Anti-Oxidized Self-Assembly of Multilayered F-Mene/MXene/TPU Composite with Improved Environmental Stability and Pressure Sensing Performances

MXenes, as emerging 2D sensing materials for next-generation electronics, have attracted tremendous attention owing to their extraordinary electrical conductivity, mechanical strength, and flexibility. However, challenges remain due to the weak stability in the oxygen environment and nonnegligible aggregation of layered MXenes, which severely affect the durability and sensing performances of the corresponding MXene-based pressure sensors, respectively. Here, in this work, we propose an easy-to-fabricate self-assembly strategy to prepare multilayered MXene composite films, where the first layer MXene is hydrogen-bond self-assembled on the electrospun thermoplastic urethane (TPU) fibers surface and the anti-oxidized functionalized-MXene (f-MXene) is subsequently adhered on the MXene layer by spontaneous electrostatic attraction. Remarkably, the f-MXene surface is functionalized with silanization reagents to form a hydrophobic protective layer, thus preventing the oxidation of the MXene-based pressure sensor during service. Simultaneously, the electrostatic self-assembled MXene and f-MXene successfully avoid the invalid stacking of MXene, leading to an improved pressure sensitivity. Moreover, the adopted electrospinning method can facilitate cyclic self-assembly and the formation of a hierarchical micro-nano porous structure of the multilayered f-MXene/MXene/TPU (M-fM2T) composite. The gradient pores can generate changes in the conductive pathways within a wide loading range, broadening the pressure detection range of the as-proposed multilayered f-MXene/MXene/TPU piezoresistive sensor (M-fM2TPS). Experimentally, these novel features endow our M-fM2TPS with an outstanding maximum sensitivity of 40.31 kPa-1 and an extensive sensing range of up to 120 kPa. Additionally, our M-fM2TPS exhibits excellent anti-oxidized properties for environmental stability and mechanical reliability for long-term use, which shows only ~0.8% fractional resistance changes after being placed in a natural environment for over 30 days and provides a reproducible loading-unloading pressure measurement for more than 1000 cycles. As a proof of concept, the M-fM2TPS is deployed to monitor human movements and radial artery pulse. Our anti-oxidized self-assembly strategy of multilayered MXene is expected to guide the future investigation of MXene-based advanced sensors with commercial values.

Prophylactic efficacy of an intranasal spray with 2 synergetic antibodies neutralizing Omicron

BACKGROUNDAs Omicron is prompted to replicate in the upper airway, neutralizing antibodies (NAbs) delivered through inhalation might inhibit early-stage infection in the respiratory tract. Thus, elucidating the prophylactic efficacy of NAbs via nasal spray addresses an important clinical need.METHODSThe applicable potential of a nasal spray cocktail containing 2 NAbs was characterized by testing its neutralizing potency, synergetic neutralizing mechanism, emergency protective and therapeutic efficacy in a hamster model, and pharmacokinetics/pharmacodynamic (PK/PD) in human nasal cavity.RESULTSThe 2 NAbs displayed broad neutralizing efficacy against Omicron, and they could structurally compensate each other in blocking the Spike-ACE2 interaction. When administrated through the intranasal mucosal route, this cocktail demonstrated profound efficacy in the emergency prevention in hamsters challenged with authentic Omicron BA.1. The investigator-initiated trial in healthy volunteers confirmed the safety and the PK/PD of the NAb cocktail delivered via nasal spray. Nasal samples from the participants receiving 4 administrations over a course of 16 hours demonstrated potent neutralization against Omicron BA.5 in an ex vivo pseudovirus neutralization assay.CONCLUSIONThese results demonstrate that the NAb cocktail nasal spray provides a good basis for clinical prophylactic efficacy against Omicron infections.TRIAL REGISTRATIONwww.chictr.org.cn, ChiCTR2200066525.FUNDINGThe National Science and Technology Major Project (2017ZX10202203), the National Key Research and Development Program of China (2018YFA0507100), Guangzhou National Laboratory (SRPG22-015), Lingang Laboratory (LG202101-01-07), Science and Technology Commission of Shanghai Municipality (YDZX20213100001556), and the Emergency Project from the Science & Technology Commission of Chongqing (cstc2021jscx-fyzxX0001).

Study on the Biotransformation and Activities of Astragalosides from Astragali Radix In Vitro and In Vivo

Astragalosides (AGs), as one of the main active ingredients in Astragali Radix (AR), have a series of biological activities. Previous studies have only qualitatively identified the metabolites of AGs in AR, resulting in a lack of quantification. In the present study, the original material was selected from 12 origins based on the levels of 4 AGs by high-performance liquid chromatography (HPLC). The prototype components and metabolites of total AGs (TAGs) in feces, urine, and plasma samples of rats were thoroughly screened and characterized by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). The fermentation reaction and metabolites were verified by human fecal TAG fermentation in vitro. The metabolites of AG I, II, and IV transformed by human feces at different times were identified using UHPLC-HRMS, and the partial metabolites were quantified by HPLC. Furthermore, the anti-inflammatory and antioxidant activities of the metabolites were evaluated based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells in vitro. In total, 13 AGs and 170 metabolites were identified in TAGs as well as in the plasma, urine, and feces of Sprague-Dawley (SD) rats by UHPLC-HRMS, including 28, 36, and 170 metabolites in the plasma, urine, and feces, respectively. The metabolites included the products of deglycosylation, demethylation, hydroxylation, glucuronidation, sulfation, and cysteine-binding reactions. Moreover, the TAG fermentation results in vitro showed great similarity. The human fecal incubation experiments for AG I, II, and IV demonstrated that the metabolic reaction of TAGs mainly occurred in intestinal feces and that deglycosylation, demethylation, and hydroxylation were the main pathways of their metabolism. HPLC quantitative analysis of the transformation solution at different time points showed that AGs were transformed into secondary glycosides [cycloastragenol-6-glucoside (CAG-6-glucoside)] and aglycones [cycloastragenol (CAG)] through a deglycosylation reaction. Analysis of the pharmacological activity showed that the anti-inflammatory and antioxidant activities of the metabolites were associated with the levels of the corresponding aglycones. Further, metabolic profiles of the TAGs were constructed. Overall, this study revealed the metabolic process of AGs in the intestine, providing guidance for the metabolism and pharmacological effects of other saponins.

Preventive Effect of 6-shogaol on D-galactosamine Induced Hepatotoxicity Through NF-?B/MAPK Signaling Pathway in Rats

This analysis aims to see whether 6-shogaol could protect rats against D-galactosamine (D-GalN)-induced Hepatotoxicity. The Wistar rats were divided into four groups (n=6). Group 1 received a standard diet, Group 2 received an oral administration of 6-shogaol (20 mg/kg b.wt), Group 3 received an intraperitoneal injection of D-GalN (400 mg/kg b.wt) on 21st day, and Group 4 received an oral administration of 6-shogaol (20mg/kg b.wt) for 21 days and D-GalN (400 mg/kg b.wt) injection only on 21st day. The hepatic marker enzymes activity, lipid peroxidative markers level increased significantly and antioxidant activity/level significantly reduced in D-GalN-induced rats. 6-shogaol Pretreatment effectively improves the above changes in D-GalN-induced rats. Further, inflammatory marker expression and MAPK signaling molecules were downregulated by 6-shogaol. These findings showed that 6-shogaol exerts hepatoprotective effects via the enhanced antioxidant system and attenuated the inflammation and MAPK signaling pathway in D-GalN-induced rats.

Stepwise Targeted Matching Strategy for Comprehensive Profiling of Xanthohumol Metabolites In Vivo and In Vitro Using UHPLC-Q-Exactive Orbitrap Mass Spectrometer

Xanthohumol (XN), a natural prenylated flavonoid extracted and isolated from the hop plant (Humulus lupulus), possesses diverse pharmacological activities. Although the metabolites of XN have been investigated in the previous study, a comprehensive metabolic profile has been insufficient in vivo or in vitro until now. The current study was aimed at systematically elucidating the metabolic pathways of XN after oral administration to rats. Herein, a UHPLC-Q-Exactive Orbitrap MS was adopted for the potential metabolites detection. A stepwise targeted matching strategy for the overall identification of XN metabolites was proposed. A metabolic net (53 metabolites included) on XN in vivo and in vitro, as well as the metabolic profile investigation, were designed, preferably characterizing XN metabolites in rat plasma, urine, liver, liver microsomes, and feces. On the basis of a stepwise targeted matching strategy, the net showed that major in vivo metabolic pathways of XN in rats include glucuronidation, sulfation, methylation, demethylation, hydrogenation, dehydrogenation, hydroxylation, and so on. The proposed metabolic pathways in this research will provide essential data for further pharmaceutical studies of prenylated flavonoids and lay the foundation for further toxicity and safety studies.

[Determination of misoprostol in workplace air by high performance liquid chromatography]

Objective: To establish a high performance liquid chromatography method for the determination of misoprostol in workplace air. Methods: From February to August 2021, the misoprostol in the workplace air was collected by glass fiber filter membrane, and theeluent was separated by C18 liquid chromatography column, determined by UV detector, and quantified by external standard method. Results: The quantitative lower limit of misoprostol determination method was 0.05 μg/ml, and the lowest quantitative concentration was 1.4 μg/m(3) (calculated by collecting 75 L air sample). The concentration of misoprostol has a good linear relationship between 0.05 to 10.00 μg/ml. The relative coefficient was 0.9998. The regression equation of the standard working curve was y=495759x-45257. The range of average recovery rates were from 95.5% to 102.8%. The intra-assay precision of the method was 1.2%-4.6%, and the inter-assay precision was 2.0%-5.9%. The samples could be stored stably for 7 days at 4 ℃. Conclusion: The high performance liquid chromatography method for the determination of misoprostol has high sensitivity, good specificity and simple procedure of sample pretreatment. It is suitable for the detection of misoprostol in the workplace air.

Preoperative prediction of microvascular invasion and perineural invasion in pancreatic ductal adenocarcinoma with 18F-FDG PET/CT radiomics analysis

AIM

To develop and validate a predictive model based on 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) radiomics features and clinicopathological parameters to preoperatively identify microvascular invasion (MVI) and perineural invasion (PNI), which are important predictors of poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Preoperative ¹⁸F-FDG PET/CT images and clinicopathological parameters of 170 patients in PDAC were collected retrospectively. The whole tumour and its peritumoural variants (tumour dilated with 3, 5, and 10 mm pixels) were applied to add tumour periphery information. A feature-selection algorithm was employed to mine mono-modality and fused feature subsets, then conducted binary classification using gradient boosted decision trees.

RESULTS

For MVI prediction, the model performed best on a fused subset of ¹⁸F-FDG PET/CT radiomics features and two clinicopathological parameters, with an area under the receiver operating characteristic curve (AUC) of 83.08%, accuracy of 78.82%, recall of 75.08%, precision of 75.5%, and F1-score of 74.59%. For PNI prediction, the model achieved best prediction results only on the subset of PET/CT radiomics features, with AUC of 94%, accuracy of 89.33%, recall of 90%, precision of 87.81%, and F1 score of 88.35%. In both models, 3 mm dilation on the tumour volume produced the best results.

CONCLUSIONS

The radiomics predictors from preoperative ¹⁸F-FDG PET/CT imaging exhibited instructive predictive efficacy in the identification of MVI and PNI status preoperatively in PDAC. Peritumoural information was shown to assist in MVI and PNI predictions.

Prevalence and influencing factors of anaemia among pregnant women in rural areas of Northwestern China

OBJECTIVES

Anaemia during pregnancy is a significant public health problem that adversely impacts both the mother and foetus. However, the factors influencing maternal anaemia in deprived areas of Northwestern China have not yet been thoroughly investigated. This study aimed to describe the prevalence and potential influencing factors of anaemia among expectant mothers in rural areas of Northwestern China.

STUDY DESIGN

This was a cross-sectional survey.

METHODS

A cross-sectional survey of 586 expectant mothers was conducted to investigate the prevalence of anaemia, prenatal healthcare coverage, dietary diversity and nutrient supplementation intake. The study population was selected from the sample areas using a random sampling method. Data were collected through a questionnaire, and haemoglobin concentrations were measured by a capillary blood test.

RESULTS

The results show that 34.8% of the study population were anaemic, with 13% having moderate-to-severe anaemia. The results of the regression analysis showed that diet was not significantly associated with haemoglobin concentrations or the prevalence of anaemia. However, regular prenatal healthcare attendance was found to be an important influencing factor for both haemoglobin concentration (β = 3.67, P = 0.002) and the prevalence of anaemia (odds ratio = 0.59, P = 0.011).

CONCLUSIONS

Pregnant women receiving regular prenatal care were less likely to be anaemic; thus, it is essential to implement strategies to improve attendance at maternal public health services to reduce the prevalence of maternal anaemia.

First Report of Cobweb Disease in Auricularia cornea var. Li. Caused by Hypomyces mycophilus in China

Auricularia cornea var. Li. is a natural mutation strain of A. cornea which has been preferred by consumers for its white colour, good taste and pharmacological properties (Rebecca et al. 2020). In October 2021, a disease with symptoms similar to that of cobweb disease (Carrasco et al. 2017) was observed in A. cornea var. Li. in four mushroom farms in Fangshan District (115.83°E, 39.55°N), Beijing, China, infecting 20% of the fruiting bodies (Fig. 1A-D). White cottony mycelia formed typically on the casing soil and they gradually spread to the stipes and pileus, covering the whole fruiting body, which eventually died and lost commodity value. Cultures were obtained by aseptically transferring the diseased fruiting bodies onto potato dextrose agar (PDA); they were deposited in the culture collection (ID: JZBQA3) of the Beijing Academy of Agriculture and Forestry Sciences, China. The colonies were floccose with aerial mycelium white. Purplish grey diffusing pigments occasionally formed on the reverse side of the plate at 25 °C (Fig. 2A-B). Conidiophores arising in aerial mycelium, indefinite in length, branches septate, each cell producing denticulate conidiogenous loci, each denticle bearing a single conidium. Conidia mostly oblong to ellipsoidal, smooth, (9.0-)9.9-17.0(-18.0)×(6.0-)6.9-10.2 μm (n = 60), 0~1 septate (Fig. 2C-E). Chlamydospores forming as lateral branches of hyphae were commonly observed, globose, ellipsoid or oblong, 14.8-22×14.7-19.6 μm, l/w = 1.0-1.3 (Fig. 2F-G). The morphological characteristics were consistent with that of Hypomyces mycophilus, whose anamorph was Cladobotryum polypori (Rogerson et al. 1993, Zeng et al. 2017). For further species identification, genomic DNA was extracted using the DNeasy Plant Mini Kit (Qiagen, USA). The internal transcribed spacer (ITS) regions and large subunit ribosomal RNA (LSU) genes were amplified using the primer pairs ITS1/ITS4 (White et al. 1990) and LROR/LR5 (Bhattacharya et al. 2000), respectively. The sequences were deposited in GenBank with accession numbers OP430530 and OP430531. BLAST nucleotide searches showed more than 99% homology with corresponding sequences of Hypomyces mycophilus HMAS 275554 and CBS 175.56. Phylogenetic trees based on ITS and LSU revealed that the strain JZBQA3 was grouped with H. mycophilus with high support value (Fig. 3). A in vivo pathogenicity test was performed using eight mushroom sticks with healthy fruiting bodies in triplicate. Each four sticks were sprayed with conidial suspension (108 spores/mL) of strain JZBQA3 or sterile distilled water, respectively, and maintained in an artificial climate chamber at 25-26°C. Cobweb-like characteristics were observed on the fruiting bodies treated with the JZBQA3 conidial suspension 2-3 days after inoculation, while those treated with sterile distilled water remained symptomless (Fig. 4 A-B). The same pathogen was re-isolated and confirmed from the infected fruiting bodies by integrated analysis of morphological characteristics and gene sequencing data, fulfilling Koch's postulates. Hypomyces mycophilus was first reported on Trametes versicolor in North Carolina (Rogerson et al. 1993), and is the causal agent of cobweb diseases on Auricularia heimuer (Zhang et al. 2023). To our knowledge, this is the first report of cobweb disease caused by H. mycophilus in A. cornea var. Li. This finding is a valuable contribution to the knowledge of cobweb disease development in edible fungi.

Comprehensive Profiling of Mangiferin Metabolites In Vivo and In Vitro Based on the "Drug Metabolite Clusters" Analytical Strategy

Mangiferin, a natural flavonoid compound with multiple biological activities (e.g., anti-inflammatory, anti-oxidant, anti-diabetic, and anti-tumor), has gained increased research interest in recent years. Nevertheless, the metabolic processing of mangiferin has not been fully investigated. In this study, a rapid and efficient analytical strategy named "Drug Metabolite Clusters" was applied for comprehensive profiling of mangiferin metabolites in rat plasma, urine, and feces samples in vivo following oral administration and liver microsomes in vitro. First, the biological samples were pretreated with methanol, acetonitrile, and solid phase extraction (SPE) for further liquid chromatography-mass spectrometry (LC-MS) analysis. Second, the raw data were acquired using ultra-high performance liquid chromatography quadrupole exactive orbitrap high-resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap HRMS) under the positive and negative full-scan/dd MS² modes. Third, mangiferin and its basic metabolites (norathyriol, trihydroxyxanthone, and dihydroxyxanthone) were selected as mangiferin metabolite cluster centers by referring to the relevant literature. Subsequently, according to the pyrolysis law of mass spectrometry, literature reports, and reference material comparison, especially the diagnostic product ions (DPIs), the candidate metabolites were accurately preliminarily identified, and mangiferin metabolite clusters based on metabolite cluster center changes were formed. As a result, a total of 67 mangiferin metabolites (mangiferin included) were detected, including 29 in plasma, 48 in urine, 12 in feces, and 6 in liver microsomes. Among them, trihydroxyxanthones were first detected in rat urine samples after oral mangiferin. We found that mangiferin mainly underwent deglucosylation, dehydroxylation, methylation, glucuronidation, sulfation, and other composite reactions in rats. Herein, we have elucidated the metabolites and metabolic pathways of mangiferin in vivo and in vitro, which provided an essential theoretical basis for further pharmacological studies of mangiferin and a comprehensive research method for the identification of drug metabolites.

Activation cross sections for reactions induced by 14 MeV neutrons on natural titanium

Cross sections for the neutrons around 14 MeV interaction with natural titanium were precisely measured by neutron activation and off-line measurement technique. The fast neutrons were produced by ³H(d,n)⁴He reaction and the neutron energy was obtained by using the cross section ratio method of ⁹⁰Zr(n,2n)⁸⁹Zr to ⁹³Nb(n,2n)^92mNb reactions. Experimental cross sections have been acquired for ^natTi(n,x)⁴⁶Sc, ^natTi(n,x)⁴⁷Sc, ⁵⁰Ti(n,x)⁴⁷Ca and ⁴⁸Ti(n,x)⁴⁸Sc reactions. The measured cross section data are compared with the experimental data available in the previous literature and evaluated nuclear data from the ENDF/B-VIII.0, JEFF-3.3, JENDL-5, BROND-3.1, CENDL-3.2 and FENDL-3.2b libraries. Furthermore, excitation functions for these reactions were calculated by using the theoretical model based on Talys-1.96 code with default and adjusted parameters. Within experimental error, evaluated nuclear data are mostly consistent with experimental data. The excitation function with adjusted parameters can roughly reproduce the experimental data.

Assessment of healthcare quality among village clinicians in rural China: the role of internal work motivation

INTRODUCTION

The quality of primary care is important for health outcomes among residents in China. There is evidence that internal work motivation improves the quality of healthcare provided by clinicians. However, few empirical studies have examined the relationship between internal work motivation and clinical performance among village clinicians in rural China. This study was performed to evaluate healthcare quality among village clinicians, then explore its relationships with internal work motivation among those clinicians.

METHODS

We collected survey data using a standardised patient method and a structured questionnaire. We observed 225 interactions between standardised patients and village clinicians from 21 counties in three provinces. We used logistic regression models to analyse the relationships between work motivation and healthcare quality, then conducted heterogeneity analysis.

RESULTS

Healthcare quality among village clinicians was generally low. There was a significantly positive correlation between internal work motivation and healthcare quality among village clinicians (P<0.1). Additionally, the positive effect of internal work motivation on healthcare quality was strongest among clinicians who received financial incentives and had a lighter workload (fewer patients per month) [P<0.1].

CONCLUSION

Healthcare quality among village clinicians requires urgent improvement. We recommend implementing financial incentives to stimulate internal work motivation among village clinicians, thus improving their clinical performance.

Bivalent intra-spike binding provides durability against emergent Omicron lineages: Results from a global consortium

The SARS-CoV-2 Omicron variant of concern (VoC) and its sublineages contain 31-36 mutations in spike and escape neutralization by most therapeutic antibodies. In a pseudovirus neutralization assay, 66 of the nearly 400 candidate therapeutics in the Coronavirus Immunotherapeutic Consortium (CoVIC) panel neutralize Omicron and multiple Omicron sublineages. Among natural immunoglobulin Gs (IgGs), especially those in the receptor-binding domain (RBD)-2 epitope community, nearly all Omicron neutralizers recognize spike bivalently, with both antigen-binding fragments (Fabs) simultaneously engaging adjacent RBDs on the same spike. Most IgGs that do not neutralize Omicron bind either entirely monovalently or have some (22%-50%) monovalent occupancy. Cleavage of bivalent-binding IgGs to Fabs abolishes neutralization and binding affinity, with disproportionate loss of activity against Omicron pseudovirus and spike. These results suggest that VoC-resistant antibodies overcome mutagenic substitution via avidity. Hence, vaccine strategies targeting future SARS-CoV-2 variants should consider epitope display with spacing and organization identical to trimeric spike.

Serial five-membered lactone ring ions in the treatment of Alzheimer's diseases-comprehensive profiling of arctigenin metabolites and network analysis

Arctigenin is a phenylpropanoid dibenzylbutyro lactone lignan compound with multiple biological functions. Previous studies have shown that arctigenin have neuroprotective effects in Alzheimer's disease (AD) models both in vivo and in vitro; however, its metabolism in vivo has not been studied. Most traditional analytical methods only partially characterize drug metabolite prototypes, so there is an urgent need for a research strategy that can fully characterize drug metabolites. In the present study, ions fishing with a serial five-membered lactone ring as a fishhook strategy based on ultrahigh-performance liquid chromatography-Q-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap MS) was utilised to characterise the metabolism of arctigenin, and the establishment of this strategy also solved the challenge of creating a comprehensive metabolic profile of neolignan. Based on the proposed strategy, a total of 105 metabolites were detected and characterised, 76 metabolites of which were found in rats and 49 metabolites in liver microsomes. These metabolites were postulated to be produced through oxidation, reduction, hydrolysis, and complex reactions. Subsequently, network pharmacology was utilized to elucidate the mechanism of arctigenin and its main metabolites against Alzheimer's disease, screening 381 potential targets and 20 major signaling pathways. The study on the comprehensive metabolism of arctigenin provides a holistic metabolic profile, which will help to better understand the mechanism of arctigenin in the treatment of Alzheimer's disease (AD) and also provide a basis for the safe administration of arctigenin.

Neutralizing antibodies from the rare convalescent donors elicited antibody-dependent enhancement of SARS-CoV-2 variants infection

Currently, neutralizing antibody and vaccine strategies have been developed by targeting the SARS-CoV-2 strain identified during the early phase of the pandemic. Early studies showed that the ability of SARS-CoV-2 RBD or NTD antibodies to elicit infection enhancement in vivo is still controversial. There are growing concerns that the plasma and neutralizing antibodies from convalescent patients or people receiving vaccines mediate ADE of SARS-CoV-2 variants infections in immune cells. Here, we constructed engineered double-mutant variants containing an RBD mutation and D614G in the spike (S) protein and natural epidemic variants to gain insights into the correlation between the mutations in S proteins and the ADE activities and tested whether convalescent plasma and TOP10 neutralizing antibodies in our laboratory mediated the ADE effects of these SARS-CoV-2 variants. We found that one out of 29 convalescent plasma samples caused the ADE effect of pandemic variant B.1.1.7 and that the ADE effect of wild-type SARS-CoV-2 was not detected for any of these plasma samples. Only one antibody, 55A8, from the same batch of convalescent patients mediated the ADE effects of multiple SARS-CoV-2 variants in vitro, including six double-mutant variants and four epidemic variants, suggesting that ADE activities may be closely related to the antibody itself and the SARS-CoV-2 variants' S proteins. Moreover, the ADE activity of 55A8 depended on FcγRII on immune cells, and the introduction of LALA mutations at the Fc end of 55A8 eliminated the ADE effects in vitro, indicating that 55A8LALA may be a clinical drug used to prevent SARS-CoV-2 variants. Altogether, ADE may occur in rare convalescent patients or vaccinees with ADE-active antibodies who are then exposed to a SARS-CoV-2 variant. These data suggested that potential neutralizing antibodies may need to undergo ADE screening tests for SARS-CoV-2 variants, which should aid in the future design of effective antibody-based therapies.

A Novel CTLA-4 affinity peptide for cancer immunotherapy by increasing the integrin αvβ3 targeting

Immune checkpoint inhibitors (ICIs) are changing all aspects of malignant tumour therapy as an immunotherapy subverter in oncology. However, the current ICIs might induce systemic immune activation in other tissues and organs since they are not tumour-specific, causing the immune system to attack some normal tissues and organs of the human body. The toxicity can also amplify greatly although combined immunotherapy for cancer has increased the curative efficacy. The LC4 peptide was modified to improve its tumour-targeting ability and reduce peripheral immune system activation, which was obtained through phage display peptide library screening and could block the CTLA-4/CD80 interaction. The LC4 peptide as a result, like other ICIs, exerts anti-tumour effects by refreshing T cell function, and also activates the peripheral immune system. We used the PLGLAG peptide as a linker at the C-terminal of LC4 to connect with a tumour-targeting peptide RGD to increase the tumour tissue targeting ability, and obtain LC4-PLG-RGD. Further experiments demonstrated that the anti-tumour LC4-PLG-RGD activity was better than LC4 in vivo, and the ability to activate the peripheral immune system was weakened. In conclusion, LC4-PLG-RGD can increase the ICIs tumour-targeting and reduce excessive peripheral tissue immune activation, thereby reducing the side effects of ICIs, while increasing their anti-tumour efficacy. This study confirmed that enhanced ICI tumour targeting can effectively reduce immune-related adverse reaction occurrence.

A potent neutralizing antibody provides protection against SARS-CoV-2 Omicron and Delta variants via nasal delivery

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still rapidly spreading worldwide. Many drugs and vaccines have been approved for clinical use show efficacy in the treatment and prevention of SARS-CoV-2 infections. However, the emergence of SARS-CoV-2 variants of concern (VOCs), such as Delta (B.1.617.2) and the recently emerged Omicron (B.1.1.529), has seriously challenged the application of current therapeutics. Therefore, there is still a pressing need for identification of new broad-spectrum antivirals. Here, we further characterized a human antibody (58G6), which we previously isolated from a patient, with a broadly authentic virus-neutralizing activity that inhibits the Delta and Omicron variants with half-maximal inhibitory concentrations (IC₅₀) of 1.69 ng/ml and 54.31 ng/ml, respectively. 58G6 shows prophylactic and therapeutic efficacy in hamsters challenged with the Delta and Omicron variants through nasal delivery. Notably, a very low dosage (2 mg/kg daily) of 58G6 efficiently prevented Omicron variant replication in the lungs. These advantages may overcome the efficacy limitation of currently approved neutralizing antibodies that can be administered only by intravenous injection. In general, 58G6 is a promising prophylactic and therapeutic candidate against current circulating VOCs and even future emerging mutants. To the best of our knowledge, 58G6 is one of the most potent neutralizing antibodies against Omicron, with a broader spectrum than those approved for clinical use. 58G6 could be developed as a nebulized therapy, which would be more cost effective and user friendly and enhance the clinical outcome compared to that obtained with direct nasal delivery.

Utilisation of village clinics in Southwest China: evidence from Yunnan Province

INTRODUCTION

Primary healthcare in rural China is underutilised, especially in village clinics in Southwest China. The aim of this study was to explore any relationships among the ethnicity of the healthcare provider, the clinical competence of the healthcare provider, and the utilisation of village clinics in Southwest China.

METHODS

This cross-sectional survey study involved 330 village healthcare providers from three prefectures in Yunnan Province in 2017. Multiple logistic regressions were adopted to investigate the utilisation of primary healthcare among different ethnic healthcare providers.

RESULTS

Primary healthcare utilisation was higher in village clinics where healthcare providers were Han Chinese than those where healthcare providers were ethnic minority (151 vs 101, P=0.008). The logistic regression analysis showed that clinical competence was positively associated with the utilisation of primary healthcare (odds ratio [OR]=1.49, 95% confidence interval [CI]=1.12-2.00; P=0.007) and that inadequate clinical competence of ethnic minority health workers may lead to a lag in the utilisation of primary healthcare (OR=0.45, 95% CI=0.23-0.89; P=0.022).

CONCLUSION

Our results confirm differences in the utilisation of primary healthcare in rural Yunnan Province among healthcare providers of different ethnicities. Appropriate enhancements of clinical competence could be conducive to improving the utilisation of primary healthcare, especially among ethnic minority healthcare providers.

[Screening and preliminary validation of biomarkers in sputum-negative pulmonary tuberculosis based on positron emission tomography/computed tomography and transcriptomics]

Objective: To screen and perform preliminary clinical validation of biomarkers of activity based on positron emission tomography/computed tomography (PET-CT) and transcriptomics in sputum-negative pulmonary tuberculosis lesion tissue. Methods: Nine patients with sputum-negative pulmonary tuberculosis treated surgically at the Shanghai Public Health Clinical Center for Thoracic Surgery from January 1, 2017 to December 31, 2019 were retrospectively collected as the discovery group, including four males and five females, aged 20-57 years (mean 36 years). All of the patients underwent PET-CT scanning before surgery, and the resected specimens were postoperatively classified according to preoperative PET-CT. The resected specimens were divided into areas with increased fluorodeoxyglucose (FDG) metabolism (SUVmax>3) and areas with normal FDG metabolism (SUVmax ≤ 3) according to the preoperative PET-CT performance. After sample processing, total RNA was extracted from the tissues of different regions, and then whole gene transcriptome sequencing was performed. Bioinformatics analysis of the two sets of data was performed to discover the expression profiles of the differences in whole gene transcriptome data between the two regions and to screen for candidate biomarkers. Eighty patients with sputum-negative pulmonary tuberculosis admitted to Shanghai Public Health Clinical Center from January 1, 2019 to January 1, 2021 were retrospectively collected as the validation group, including 37 males and 43 females, aged 20-62 years, with an average age of 39 years. The validation group was divided into a group with increased SUV (n=40) and a group without lesions on CT imaging (n=40). Enzyme-linked immunosorbent assay (ELISA) was used to determine the protein levels of candidate biomarkers in the peripheral plasma of patients. The effect of biomarkers was assessed using subject operating characteristic (ROC) curves. Student's t-test was used to determine whether the difference in protein levels between the two groups was statistically significant. Results: Bioinformatics analysis revealed that the expression levels of C1QB, CCL19, CCL5 and HLA-DMB correlated with the metabolic activity of sputum-negative tuberculosis lesion tissue. Further screening and validation by the validation group confirmed that the difference in C1QB protein levels in the peripheral plasma of patients was statistically significant between the group with increased SUV and the group without lesions on CT imaging [(3.55±0.34) mg/L vs. (2.75±0.21) mg/L, t=4.12, P<0.001]. And the ROC curve showed that the area under the curve for C1QB protein levels was 0.731, which had potential clinical value. Conclusion: The C1QB protein level can be used to assess the activity of lesions in patients with sputum-negative tuberculosis and is a potential biomarker.

POS0811 CHARACTERISTICS OF INTESTINAL MICROBIOTA AND ITS RELATIONSHIP WITH LYMPHOCYTE SUBSETS AND CYTOKINES IN PATIENTS WITH VASCULITIS

Background

Vasculitis include a group of autoimmune inflammatory diseases with clinical heterogeneous characterized by inflammation of vascular wall, inflammation of perivascular tissues, and cell-like necrosis[1]. Disorder of gut microbiota, which plays a crucial role in regulating immune cells such as Th1, Th17 and Treg, is associated with other autoimmune diseases[2], and may also be involved in the pathogenesis of vasculitis.

Objectives

To investigate the changes of intestinal microbiota and its correlation with peripheral lymphocyte subsets and inflammatory factors levels in patients with vasculitis.

Methods

Combined with clinical manifestations and laboratory examination, 33 patients with vasculitis who met the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides[3] and 33 of age- and gender- matched healthy controls (HCs) were selected from the Second Hospital of Shanxi Medical University. The demographic characteristics, general laboratory indicators such as erythrocyte sedimentation rate (ESR), C-reaction protein (CRP), levels of peripheral lymphocyte subpopulations and serum cytokines detected by modified flow cytometry. Fecal microbiota detected by 16S rRNA gene sequencing and compiled and processed using Qiime2 and OTU-profiling tables were collected and analyzed in this study.

Results

Compared with HCs, the richness and diversity of intestinal flora in patients with vasculitis tended to decrease with a statistically significant difference in β diversity (P = 0.025, Figure 1 A and B). More specifically, vasculitis patients had a lower frequency of Firmicutes while higher Proteobacteria and Bacteroidota at the phylum level (P < 0.001, Figure 1C). In vasculitis patients, the relative abundances of 23 bacteria differed from HCs at the genus level was all decreased, including Gemella, Anaeroglobus, Campylobacter, Fournierella, et al (P < 0.001, Figure 1D and E). More importantly, the relative abundance of Muribaculaceae were positively correlated with the absolute count of Th2 and the proportions of Th1 and CD4+T cells and negatively correlated with CRP and ESR, while relative abundance of [Eubacterium]_ventriosum were positively associated with the absolute number of Treg cells and negatively correlated with the percentages of Th2 and CD8+T cells (Figure 1F).

Figure 1.

Differences in α diversity (A), β diversity (B), phylum (C), genus (D), and microbial composition (E) between vasculitis patients and HC and correlation analysis between differential microflora and clinical data in patients with vasculitis (F).

Conclusion

Disturbance of intestinal flora, mainly manifested by decreased diversity and richness, may be involved in the occurrence and development of vasculitis by inducing disroders in lymphocyte subsets and cytokines. Consequently, further studies on the immune mechanisms and influencing factors of intestinal flora may provide new ideas for the diagnosis and treatment of the disease for vasculitis patients.

References

[1]Aierken X, Zhu Q, Wu T, et al. Increased Urinary CD163 Levels in Systemic Vasculitis with Renal Involvement[J]. Biomed Res Int, 2021, 2021: 6637235. DOI: 10.1155/2021/6637235.

[2]Zhang X, Zhang D, Jia H, et al. The oral and gut microbiomes are perturbed in rheumatoid arthritis and partly normalized after treatment[J]. Nat Med, 2015, 21(8): 895-905. DOI: 10.1038/nm.3914.

[3]Jennette JC, Falk RJ, Bacon PA, et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides[J]. Arthritis Rheum, 2013, 65(1): 1-11. DOI: 10.1002/art.37715.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No.82001740).

Disclosure of Interests

None declared

AB0202 GUT MICROBIOTA DYSBIOSIS WERE CLOSELY CORRELATED WITH LYMPHOCYTE SUBSETS AND CYTOKINES IN PATIENTS WITH INFLAMMATORY ARTHRITIS

Background

Inflammatory arthritis includes a group of chronic conditions, particularly rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA)[1].Growing evidences link gut microbiota dysbiosis with the development of inflammatory arthritis[2].

Objectives

The aim of this study was to discover the characters of microbiota in inflammatory arthritis patients and compare the relationship between the microbiota and peripheral lymphocyte subsets and cytokines.

Methods

Fecal samples were collected from 73 arthritis patients (13 PsA, 30 AS, 30 RA patients) and 140 sex- and age-matched healthy controls (HCs). The gut microbiota was studied by sequencing the V3-V4 variable regions of bacterial 16S rRNA genes by the Illumina Miseq PE300 system. Peripheral lymphocyte subsets in these participants were assessed by flow cytometry. Measures of disease activity such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) were recorded. Alpha and Beta diversity was assessed using results from QIIME2 and gut microbiome profiles were compared using linear discriminant analysis (LDA) effect size (LEfSe). R (version 4.0.1) was used for comparative statistics, using pearson correlation analysis to assess the correlation between the relative abundance of genus in the sample and clinical parameters.

Results

Compared with HCs, the richness of gut microbiota (ACE and Chao 1) was significantly lower (p < 0.05) in arthritis patients, and bacterial diversity including Shannon and Simpson indices (p < 0.001) was also significant in arthritis decreased (Figure 1A). β-diversity analysis based on Bray-curtis distance revealed significant differences in microbial communities between arthritis and HCs (Figure 1B, r=0.098, p=0.001, ANOSIM). In addition, compared with HCs at the genus level, 9 bacterial groups were significantly different in PsA (p < 0.05), 19 bacterial groups in AS (p < 0.05), and 17 bacterial groups in RA(p < 0.05) (Figure 1C). There was a significant positive correlation between CD4+T and Prevotella(p<0.01), T and Prevotella(p<0.05), Blautia(p<0.05) as well as Megamonas(p<0.05), Th17 and Prevotella(p<0.01), CD8+T and Megamonas(p<0.01), Th1 and Megamonas(p<0.05), Prevotella(p<0.01),Coprococcus(p<0.05), B and Erysipelotricbaceae_UCG-003(p<0.01), and Erysipelotricbaceae_UCG-003(p<0.01), Anaerostipes(p<0.01), CRP and Fusobacterium(p<0.05) as well as Roseburia(p<0.05). There were negative correlations between T and Erysipelotricbaceae_UCG-003 (p<0.05),CD8+T and Fusobacterium(p<0.01), CD4+T and Fusobacterium(p<0.05), NK and Fusicatenibacter(p<0.05).

Conclusion

The gut microbiota of patients with inflammatory arthritis differs from HC and also varies among individual arthritis, which was closely related to lymphocyte subsets.

References

[1]Wu X. Innate Lymphocytes in Inflammatory Arthritis[J]. Front Immunol, 2020, 11: 565275.DOI: 10.3389/fimmu.2020.565275

[2]Breban M. Gut microbiota and inflammatory joint diseases[J]. Joint Bone Spine, 2016, 83(6): 645-649.DOI: 10.1016/j.jbspin.2016.04.005

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

POS0745 GUT DYSBIOSIS ASSOCIATED WITH PERIPHERAL LYMPHOCYTES AND CYTOKINES IN PATIENTS WITH SJÖGREN’S SYNDROME

Background

Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by disorders of lymphocyte subpopulations with various cytokines and auto-antibodies1. Growing evidences suggest that gut microbiome dysbiosis may contribute to the development of pSS2.

Objectives

To investigate the alterations to the gut microbiome and the correlation with peripheral lymphocytes and serum cytokines as well as inflammatory factors in pSS patients.

Methods

A total of 101 pSS patients and 101 age- and sex- matched healthy controls (HCs) were enrolled in this study from The Second Hospital of Shanxi Medical University (Taiyuan, Shanxi, China). Patients fulfilled the 2019 ACR/EULAR classification criteria. We conducted 16S rRNA gene sequencing using fecal microbiota samples and analyzed the peripheral lymphocyte subsets by flow cytometry. Serum cytokines, erythrocyte sedimentation rate (ESR), C-reaction protein (CRP), unstimulated and stimulated whole saliva (UWS and SWS) secretion rate was also collected, respectively. Sequence data were compiled and processed using Qiime2 and OTU-profiling tables were constructed. Correlations between different taxa and gut microbiome, as well as clinical variables, were calculated by Spearman’s rank test.

Results

Patients with pSS exhibited a significant reduction in the richness and diversity of gut microbiota compared with those of HCs (Figure 1A-B, p < 0.05). Detailly, at the phylum level, pSS patients had a lower frequency of Firmicutes while higher Proteobacteria (Figure 1C, p < 0.05). Compared with HCs, 11 species of flora were discovered to be distinctly different at the genus level (p < 0.05). Patients presented fewer Faecalibacterium and Roseburia but more Lactobacillus (Figure 1D, p < 0.05). Lactobacillus negatively correlated with T cells (r=-0.407), CD8+T (r=-0.417) and Th2 (r=-0.323). There was a significant positive correlation between Faecalibacterium and IL-2(r=0.312), IFN-γ(r=0.338), TNF-α levels(r=0.322) (Figure 1E, p < 0.05). As for clinical disease measures, IL-6 increases were in line with ESR and CRP, while IL-2 levels inversely related to CRP. Additional UWS secretion rate and SWS secretion rate had negative correlation with ESR (Figure 1F, p < 0.05).

Conclusion

The structural disorder of gut microbiota was distinct in pSS which were associated with peripheral lymphocyte subsets and cytokines. Disorders of gut microbiota and immune systems may contribute to the occurrence and development of pSS.

References

[1]Mariette X, Criswell LA. Primary Sjogren’s Syndrome. N Engl J Med 2018;378(10):931-39. doi: 10.1056/NEJMcp1702514

[2]Trujillo-Vargas CM, Schaefer L, Alam J, et al. The gut-eye-lacrimal gland-microbiome axis in Sjogren Syndrome. Ocul Surf 2020;18(2):335-44. doi: 10.1016/j.jtos.2019.10.006

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

POS0330 DIFFERENCES IN GUT MICROBIOTA ASSOCIATED WITH LYMPHOCYTE SUBSETS, CYTOKINES AND DISEASE ACTIVITY IN ANKYLOSING SPONDYLITIS

Background

Ankylosing spondylitis (AS), a common chronic inflammatory disease, is a prototype of spondyloarthritis affecting sacroiliac joints and spine with or without peripheral arthritis and other systemic symptoms[1]. Environmental factors, especially microorganisms have been suggested to implicate with AS pathogenesis[2].

Objectives

Utilizing 16S rRNA genes sequencing on the feces of untreated AS patients and healthy controls (HCs), our study aimed to provide an in-depth understanding of AS gut microbiota and identifying a feasible diagnostic strategy for AS.

Methods

Fecal samples were collected from 62 AS patients and 62 age-and-gender- matched HCs. Microbial genome was extracted from approximately 250mg fresh fecal samples from all participants using QIAamp PowerFecal DNA Kit (Qiagen). The V3-V4 variable regions of bacterial 16S rRNA genes were sequenced with the Illumina Miseq PE300 system. QIIME2 based pipeline was used to process the raw sequence data. Alpha and beta diversities were assessed using result from QIIME2, and comparisons of gut microbiome profile were performed using linear discriminant analysis (LDA) effect size (LEfSe) to examine differences between AS and HCs. R (version 4. 0.1) was used for comparative statistics, and pearson’s correlation was used to assess the correlations between the relative abundances of bacterial genera and clinical parameters; correlations with p<0.05 were considered significant.

Results

AS for alpha-diversity, ACE and Chao1 indices were lower in AS compared with those HCs(Figure 1A, p<0.05), though no significant differences observed in Shannon and Simpson index. Bray curtis distance-based beta-diversity analysis revealed significant differences in the microbial community between AS and HCs (Figure 1B, p=0.003, ANOSIM). Fecal microbial communities in AS differed significantly from those in HCs, driven by higher abundances of Escherichia-Shigella, Turicibacter, Enterococcus, et al. and a lower abundance of Agathobacter, Roseburia, Eubacterium_eligens_group, et al (Figure 1C, p<0.05). There was a significant positive correlation between ESR and Klebsiella, Butyricicoccus, Roseburia, CRP and Faecalibacterium, Muribaculaceae, ASDAS-CRP score and Faecalibacterium, Ruminococcus, total lymphocyte cells and Agathobacter, Ruminococcus, T cell and Agathobacter, CD4+T cell and Agathobacter, B cell and Agathobacter, Streptococcus, Th1 and Prevotella, CAG−352, Th2 and Agathobacter, Th17 and Prevotella, Agathobacter, IL-2 and Agathobacter, IL-4 and Agathobacter, IL-6 and Lachnospiraceae_UCG−004, Muribaculaceae, IL-17 and Eubacterium_hallii_group, IFN-gama and Phascolarctobacterium.There were negative correlations between total lymphocytes and Escherichia−Shigella, CD4+T cell and Enterobacteriaceae, Th2 cell and Escherichia−Shigella, IL-10 and CAG−352, Ruminococcus (Figure 2, p<0.05).

Figure 1.

Feature of gut microbiota in AS patients and HCs. (A) Alpha-diversity assessed by richness (Chao1, ACE) and diversity (Shannon, Simpson), Median estimates compared across cohorts. (B) PCoA plot based on the Bray curtis distance of gut microbiota samples from AS patients vs. HC group(p=0.003, ANOSIM). (C) Panel demonstrated the average relative abundance of different genus in AS and HCs. (D) Distribution of gut microbiota at genus level.

Figure 2.

Correlations between the relative abundance of significantly different bacteria and clinical variables. *p<0.05, **p < 0.01, ***p <0 .001, ****p < 0.0001.

Conclusion

Human gut microbiome in patients with AS differed from that of the HCs. Characters of bacteria communities were associated with disease activity.

References

[1]Simone D, Al Mossawi M H, Bowness P. Progress in our understanding of the pathogenesis of ankylosing spondylitis [J]. Rheumatology (Oxford), 2018, 57(suppl_6): vi4-vi9.

[2]Zhou C, Zhao H, Xiao X Y, et al. Metagenomic profiling of the pro-inflammatory gut microbiota in ankylosing spondylitis [J]. J Autoimmun, 2020, 107(102360.

Acknowledgements

This project was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

AB0492 INTESTINAL MICROBIOLOGICAL DISORDER CLOSELY ASSOCIATED WITH PERIPHERAL LYMPHOCYTE SUBSETS AND CYTOKINES IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by widespread inflammation and tissue damage in multiple organs[1]. Microbiome is one of environmental factors that has been suggested to contribute to the occurrence and development of SLE[2].

Objectives

This study aims to the understanding of the pathogenesis of SLE from the perspective of intestinal microorganisms and investigate the associations between flora and peripheral lymphocyte subpopulations and cytokines in SLE patients.

Methods

Fecal samples were collected from 96 patients with SLE, and 96 sex-and age-matched healthy controls (HCs). The gut microbiota were investigated via 16s rRNA sequencing and the peripheral T lymphocyte subsets of these participants were assessed by flow cytometry. Indicators of disease activity such as erythrocyte sedimentation rate (ESR), C-reaction protein (CRP), complement C3 and C4 were recorded. Differential abundance analysis was carried out using the edgeR algorithm. The Wilcoxon rank-sum test was used to compare alpha diversity indices, bacterial abundances, and the F/B ratio between groups. R (version 4.0.1) was used for comparative statistics, and pearson’s correlation analysis was used to assess the correlations between the relative abundances of bacterial genera and serum levels of ESR, CRP, C3 and C4 in the samples; correlations with p < 0.05 were considered significant.

Results

The alpha estimators of richness (ACE and Chao 1) were significantly reduced in SLE feces samples compared with those of HCs (p < 0.0001). Bacterial diversity estimators, including the Shannon (p < 0.001) and Simpson’s (p < 0.01) indices, were also significantly lower in SLE (Figure 1A-D). The microbial community structures of the SLE and HCs could be separated by unweighted UnFrac-based principal coordinates analysis (PCoA) (R = 0.186, and p = 0.001; Figure 1E). Significant differences in gut microbiota composition between SLE and HCs were found using the edgeR algorithm. Compared with HCs, 24 species of flora were discovered to be distinctly different(p < 0.05). Moreover, there was a significant positive correlation between Tregs and Corynebacterium(p < 0.05), CD8+T and Corynebacterium (p < 0.05), CD4+T and Corynebacterium (p < 0.05), T and Corynebacterium (p < 0.05), Th1 and Escherichia−Shigella (p < 0.01), Th2 and Dielma (P<0.001) as well as Eubacterium eligens group (p < 0.05), NK and Faecalibacterium (p < 0.01). as well as Corynebacterium (p < 0.001), IL-6 and Coprococcus (p < 0.05), IL-10 and Eubacterium eligens group (p < 0.001) as well as Veillonella (p < 0.05). and Lachnospira (p < 0.01). As for clinical disease measures, there were positive correlations between CRP and Eubacterium ventriosum (p < 0.05). and Coprococcus (p < 0.05), C4 and the abundance of Corynebacterium (p < 0.05) (Figure 1F).

Conclusion

Patients with gut dysbiosis that mainly characterized by reduced the diversity and impaired abundance of the intestinal flora. Abnormality of T cell subsets and cytokines, especially the level of CD4+T, CD8+T, NK, Treg, Th, IL-6 and IL-10 cells contributes to the occurrence and progression of SLE, which may be related to the disturbance of gut microbiota. The discovery of the associated intestinal microbiota of SLE may provide a new idea for treatment.

References

[1]Fava A, Petri M. Systemic lupus erythematosus: diagnosis and clinical management. J Autoimmun. (2019) 96:1–13. 10.1016/j.jaut.2018.11.001

[2]He Z, Shao T, Li H, Xie Z, Wen C: Alterations of the gut microbiome in Chinese patients with systemic lupus erythematosus. Gut pathogens 2016, 8:64.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

POS0556 ALTERATION OF THE GUT MICROBIOTA IN CHINESE POPULATION WITH RHEUMATOID ARTHRITIS

Background

Rheumatoid arthritis (RA) is an aggressive immune-mediated joint disease characterized by synovial proliferation and inflammation, cartilage destruction, and joint destruction. Growing evidences suggests a chronic inflammatory response induced by gut microbiome critically contribute to the development of rheumatoid arthritis.

Objectives

The aim of this study was to evaluate and quantify differences in the composition of gut microbiota in RA patients and investigate the associations between flora and clinical variables in RA patients.

Methods

Fecal samples from 145 RA patients and 145 age- and gender- matched healthy controls (HCs) were collected for bacterial 16S rRNA genes sequencing. The alpha-diversity, beta-diversity and the microbial composition (at the phylum and genus level) analysis of the gut microbiome were used to define the difference of gut microbiota profiles between RA patients and HCs. The peripheral lymphocytes of these patients were assessed by flow cytometry, and inflammatory biomarkers (ESR, CRP), auto-antibodies(ACPA, MCV) and cytokines measured by ELISA were recorded. Correlations between different taxa and clinical variables, were calculated by Spearman’s rank test.

Results

Consistent with trends observed for diversity, patients with RA had a lower richness compared with those of HCs (p < 0.01, Figure 1a), suggesting gut microbiome was markedly less diverse in composition in RA. Bray curtis distance-based beta diversity analysis revealed significant differences in the microbial community between RA and HCs (ANOSIM, R2=0.061, p=0.001, Figure 1b). Ten selected taxonomic biomarkers at different phylogenetic levels showed great discriminant ability, with Log10 LDA score > 4.0 (Figure 1e-g). Detailly, at the phylum level, RA patients had a lower frequency of Firmicutes while higher Proteobacteria. RA patients presented fewer Faecalibacterium but more Escherichia_Shigella at the genus level (Figure 1c-d). PICRUSt analysis found that in the KEGG pathways, the microbial gene functions related to Propanoate metabolism were higher in the fecal microbiome of RA patients (Figure 1h). Escherichia_Shigella positively correlated with ACPA antibodies (r=0.176, p < 0.05) and IL-4 (r=0.204, p < 0.05, Figure 1i), wheras Faecalibacterium as a probiotic showed no significant correlation with our clinical measures.

Figure 1.

Conclusion

Specific gut microbiota played an important role in the pathogenesis of RA, which may aid in the diagnosis or determination of the susceptibility of individuals to RA via detection of the gut microbiome.

References

[1]de Oliveira GLV, Leite AZ, Higuchi BS, et al. Intestinal dysbiosis and probiotic applications in autoimmune diseases. Immunology 2017;152(1):1-12. doi: 10.1111/imm.12765

[2]Chen J, Wright K, Davis JM, et al. An expansion of rare lineage intestinal microbes characterizes rheumatoid arthritis. Genome Med 2016;8(1):43. doi: 10.1186/s13073-016-0299-7

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared.

POS1153 CHARACTERISTICS OF GUT MICROBIOME AND THEIR ASSOCIATIONS WITH PERIPHERAL LYMPHOCYTE SUBPOPULATIONS AND CYTOKINES IN RHEUMATOID ARTHRITIS PATIENTS COMPLICATED WITH OSTEOPOROSIS

Background

Osteoporosis(OP) is one of the major comorbidities of rheumatoid arthritis(RA) which is associated with immune disorders[1]. The gut microbiota has been highlighted to be an important environmental factor to influence immune system in maintaining bone health and regulating bone remodeling[2]. However, the alterations of intestinal flora and its relationship with immune system in RA patients with OP are unclear.

Objectives

To investigate the characteristics of gut microbiome as well as the associations between flora and peripheral lymphocyte subpopulations and cytokines in rheumatoid arthritis patients complicated with osteoporosis.

Methods

Total 28 RA patients were divided into 14 RA-non-OP and 14 gender- and age-matched RA-OP groups according to their bone mineral density (BMD) and the history of fragility fracture. Gut microbiota of participants were investigated by 16s rRNA and peripheral lymphocyte subsets and cytokines were assessed via flow cytometry. Indicators like erythrocyte sedimentation rate (ESR), C-reaction protein (CRP), anti-cyclic citrullinated peptide antibody (ACPA) and anti-mutated citrullinated vimentin (MCV) antibody were recorded meanwhile. Alpha diversity (ACE, Chao1, Simpson, Shannon) and beta diversity indices were analyzed using QIIME2. Biomarker species were recognized based on STEMP. Spearman analysis was adopted for correlation of two variables. All P-values reported herein were two-tailed and P-value<0.05 was taken as statistically significant.

Results

The alpha-diversity have no significant difference between RA-non-OP and RA-OP groups (P >0.05, Figure 1A). The community structure of microflora differed between two groups (P <0.05, Figure 1B). As for the composition of intestinal flora at genus level, Faecalibacterium, Proteus, Catenibacterium, Enterobacter and Erysipelatoclostridium in RA-OP group as well as Lachnospiraceae_ND3007_group, Parasutterella, Megasphaera, Tyzzerella, UCG-005, Clostridium_sensu_stricto_1, UCG-002, Lachnospiraceae_NK4A136_group, Christensenellaceae_R-7_group, Prevotella, Parabacteroides in RA-non-OP group were significantly increased (Figure 1C). There were positive correlations between Lachnospiraceae_NK4A136_group and the level of T, Th1 and Th17 cells, but negative relevance with ESR, CRP and IL-10 (P <0.05). The relative abundance of Faecalibacterium was negatively correlated with IL-2, IL-4, TNF-α and positively with MCV (P <0.05). Clostridium_sensu_stricto_1 and Lachnospiraceae_ND3007_group were negatively correlated with ACPA and MCV respectively as well as IL-2 (P <0.05, Figure 1D-E).

Conclusion

Abnormality of immune system may contribute directly or indirectly to OP in RA, which may be related to the disturbance of gut microbiota.

References

[1]Horta-Baas G, Romero-Figueroa MDS, Montiel-Jarquín AJ, et al. Intestinal Dysbiosis and Rheumatoid Arthritis: A Link between Gut Microbiota and the Pathogenesis of Rheumatoid Arthritis. J Immunol Res. 2017;2017:4835189.

[2]Raterman HG, Bultink IE, Lems WF. Osteoporosis in patients with rheumatoid arthritis: an update in epidemiology, pathogenesis, and fracture prevention. Expert Opin Pharmacother. 2020 Oct;21(14):1725-1737.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

AB0844 Characterizing Gut Microbial Enterotypes in undifferentiated spondyloarthritis

Background

The presence of dysbiosis in the gut microbiome is responsible for the initiation of autoinflammatory and autoimmune diseases. However, such dysbiosis is difficult to characterize in sweeping generalization owing to the high dimensional complexity of the gut microbiota.

Objectives

This study designed to characterize the gut microbial enterotype in patients with undifferentiated spondyloarthritis (USpA) from lower dimensionality and describe the dysbiosis.

Methods

The Fecal samples of 105 patients were diagnosed with USpA and gender- and age- matched 105 healthy controls (HC) were included in the intestinal microbiota composition analyses via Illumina sequencing of bacterial 16S rRNA genes. Microbiota-derived clustering was performed using Dirichlet multinomial mixtures (DMM) modeling. To identify discriminative features in abundance between enterotypes, the Linear Discriminant Analysis Effect Size (LEfSe) algorithm was used with the online interface Galaxy (Log10 LDA score > 4.0). The phyloseq R package to compute alpha diversity (ACE, Chao1, Shannon and Simpson indices), beta diversity (Bray-Curtis dissimilarity) and the microbial composition (at the genus level) to describe the richness and diversity of the microbiota between two enterotypes.

Results

As showed in Figure 1A and C, by evaluating the Laplace approximation to the negative log mode, 2 distinctly enterotypes were identified in the USpA and HC microbiota dataset. LEfSe Analysis indicated the distinctive abundant microbial clades between the 2 enterotypes (LDA score >4) in both the USpA and HC group respectively. At the genus level, Faecalibacterium and Prevotella was the driving genus of enterotype 1 and Bacteroides contributed to enterotype 2 (Figure 1B, D). The alpha-diversity and beta diversity between the distinctive enterotypes was highly significantly different (P < 0.01, Figure 1E, F). Distinct bacterial profiles were also observed in enterotype 1 and 2 (Figure 1G). Interestingly, no significant differences were found between USpA patients and HC for the corresponding same intestinal type. This may be because USpA was at a comparatively early stage of spondyloarthritis (SpA).

Conclusion

Two significantly distinct bacterial microbiota structures existed in the USpA patients which was consistent with the general healthy population.

References

[1]Belkaid Y, Hand TW: Role of the microbiota in immunity and inflammation. Cell 2014, 157(1):121-141.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared

OP0087 INTEGRATED SYSTEMS ANALYSIS OF THE GUT MICROBIOTA PHENOTYPES IN THE RHEUMATOID ARTHRITIS

Background

Patients with rheumatoid arthritis (RA) displays extreme dysbiosis in microbiota. However, such dysbiosis is difficult to characterize owing to the high dimensional complexity of the gut microbiota1,2.

Objectives

The aim of this study was to discover the enterotype characters of intestinal flora in RA.

Methods

Fecal samples from 145 RA patients were collected for bacterial 16S rRNA genes sequencing. Mathematical modeling using Dirichlet multinomial mixtures (DMM) was applied to describe the variability in the microbiome data and cluster samples into enterotypes. The alpha-diversity, beta-diversity and the microbial composition analysis of the gut microbiome were used to define the difference of gut microbiota profiles between different enterotypes. The nonredundant taxonomic biomarkers for each enterotype were selected by using LEfSe. Inflammatory biomarkers (ESR, CRP), auto-antibodies(ACPA, MCV), peripheral lymphocytes subsets and cytokines were analyzed in our cohort using the Kruskal-Wallis test.

Results

Laplace approximation of DMM indicated two significantly distinct bacterial microbiota structures (RAE1 and RA E2) existed in the dataset (Figure 1a). Principal co-ordinates analyses confirmed that these two microbiota states explained a reasonable proportion of observed variance in microbiota composition(ANOSIM R2 = 0.267, p = 0.001; Figure 1b), with distinct bacterial genus distribution of in each enterotype (Figure 1c). RA E1 were primarily dominated by Prevotella while RA E2 by Bacteroides. Interestingly, Chao1, ACE, Shannon and Simpson revealed a higher alpha diversity in Prevotella-enriched enterotype (p< 0.001, Figure 1d). Fourteen selected taxonomic biomarkers at different phylogenetic levels showed great discriminant ability, with Log10 LDA score > 4.0 (Figure 1e-g). Further, inflammatory biomarkers (ESR, CRP) and auto-antibodies(ACPA, MCV) as well as the number of T, B and CD4+T, Th1, Th2, Th17, and Treg were consistent in RA E1 and RA E2 (p > 0.05, Figure 2h). But CD8+T were significantly higher in RA E2 than in RA E2 (p < 0.05).

Conclusion

Despite RA gut microbiota being of different dysbiosis, two patterns of dysbiosis, designated as RA-enterotypes, were predominant among the RA patient cohort. RA E2 exhibited a loss of Prevotella but a growth of Bacteroides, while RA E1 presented the opposite results.

References

[1]Arumugam M, Raes J, Pelletier E, et al. Enterotypes of the human gut microbiome. Nature 2011;473(7346):174-80. doi: 10.1038/nature09944

[2]Costea PI, Hildebrand F, Arumugam M, et al. Enterotypes in the landscape of gut microbial community composition. Nat Microbiol 2018;3(1):8-16. doi: 10.1038/s41564-017-0072-8

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 82001740).

Disclosure of Interests

None declared.

Structures of Omicron spike complexes and implications for neutralizing antibody development

The emergence of the SARS-CoV-2 Omicron variant is dominant in many countries worldwide. The high number of spike mutations is responsible for the broad immune evasion from existing vaccines and antibody drugs. To understand this, we first present the cryo-electron microscopy structure of ACE2-bound SARS-CoV-2 Omicron spike. Comparison to previous spike antibody structures explains how Omicron escapes these therapeutics. Secondly, we report structures of Omicron, Delta, and wild-type spikes bound to a patient-derived Fab antibody fragment (510A5), which provides direct evidence where antibody binding is greatly attenuated by the Omicron mutations, freeing spike to bind ACE2. Together with biochemical binding and 510A5 neutralization assays, our work establishes principles of binding required for neutralization and clearly illustrates how the mutations lead to antibody evasion yet retain strong ACE2 interactions. Structural information on spike with both bound and unbound antibodies collectively elucidates potential strategies for generation of therapeutic antibodies.

Updating species diversity of Colletotrichum, with a phylogenomic overview

The genus Colletotrichum includes important plant pathogens, endophytes, saprobes and human pathogens. Even though the polyphasic approach has facilitated Colletotrichum species identification, knowledge of the overall species diversity and host distribution is largely incomplete. To address this, we examined 952 Colletotrichum strains isolated from plants representing 322 species from 248 genera, or air and soil samples, from 87 locations in China, as well as 56 strains from Saudi Arabia, Thailand, Turkey, and the UK. Based on morphological characteristics and multi-locus phylogenetic analyses, the strains were assigned to 107 species, including 30 new species described in this paper and 18 new records for China. The currently most comprehensive backbone tree of Colletotrichum, comprising 16 species complexes (including a newly introduced C. bambusicola species complex) and 15 singleton species, is provided. Based on these analyses, 280 species with available molecular data are accepted in this genus, of which 139 have been reported in China, accounting for 49.6 % of the species. Colletotrichum siamense, C. karsti, C. fructicola, C. truncatum, C. fioriniae, and C. gloeosporioides were the most commonly detected species in China, as well as the species with the broadest host range. By contrast, 76 species were currently found to be associated with a single plant species or genus in China. To date, 33 Colletotrichum species have been exclusively reported as endophytes. Furthermore, we generated and assembled whole-genome sequences of the 30 new and a further 18 known species. The most comprehensive genome tree comprising 94 Colletotrichum species based on 1 893 single-copy orthologous genes was hence generated, with all nodes, except four, supported by 100 % bootstrap values. Collectively, this study represents the most comprehensive investigation of Colletotrichum diversity and host occurrence to date, and greatly enhances our understanding of the diversity and phylogenetic relationships in this genus.

A Highly Conserved Peptide Vaccine Candidate Activates Both Humoral and Cellular Immunity Against SARS-CoV-2 Variant Strains

Facing the imminent need for vaccine candidates with cross-protection against globally circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutants, we present a conserved antigenic peptide RBD9.1 with both T-cell and B-cell epitopes. RBD9.1 can be recognized by coronavirus disease 2019 (COVID-19) convalescent serum, particularly for those with high neutralizing potency. Immunization with RBD9.1 can successfully induce the production of the receptor-binding domain (RBD)-specific antibodies in Balb/c mice. Importantly, the immunized sera exhibit sustained neutralizing efficacy against multiple dominant SARS-CoV-2 variant strains, including B.1.617.2 that carries a point mutation (S^L452R) within the sequence of RBD9.1. Specifically, S^Y451 and S^Y454 are identified as the key amino acids for the binding of the induced RBD-specific antibodies to RBD9.1. Furthermore, we have confirmed that the RBD9.1 antigenic peptide can induce a S^448-456 (NYNYLYRLF)-specific CD8⁺ T-cell response. Both RBD9.1-specific B cells and the S^448-456-specific T cells can still be activated more than 3 months post the last immunization. This study provides a potential vaccine candidate that can generate long-term protective efficacy over SARS-CoV-2 variants, with the unique functional mechanism of activating both humoral and cellular immunity.

[Influence of guided bone regeneration on marginal bone loss of implants in the mandible posterior region: a 10-year retrospective cohort study]

Objective: To investigate the effect of guided bone regeneration (GBR) on marginal bone loss (MBL) in the region of the mandibular posterior tooth by using a retrospective cohort study, in order to provide reference for clinical practice. Methods: The research subjects were patients who received dental implants from October 2008 to June 2011 in the region of the mandibular posterior tooth at the Department of Oral Implantology, School of Stomatology, The Fourth Military Medical University. According to whether GBR was performed or not and the time of implant insertion, the patients were divided into the controls group (patients without bone grafting), simultaneous GBR implantation group, and delayed GBR implantation group. On this basis, the MBL was measured according to radiographs by comparing the marginal bone level from that of immediate postoperation 10 years ago. General data was collected and compared among groups, including modified plaque index (mPI), modified sulcus bleeding index (mSBI), probing depth (PD), and gingival papilla height. Results: The controls group (patients without bone grafting), implantation group, and delayed GBR implantation group followed 58, 76, 26 implants in 26, 32, 13 patients aging at (46.5±9.9), (45.5±10.7), (58.3±6.4) respectively. The duration of the follow-up was (11.2±0.7), (11.1±0.8), (11.1±0.9) years respectively. The 10-year implant survival rate was 100% (58/58), 100% (76/76), 100% (26/26). The MBL was (0.91±0.28), (0.84±0.27), (1.01±0.27) mm respectively. The MBL difference of patients with simultaneous GBR implantation and delayed GBR implantation showed statistical significance (P<0.05), but these two groups showed no statistical significance compared with the controls group (P>0.05). The mPI, mSBI, PD, and gingival papilla height of the three groups all had no significance on statistics (P>0.05). Conclusions: It can be concluded that there is no difference in long-term marginal bone resorption between simultaneous and delayed implantation with or without GBR (using autologous blood mixed with granular bone meal) in the posterior mandibular area.

Reduced miR-363-3p expression in non-small cell lung cancer is associated with gemcitabine resistance via targeting of CUL4A

The article "Reduced miR-363-3p expression in non-small cell lung cancer is associated with gemcitabine resistance via targeting of CUL4A", W.-G. Bian, X.-N. Zhou, S. Song, H.-T. Chen, Y. Shen, P. Chen, published in Eur Rev Med Pharmacol Sci 2019; 23 (2): 649-659-DOI: 10.26355/eurrev_201901_16879-PMID: 30720173, has been retracted by the authors due to several inaccuracies in the research design. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/16879.

Exclusive breastfeeding in rural Western China: does father's co-residence matter?

BACKGROUND

China suffers from a low exclusive breastfeeding rate. Though it has been proofed that paternal support benefits breastfeeding a lot, the correlation between father's co-residence and exclusive breastfeeding in China remain undiscovered. This study is to provide population-based evidence for the association of paternal co-residence on exclusive breastfeeding in rural western China. We also attempt to detect how the process works by examining the correlation between the father's co-residence and breastfeeding family support as well as maternal decision-making power.

METHODS

A cross-sectional study was conducted in 13 nationally-designated poverty-stricken counties in the Qinba Mountains area in 2019. Data on breastfeeding practices, the status of fathers co-residence, breastfeeding family support, and maternal decision-making power were collected via structured questionnaires from 452 caregivers-infant pairs. Multivariate regressions were conducted to explore the correlation between paternal co-residence and exclusive breastfeeding.

RESULTS

The exclusive breastfeeding (0-6 months) rate was 16% in rural western China. Fathers' co-residence was associated with a lower exclusive breastfeeding rate (OR = 0.413, 95% CI = 0.227-0.750, P = 0.004) and the rate did not improve when the father was the secondary caregiver. Even ruling out support from grandmothers, the association was still negative. Paternal co-residence did not improve maternal perceived breastfeeding family support, neither practically nor emotionally (β =0.109, P = 0.105; β =0.011,P = 0.791, respectively) and it reduced maternal decision-making power (β = - 0.196, P = 0.007).

CONCLUSIONS

Fathers' co-residence is negatively associated with the exclusive breastfeeding rates in rural western China. More skill-based practical and emotional strategies should be considered on father's education to help them better involvement and show more respect to mothers' decisions.

Potent SARS-CoV-2 neutralizing antibodies with protective efficacy against newly emerged mutational variants

Accumulating mutations in the SARS-CoV-2 Spike (S) protein can increase the possibility of immune escape, challenging the present COVID-19 prophylaxis and clinical interventions. Here, 3 receptor binding domain (RBD) specific monoclonal antibodies (mAbs), 58G6, 510A5 and 13G9, with high neutralizing potency blocking authentic SARS-CoV-2 virus display remarkable efficacy against authentic B.1.351 virus. Surprisingly, structural analysis has revealed that 58G6 and 13G9 both recognize the steric region S^470–495 on the RBD, overlapping the E484K mutation presented in B.1.351. Also, 58G6 directly binds to another region S^450–458 in the RBD. Significantly, 58G6 and 510A5 both demonstrate prophylactic efficacy against authentic SARS-CoV-2 and B.1.351 viruses in the transgenic mice expressing human ACE2 (hACE2), protecting weight loss and reducing virus loads. Together, we have evidenced 2 potent neutralizing Abs with unique mechanism targeting authentic SARS-CoV-2 mutants, which can be promising candidates to fulfill the urgent needs for the prolonged COVID-19 pandemic.

Neutralizing antibodies are currently one versatile strategy to treat SARS-CoV-2 infection. Here, Li et al. characterize three monoclonal antibodies neutralizing authentic virus infection in vitro and in vivo by targeting the receptor binding domain as evidenced by Cryo-EM.