cellular stress response to various stimuli and is implicated in aging and age-related diseases. However, the understanding of senescence in living organisms is insufficient, largely due to the scarcity of sensitive tools for the detection of cellular senescence in vivo. Herein, we describe the development of a self-immobilizing near-infrared (NIR) probe that can be activated by senescence-associated {beta}- Galactosidase (SA-{beta}-Gal), a widely accepted senescence marker. The NIR fluorophore is turned on in the presence of SA-{beta}-Gal, and the self-immobilizing group, based on quinone methide chemistry, retains the fluorescence signal to the site of activation. This strategy significantly improves the sensitivity of the probe from the one we developed before. We demonstrate the non-invasive imaging of drug-induced senescence in mice models.

biochemistry↗

bioRxiv2020

Differential Expression and Interaction network construction of Noncoding RNA and mRNA in Heart Tissue associated with Tetralogy of Fallot

Tetralogy of Fallot (TOF) is still the most common and complicated cyanotic congenital heart defect of all congenital heart diseases with a 10% incidence. Surgery repair is often necessary in infancy. The etiology of TOF is complex and genetic and epigenetic mechanisms such as chromosomal abnormalities, gene mutations, nucleic acid modifications, non-coding RNA, and circular RNA(circRNA) play an important role in its occurrence. RNA not only plays an auxiliary role of genetic information carrier, but also plays a more important role in various regulatory functions. There are few studies on the action mechanism of non-coding RNA. Aim to gain more in-depth knowledge of TOF, we collected tissue samples of the right ventricular outflow tract of 5 TOF children with no other intracardiac and extracardiac malformations and 5 normal fetuses. We systematically analyzed the specific long non-coding RNA (lncRNA), microRNA(miRNA), circRNA and messenger RNA(mRNA) profiles of TOF. To our knowledge, there are no reports of genome-wide study of transcriptome in TOF and we first obtained meaningful differentially expressed lncRNAs, miRNAs, circle RNA and mRNAs.

genetics↗

bioRxiv2020

A common problem in the purification of calicivirus raised by molecular sieving: balance between purification and loss of viral particles

Caliciviridae is a group of RNA viruses could lead to gastrointestinal disease in humans and acute oral or upper respiratory tract disease in felines, no efficient vaccine so far. The preparation of immunogen is a challenge to obtain a safe and efficient vaccine candidate. Molecular sieving, due to the advantage of simple and fast purifying, is considered as a very powerful tool in calicivirus purification; however, also introduce mechanical damage to the viron. In this study, we took Feline Calicivirus (FCV), a common natural pathogen in cats as well as a classic model for caliciviruses studies, as a research object. Here, with the help of the cryo-electron microscope (cryo-EM), we collected particle images in both conditions of with and without molecular sieving post-processing, the impact of molecular sieving on FCV particles was evaluated by building a flexibility evaluation system after 3D classification. The results indicated that the molecular sieving will impact the stability of P domains through increasing flexibility. In addition, we successfully built up a scoring system to describe this flexibility of FCV P-domains, which can be extended to assess the purification effect to the entire calicivirus.

microbiology↗