The preventive effect and mechanism of Dayuanyin in hypoxic pulmonary hypertension through NF-kappaB signaling pathway.

Dayuanyin (DYY) has been shown to reduce lung inflammation in both coronavirus disease 2019 (COVID-19) and lung injury. This experiment was designed to investigate the efficacy and mechanism of action of DYY against hypoxic pulmonary hypertension (HPH) and to evaluate the effect of DYY on the protection of lung function. Animal welfare and experimental procedures are approved and in accordance with the provision of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Science. Male C57/BL6J mice were randomly divided into 4 groups: control group, model group, DYY group (800 mg.kg-1), and positive control sildenafil group (100 mg.kg-1). The animals were given control solvents or drugs by gavage three days in advance. On day 4, the animals in the model group, DYY group and sildenafil group were kept in a hypoxic chamber containing 10% +/- 0.5% oxygen, and the animals in the control group were kept in a normal environment, and the control solvent or drugs continued to be given continuously for 14 days. The right ventricular systolic pressure, right ventricular hypertrophy index, organ indices and other metrics were measured in the experimental endpoints. Meantime, the expression levels of the inflammatory factors in mice lung tissues were measured. The potential therapeutic targets of DYY on pulmonary hypertension were predicted using network pharmacology, the expression of nuclear factor kappa B (NF- kappaB) signaling pathway-related proteins were measured by Western blot assay. It was found that DYY significantly reduced the right ventricular systolic pressure, attenuated lung injury and decreased the expression of inflammatory factors in mice. It can also inhibit hypoxia-induced activation of NF- kappaB signaling pathway. DYY has a protective effect on lung function, as demonstrated by DYY has good efficacy in HPH, and preventive administration can slow down the disease progression, and its mechanism may be related to inhibit the activation of NF-kappaB and signal transducer and activator of transcription 3 (STAT3) by DYY.Copyright © 2023, Chinese Pharmaceutical Association. All rights reserved.

Increases in expression of carbohydrate sulfotransferases CHST11 and CHST15 and decline in N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB) require phospho-p38-MAPK following exposure to SARS-CoV-2 spike protein receptor binding domain in human a

Objective: Immunohistochemistry of post-mortem lung tissue from Covid-19 patients with diffuse alveolar damage demonstrated marked increases in chondroitin sulfate and CHST15 and decline in N-acetylgalactosamine-4-sulfatase. Studies were undertaken to identify the mechanisms involved in these effects. Method(s): Human primary small airway epithelial cells (PCS 301-010;ATCC) were cultured and exposed to the SARSCoV- 2 spike protein receptor binding domain (SPRBD;AA: Lys310-Leu560;Amsbio). Expression of the spike protein receptor, angiotensin converting enzyme 2 (ACE2), was enhanced by treatment with Interferon-beta. Promoter activation, DNA-binding, RNA silencing, QPCR, Western blots, ELISAs, and specific enzyme inhibitors were used to elucidate the underlying molecular mechanisms. Result(s): Treatment of the cultured cells by the SPRBD led to increased CHST15 and CHST11 expression and decline in ARSB expression. Sulfotransferase activity, total chondroitin sulfate, and sulfated glycosaminoglycan (GAG) content were increased. Phospho-T180/T182-p38-MAPK and phospho- S423/S425-Smad3 were required for the activation of the CHST15 and CHST11 promoters. Inhibition by SB203580, a phospho-p38 MAPK inhibitor, and by SIS3, a Smad3 inhibitor, blocked the CHST15 and CHST11 promoter activation. SB203580 reversed the SPRBD-induced decline in ARSB expression, but SIS3 had no effect on ARSB expression or promoter activation. Phospho-p38 MAPK was shown to reduce retinoblastoma protein (RB) S807/S811 phosphorylation and increase RB S249/T252 phosphorylation. E2F-DNA binding declined following exposure to SPRBD, and SB203580 reversed this effect. This indicates a mechanism by which SPRBD, phospho-p38 MAPK, E2F, and RB can regulate ARSB expression and thereby impact on chondroitin 4-sulfate and dermatan sulfate and molecules that bind to these sulfated GAGs, including Interleukin-8, bone morphogenetic protein-4, galectin-3 and SHP-2 (Src homology region 2-containing protein tyrosine phosphatase 2). Conclusion(s): The enzyme ARSB is required for the degradation of chondroitin 4-sulfate and dermatan sulfate, and accumulation of these sulfated GAGs can contribute to lung pathophysiology, as evident in Covid-19. Some effects of the SPRBD may be attributable to unopposed Angiotensin II, when Ang1-7 counter effects are diminished due to binding of ACE2 with the SARS-CoV-2 spike protein and reduced production of Ang1-7. Aberrant cell signaling and activation of the phospho-p38 MAPK and Smad3 pathways increase CHST15 and CHST11 production, which can contribute to increased chondroitin sulfate in infected cells. Decline in ARSB may occur as a consequence of effects of phospho-p38 MAPK on RB phosphorylation and E2F1 availability. Decline in ARSB and the resulting impaired degradation of sulfated GAGs have profound consequences on cellular metabolic, signaling, and transcriptional events. Funding is VA Merit Award.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Integrated Lactate Is Improved with a Novel Pharmacologic Inducer of the Endogenous Cytoprotective Heat Shock Protein 70I Gga and Potential COVID Applications

Introduction: Lactate is a common biomarker used in multiple surgical subspecialties. No one has previously measured coronary sinus lactate reduction as a result of drug administration. We therefore tested the hypothesis that IV geranylgeranylacetone (GGA), a novel agent used to treat human peptic ulcer disease, would result in reduced coronary sinus lactate production. Method(s): New Zealand adult rabbits (N=5 each) received IV 50 mg/kg GGA 24 hours before intervention, which consisted of Langendorff perfusion, 30 min of global normothermic cardioplegic arrest, followed by reperfusion. Myocardial release of lactate was measured. HSP70 was quantified by western blot. Differences between GGA+ and GGA- groups pre- and post-ischemia were analyzed by unpaired t-tests. Result(s): In the GGA- group, lactate increased immediately at one minute and throughout the duration of reperfusion. However, in GGA+ hearts, lactate also increased at one min of reperfusion but then continued to decrease throughout the remainder of reperfusion. Lactate was significantly less at every time point of reperfusion in GGA+. Integrated lactate area was significantly less throughout reperfusion in GGA+. Conclusion(s): GGA induced caused a marked decrease in coronary sinus lactate release during reperfusion. Simultaneously intravenously GGA induced myocardial HSP70i and reduced myocardial damage. Further study of the effects and mechanisms involved is indicated. Application to other organs is useful as well. Heat shock proteins (HSPS) are also antithrombotic. Given the thrombotic nature of Covid, induction of HSPS may be beneficial in decreasing the cardiac thoracic and vascular complications of Covid and allowing faster resolution of this disease during to vascular complications.

SARS-CoV-2 infection disrupts trophoblast function and placental syncytial barrier integrity via its accessory protein, ORF3a

Problem: Although it is rare for a SARS-CoV-2 infection to transmit vertically to the fetus during pregnancy, there is a significantly increased risk of adverse pregnancy outcomes due to maternalCOVID- 19. However, there is a poor understanding of such risks because mechanistic studies on how SARS-CoV-2 infection disrupts placental homeostasis are significantly lacking. The SARS-CoV-2 proteome includes multiple structural and non-structural proteins, including the non-structural accessory proteinORF3a. The roles of these proteins in mediating placental infection remain undefined. We and others have shown that autophagy activity in placental syncytium is essential for barrier function and integrity. Here, we have used clinical samples and cultured trophoblast cells to evaluate syncytial integrity of placenta exposed to SARS-CoV-2. The objective of our study was to investigate potential mechanisms through which SARS-CoV-2 impairs placental homeostasis and causes adverse pregnancy outcomes. We tested the central hypothesis that an essential SARS-CoV-2 non-structural and accessory protein, ORF3a, uniquely (amongst multiple viral proteins tested) with a novel three-dimensional structure andwith no homology to any other proteins is a key modulator of placental trophoblast cell dynamics via autophagy and intracellular trafficking of a tight junction protein (TJP), ZO-1. Method(s): We used clinical samples and cultured trophoblast cells to evaluate syncytial integrity of placentas exposed to SARS-CoV- 2. Autophagic flux was measured in placental villous biopsies from SARS-CoV-2-exposed and unexposed pregnant women by quantifying the expression of autophagy markers, LC3 and P62. Trophoblast cells (JEG-3, Forskolin-treated JEG-3, HTR8/SVneo, or primary human trophoblasts (PHTs)) were transfected with expression plasmids encoding SARS-CoV-2 proteins including ORF3a. Using western blotting, multi-label immunofluorescence, and confocal imaging, we analyzed the effect of ORF3a on the autophagy, differentiation, invasion, and intracellular trafficking of ZO-1 in trophoblasts. Using coimmunoprecipitation assays, we tested ORF3a interactions with host proteins. t-tests and one-way analyses of variance (ANOVAs) with post hoc tests were used to assess the data, with significance set at P < .05. Result(s): We discovered :1) increased activation of autophagy, but incomplete processing of autophagosome-lysosomal degradation;2) accumulation of protein aggregates in placentas exposed to SARS-CoV- 2. Mechanistically, we showed that the SARS-CoV-2 ORF3a protein, uniquely 3) blocks the autophagy-lysosomal degradation process;4) inhibits maturation of cytotrophoblasts into syncytiotrophoblasts (STBs);5) reduces production ofHCG-beta, a key pregnancy hormone that is also essential for STB maturation;and 6) inhibits trophoblast invasive capacity. Furthermore, ORF3a harbors an intrinsically disordered C-terminus withPDZ-bindingmotifs.We show for the first time that, 7) ORF3a binds to and co-localizes with the PDZ domain of ZO-1, a junctional protein that is essential for STB maturation and the integrity of the placental barrier. Conclusion(s): Our work outlines a new molecular and cellular mechanism involving the SARS-CoV-2 accessory protein ORF3a that may drive the virus's ability to infect the placenta and damage placental syncytial integrity. This implies that the mechanisms facilitating viral maturation, such as the interaction of ORF3a with host factors, can be investigated for additional functionality and even targeted for developing new intervention strategies for treatment or prevention of SARS-CoV-2 infection at the maternal-fetal interface.

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies.

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

Coronavirus murine hepatitis virus strain 3 induces intestinal injury via caspase 3 dependent apoptosis

Background: Diarrhea was typical symptoms of the coronavirus disease 2019 (COVID-19). However, the underlying mechanism had not been fully understood. Aim(s): The study aimed to explore the mechanism of intestinal injury during COVID-19 in a coronavirus murine hepatitis virus strain 3 (MHV-3) induced acute mouse model. Method(s): MHV-3 induced acute infection Balb/cJ mice model was established. Intestine samples were collected at indicated time points as 0 h, 24 h, 48 h and 60 h post infection. The mRNA and protein expression of IL1b, TNFalpha, IL6, caspase 3 and cleaved caspase 3 were examined by real-time quantitative PCR (qPCR) and western blot respectively. The intestine injury and apoptosis were measured by HE staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Moreover, Z-DEVD-FMK (caspase 3 inhibitor) pre-treated MHV-3 infection mice model were established, in which the apoptosis of intestine was evaluated as well. Meanwhile, the murine intestinal cell MODE-K was infected by MHV-3 in vitro for evaluation of virus induced apoptosis. Result(s): Post MHV-3 infection, the histopathology of intestine tissue showed extraordinary injury with time dependence, as well as high level of TUNEL positivity. The mRNA levels of inflammatory cytokine IL1b, TNFalpha and IL6 were significantly increased. The protein expressions of caspase 3 and cleaved caspase 3 in the intestine was found significantly elevated from 24 to 48 h post MHV-3 infection. Z-DEVD-FMK pretreatment inhibited caspase 3 and cleaved caspase 3 expression and decreased TUNEL positivity. Meanwhile, alleviated gut injury and inhibited TNFalpha expression were observed. In vitro treated by MHV-3, intestinal cell line MODE-K showed nine-fold increase of apoptosis by comparison with saline treated ones. The expressions of apoptosis crucial protein caspase3 and cleaved caspase3 significantly elevated, as well as TNFalpha. Conclusion(s): Coronavirus murine hepatitis virus strain 3 induces intestinal injury via caspase 3 dependent apoptosis, which might shed light on the treatment of intestinal complications in COVID-19.

Glycyrrhizin inhibits swine acute diarrhea syndrome coronavirus infection via the HMGB1/TLR4/JNK signal pathway

Swine acute diarrhea syndrome coronavirus (SADS-CoV), a newly discovered enteric coronavirus, is the etiological agent that causes severe clinical diarrhea and intestinal pathological damage in piglets. In this study, Vero E6 and IPI-2I cells were pretreated with different concentrations of glycyrrhizin (GLY) for 2 hours, and then infected with different concentrations of SADSCoV, aiming to investigate the inhibitory effect of GLY on SADS-CoV. Western blot and TCID50 results revealed a significantly decreased N protein expression and viral titer, indicating that GLY can inhibit the infection of SADS-CoV. Vero E6 and IPI-2I cells were pretreated with different concentrations of GLY for 2 hours and infected with SADS-CoV. Western blot results showed that when the concentration of GLY was 0.8 mmol/L, the expression of N protein decreased significantly, indicating that GLY inhibited the invasion of the virus. At first, cells were treated with 0.4 mmol/L GLY, and cell samples were collected at 2 hours, 6 hours and 12 hours after being infected with SADS-CoV for analysis, and the expression of N protein were found to be significantly reduced at all points, indicating that GLY had a significant inhibitory effect on the replication of the virus. GLY is a competitive inhibitor of high mobility group box 1 (HMGB1), and the receptors of HMGB1 mainly include TLR4 and RAGE. Based on this fact, the mutant plasmid at the key sites of HMGB1 (C45S, C106S, C45/106S) and the siRNA of the RAGE receptor were transfected to Vero E6 cells and infected with SADS-CoV, and the cell supernatant and samples were harvested. The western blot and TCID50 results showed that the expression of N protein and the virus titer were decreased, suggesting that GLY exerts its function by affecting the binding of HMGB1/TLR4/RAGE during SADS-CoV infection. To further explore the signaling pathway through which GLY functions, Vero E6 and IPI-2I cells were inoculated with SADS-CoV, and cell samples were harvested, western blot was used to detect the changes of MAPK proteins. The results showed that the protein expression levels of p-p38, p-JNK and p-ERK were up-regulated in the early and late stages, indicating that the MAPK pathway was activated by SADS-CoV infection. Vero E6 and IPI-2I were pretreated with different concentrations of GLY and TLR4 inhibitor TAK for 2 hours and infected with SADS-CoV. Protein samples were harvested and analysed by western blot which showed a decreased p-JNK and N proteins, while other proteins showed no significant changes. These results indicated that GLY and TAK regulated the phosphorylation of JNK but did not regulate the phosphorylation of p38 and ERK. Also, Vero E6 cells were treated with HMGB1 antibody, the siRNA of HMGB1 and HMGB1 mutants plasmid, and infected with SADS-CoV. Protein samples were harvested, western blot results showed that phosphorylation of JNK decreased, indicating that HMGB1 affected JNK phosphorylation. Finally, Vero E6 and IPI-2I cells were pretreated with different concentrations of JNK inhibitor SP600125 to infect SADS-CoV, western blot, TCID50 and IFA results showed that the expression of N protein and virus titer, as well as virus replication were reduced, indicating that SP600125 inhibited virus replication. In conclusion, our results revealed that GLY can inhibit in vitro replication of SADS- CoV, mainly through the HMGB1/TLR4/JNK signaling pathway. The discovery of this pathway provides theoretical support for the research of novel anti-SADS-CoV drugs.

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

THE SPIKE OF SARS-CoV-2 VARIANTS ALLOWS FOR MORE EFFICIENT COUNTERACTION OF BST2

Background: BST2/Tetherin is an interferon-stimulated gene with antiviral activity against enveloped viruses. Particularly, BST2 tethers virions at their site of assembly, preventing their release and spread. In addition to this primary role, BST2 is as an important bridge between the innate and adaptive immune system, since (i) BST2 routes tethered particles to lysosomes, which generates viral breakdown products that engage pattern recognition receptors;and (ii) trapped virions facilitate antibody-dependent cell-mediated cytotoxicity (ADCC). In turn, viruses have evolved mechanisms to bypass BST2, either by targeting BST2 for proteasomal/lysosomal degradation or by removing BST2 from sites of virion assembly. However, the role of BST2 in SARS-CoV-2 replication, spread, evolution, and pathogenesis remains largely unknown. Method(s): The antiviral potential of BST2 against SARS-CoV-2 was investigated by infecting different SARS-CoV-2 isolates (Hong Kong, Alpha, Beta, Delta, and Omicron) in BST2+ and BST2- cells. Culture supernatants were collected to assess virion production by ELISA and infectivity by TCID50. Infected cells were analyzed by western blot and flow cytometry to examine viral and cellular protein levels, including BST2. Transfection of individual SARS-CoV-2 ORFs and mutagenesis studies allowed us to identify the genes that the virus uses to downregulate BST2. Immunoprecipitation assays revealed protein-protein interactions and changes in ubiquitination patterns. Experiments with proteasomal and lysosomal inhibitors furthered our mechanistic understanding of how SARS-CoV-2 counteracts BST2. Finally, fluorescence microscopy studies uncovered changes in the subcellular distribution of BST2 in SARS-CoV-2 infected cells. Result(s): While BST2 reduces virion release, SARS-CoV-2 has evolved to counteract this effect. Specifically, SARS-CoV-2 uses the Spike to interact with BST2, sequester the protein at perinuclear locations, and ultimately route it for lysosomal degradation. By surveying different SARS-CoV-2 variants of concern (Alpha-Omicron), we found that each variant is more efficient than the previously circulating strain at downregulating BST2 and facilitating virion production, and that mutations in the Spike account for their enhanced BST2 antagonism. Conclusion(s): As part of its adaptation to humans, SARS-CoV-2 is improving its capacity to counteract BST2, highlighting that BST2 antagonism is important for SARS-CoV-2 infectivity and transmission.

cGAS-STING PATHWAY LIMITS SARS-CoV-2 REPLICATION IN ACE2+ AIRWAY CELL LINES

Background: We previously screened 10 human lung and upper airway cell lines expressing variable levels of endogenous ACE2/TMPRSS2. We found that H522 human lung adenocarcinoma cells supported SARS-CoV-2 replication independent of ACE2, whereas the ACE2 positive cell lines were not permissive to infection. Type I/III interferons (IFNs) potently restrict SARS-CoV-2 replication through the actions of hundreds of interferon-stimulated genes (ISGs) that are upregulated upon IFN signaling. Here we report that a number of ACE2 positive airway cell lines are unable to support SARS-CoV-2 replication due to basal activation of the cGAS-STING DNA sensing pathway and subsequent upregulation of IFNs and ISGs which restrict SARS-CoV-2 replication. Method(s): SARS-CoV-2 WT strain 2019-nCoV/USA-WA1/2020 viral replication was detected through analysis of cell associated RNA. RNA sequencing was used to study the basal level of genes in the type-I IFN pathway in the 10 cell lines, which was further validated by western blotting and qRT-PCR. A panel of 5 cell lines, with varying expression levels of ACE2 and TMPRSS2, were pre-treated with Ruxolitinib, a JAK1/2 inhibitor. A siRNA-mediated screen was used to determine the molecular basis of basally high expression of ISGs in cell lines. CRISPR knockout of IFN-alpha receptor and cGAS-STING pathway components was conducted in parallel Results: Here we show that higher basal levels of IFN pathway activity underlie the inability of ACE2+ cell lines to support virus replication. Importantly, this IFN-induced block can be overcome by chemical inhibition and genetic disruption of the IFN signaling pathway or by ACE2 overexpression, suggesting that one or more saturable ISGs underlie the lack of permissivity of these cells. Ruxolitinib treatment increased SARS-CoV-2 RNA levels by nearly 3 logs in OE21 and SCC25. Furthermore, the baseline activation of the STING-cGAS pathway accounts for the high ISG levels and genetic disruption of the cGAS-STING pathway enhances levels by nearly 2 and 3 logs of virus replication in the two separate ACE2+ cell line models respectively. Conclusion(s): Our findings demonstrate that cGAS-STING-dependent activation of IFN-mediated innate immunity underlies the inability of ACE2+ airway cell lines to support SARS-CoV-2 replication. Our study highlights that in addition to ACE2, basal activation of cGAS-STING pathway, IFNs and ISGs may play a key role in defining SARS-CoV-2 cellular tropism and may explain the complex SARS-CoV- 2 pathogenesis in vivo.

A New CURE in Molecular Biology: Testing a Novel Pyrrolidine Compound to Determine Mechanism of Action in an Upper-Division Molecular Biology Course

The COVID-19 pandemic shut down forced introductory biology and chemistry laboratory courses online at DePauw University from March 2020-June 2021, leaving multiple classes of students without the opportunity to learn basic laboratory skills that are essential for the molecular biology laboratory. In an effort to provide students with both basic laboratory skills and advanced molecular biology skills, a new course-based undergraduate research experience (CURE) was developed for the 2022-23 academic year. In collaboration with Dr. Jeff Hansen in the Chemistry and Biochemistry department, novel compounds with potential anti-tumor properties were identified. The CURE in Molecular Biology was designed to have students use Saccharomyces cerevisiae as a model system to evaluate possible cellular pathways affected by the compound, including: cytoskeleton and cell migration, nucleotide biosynthesis, glucose metabolism, apoptosis, and cell cycle regulation. Students learned techniques DNA isolation and PCR, transformation, RNA isolation, cDNA synthesis, qPCR, and Western Blotting, while contributing to an active research project. At the conclusion of the project, students were surveyed about their comfort with molecular techniques and data analysis.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Preparation and identification of broad-spectrum monoclonal antibodies against N protein of avian infectious bronchitis virus

[Objective] To prepare broad-spectrum monoclonal antibody against N protein of avian infectious bronchitis virus (IBV), so as to lay a foundation for identifying conservative domain epitope of N protein and establish a universal IBV detection method. [Method] N protein of GX-YL5, a representative strain of IBV dominant serotype in Guangxi, was expressed in prokaryote. BALB/c mice were immunized with the purified protein. After the serum titer of the immunized mice reached 104 or more, the splenocytes were fused with SP2/0 myeloma cells. After screening by indirect ELISA, monoclonal antibody was prepared by ascites-induced method. Western blotting, IFA and indirect ELISA were used to identify the titer, subtype, reaction specificity and cross-reaction spectrum. And the prepared monoclonal antibody was used for immunohistochemical detection. And the prepared monoclonal antibody was used to detect the IBV in the trachea and kidney tissues of SPF chickens artificially infected with 4 representative IBV variants (GX-N130048, GX-N160421, GX-QZ171023 and GX-QZ170728). [Result] The prepared monoclonal antibody N2D5 had a titer greater than 217 and its subtype was IgG2b. The Western blotting and IFA results showed that the monoclonal antibody N2D5 only reacted with IBV, and were negative with Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV), infectious bursal disease virus (IBDV), avian leukosis virus (ALV) and Marek's disease virus (MDV). Monoclonal antibody N2D5 reacted with many genotypes in China and all 7 serotypes of IBV currently prevalent in Guangxi, including commonly used standard strains, vaccine strains and field strains. Immunohistochemistry showed that the virus signals could be detected in the trachea and kidney tissues of SPF chickens at different time after artificial infection of 3 representative IBV strains from chicken and 1 isolated strain from duck, which further proved its broad spectrum. [Conclusion] The monoclonal antibody N2D5 of IBV prepared based on hybridoma technology belongs to the IgG2b subtype. It has the characteristics of high specificity, wide response spectrum and strong binding ability with IBV. It can be used as a specific diagnostic antibody for clinical diagnosis of IBV and the study of virus distribution.

LONG NON-CODING RNA REGULATES IFN-I RESPONSE AND SARS-CoV-2 REPLICATION

Background: Infection with SARS-CoV-2 triggers reprogramming through global transcriptomic changes that drive the development of Coronavirus disease 2019 (COVID-19). Although the expression and functions of proteincoding transcripts have been widely studied in SARS-CoV-2 infection, most of the transcriptome consists of non-protein-coding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs), which constitute a large proportion of the transcriptome, regulate immune responses and play prominent roles in health and disease. However, the impact of lncRNAs on SARS-CoV-2 infection is poorly understood. Our study will provide fundamental insights into the role of lncRNAs in SARS-CoV-2 infection. Method(s): We hypothesized that SARS-CoV-2-induced lncRNAs are critical regulators of viral replication and immune response. To test our hypothesis, we identified lncRNAs with significant differential expression in SARS-CoV-2 infected vs. uninfected cells across two cell types (A549-hACE2 and Calu) from published transcriptome data. We silenced the expression of the top lncRNA Bre- AS1 (BA) a human lung epithelial cell model (A549 cells stably expressing hACE2 and hTMPRSS2, A549AT) using lncRNA-specific ASO (lncsi) or negative control (NC) and compared viral replication in lncsi vs. NC cells. BA-silencing (BA-si) increased SARS-CoV-2 replication. and inhibited the expression of antiviral interferon-stimulated genes (ISG). (Tyr 705) pSTAT3 forms suppressor molecular complexes (pSTAT3-pSTAT1 or pSTAT3-PLSCR2) that inhibit ISG transcription. Using molecular methods such as gene-silencing, immunoprecipitation, western blot, and measuring promoter activity, we further show that Bre-AS1 inhibits the phosphorylation of STAT3 and enhances ISG transcription. Result(s): Our data show that cellular lncRNA, Bre-AS1 enhances antiviral interferon-stimulated genes (ISG) expression and inhibits replication of SARSCoV- 2. Our data show that Bre-AS1 inhibits the (Tyr705) phosphorylation of STAT3 that forms ISG repressor complexes (pSTAT3-pSTAT1 or pSTAT3-PLSCR2) and thus enhances ISG transcription. Conclusion(s): Cellular lncRNA Bre-AS1 enhances expression of antiviral interferon-stimulated genes and inhibits the replication of SARS-CoV-2. Our data show that cellular lncRNAs could play significant roles in immune response and viral propagation. Thus, unraveling the mechanisms of lncRNA-mediated regulation of virus replication and immune response may lead to identifying new, highly selective therapeutic targets Bre-AS1 inhibits STAT3 phosphorylation and enhances ISG transcription.

Extracellular vesicles as delivery vectors to enhance killing of bacteria and viruses by airway-recruited human neutrophils

Background: Polymorphonuclear neutrophils (PMNs) recruited to the airway lumen in cystic fibrosis (CF) undergo a rapid transcriptional program, resulting in exocytosis of granules and inhibition of bacterial killing. As a result, chronic infection, feed-forward inflammation, and structural tissue damage occur. Because CF airway PMNs are also highly pinocytic, we hypothesized that we could deliver protein- and ribonucleic acid (RNA)-based therapies to modulate their function to benefit patients. We elected to use extracellular vesicles (EVs) as a delivery vector because they are highly customizable, and airway PMNs have previously been shown by our group to process and use their cargo efficiently [1]. Furthermore, our prior work on CF airway PMNs [2] led to identification of the long noncoding RNA MALAT1, the transcription factor Ehf, and the histone deacetylase/long-chain fatty deacylase HDAC11 as potential targets to modulate CF airway PMN dysfunction. Method(s): H441 human club epithelial cells were chosen for EV production because they efficiently communicate with lung-recruited primary human PMNs [1]. Relevant constructs were cloned into an expression plasmid downstream of a constitutive cytomegalovirus or U6 promoter with an additional puromycin selection cassette. EVs were generated in serumdepleted media and purified by differential centrifugation. Quality and concentration of EVs was determined by electron microscopy and nanoparticle tracking analysis and cargo content by western blot (protein) or qualitative reverse transcription polymerase chain reaction (RNA). Enhanced green fluorescent protein and messenger ribonucleic acid (mRNA) were used as controls. To test delivery to primary human PMNs, generated EVs were applied in the apical fluid of an airway transmigration model [2]. PMN activation was assessed by flow cytometry, and bacterial (PA01 and Staphylococcus aureus 8325-4) killing and viral (influenza Avirus [IAV] H1N1/PR/8/34;SARS-CoV-2/Washington) clearance assays were conducted. Result(s): To package protein, we used EV-loading motifs such as the tetraspanin CD63, Basp1 amino acids 1-9, and the palmitoylation signal of Lyn kinase. To load mRNA, a C'D box motif recognized by the RNA-binding protein L7Ae was included in the 3' untranslated region of the expressed RNA, and CD63-L7Ae was co-expressed. Airway-recruited PMNs treated with EVs containing small interfering RNAs against MALAT1 or HDAC11 showed greater ability to clear bacteria. Conversely, PMNs treated with constructs encasing MALAT1 or HDAC11 efficiently cleared IAV and SARSCoV- 2. PMNs expressing Ehf showed greater clearance of bacteria and viruses. Conclusion(s): Our findings suggest mutually exclusive roles of MALAT-1 and HDAC11 in regulating bacterial and viral clearance by airway-recruited PMNs. Expression of Ehf in airway PMNs may be a pathogen-agnostic approach to enhancing clearance by airway-recruited PMNs. Overall, our study brings proof-of-concept data for therapeutic RNA/protein transfer to airway-recruited PMNs in CF and other lung diseases and for use of EVs as a promising method for cargo delivery to these cells. It is our expectation that, by treating the immune compartment of CF airway disease, pathogentherapies, such as antibiotics will be more effective, and epithelial-targeted therapies, such as CFTR modulators, will have greater penetrance into the cell types of interest.Copyright © 2022, European Cystic Fibrosis Society. All rights reserved

Production and characterisation of a SARSCoV-2 S-protein RBD homodimer with increased avidity for specific antibodies.

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

Evaluation of expression and titration of recombinant nucleocapsid protein as an immunogenic candidate against SARS-CoV2.

Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate Material(s) and Method(s): B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Result(s): The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high-frequency distribution was improved to 85%. Expression of recombinant protein in E.coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000 Conclusion(s): According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.Copyright © 2022, Semnan University of Medical Sciences. All rights reserved.

Immunogenicity, safety and efficacy in the CVID patients -Data from the 6-month prospective study

Background: A single-stranded mRNA virus SARS-CoV- 2 is associated with severe acute respiratory syndrome in the predisposed individuals such as elderly, obese, chronic cardiovascular or pulmonary diseases. Higher risk for severe course was also reported in inborn errors of immunity (IEI). While restriction measures play important role from the short-term perspective, vaccination may provide long-term protection. However, only limited data are available on safety and efficacy in immunocompromised patients with IEI such as Common variable immunodeficiency (CVID). Method(s): We assessed humoral and cellular responses, safety and efficacy in a cohort of 20 CVID patients after 2 doses of anti-SARS- CoV- 2 vaccine BNT162b. The humoral reponse was evaluated using ELISA and western blot methods, the T cell response measured by IFNg secretion functional assay. Adverse events were reported by Patient Clinical Questionnaire. Blood count, biochemical, coagulation and immunological parameters were checked before and after vaccination. The patients were followed for 6 months. Result(s): Despite severely impaired antibody production hunoral response was detected in 48% (n = 10/21) of patients at month 1. However, the response persisted in only 33% (n = 6/18) at month 3 and further decreaed to 13% (n = 2/15) at month 6. The T cell response was measurable in 5 patients (28%) at month 1. In total, 4 out of 20 (20%) patients got infected within the study period. None of them required oxygenotherapy or hospital admission. We did not observe any severe adverse effects beyond local pain, fatigue, headche, fever, arthralgia and myalgia. Conclusion(s): Vaccination with mRNA vaccine BNT162b provides safe and effective protection for a subgroup of CVID patients. However, the immunogenicity is lower compared to the general population.

Construction and immunogenicity of recombinant rabies virus expressing S gene of SARS-CoV-2

[Background] The coronavirus disease 2019（COVID-19） pandemic has lasted for nearly three years in the globe, which has not only caused serious harm to humans but also affected companion animals. The COVID-19 vaccines for human have been used globally, while those for animals are rarely reported. [Objective] To develop a bivalent vaccine against both severe acute respiratory syndrome coronavirus 2（SARS-CoV-2） and rabies virus（RABV） for animal use. [Methods] We cloned the S and S1 genes of SARS-CoV-2 into the region between G and L genes of the attenuated RABV vaccine strain rHEP-Flury to construct the recombinant plasmids pHEP-nCOV-S and pHEP-nCOV-S1, respectively.The two plasmids were respectively co-transfected into BHK-21 cells with the helper plasmids and finally the recombinant viruses rHEP-nCOV-S and rHEP-nCOV-S1 were rescued. The recombinant viruses were confirmed by RT-PCR and direct fluorescent antibody staining against RABV N protein.Western blotting was employed to detect the expression of S and S1 proteins in the cells infected with the recombinant viruses. The growth curves, pathogenicity, and immunogenicity of recombinant viruses were confirmed in NA cells and mice. [Results] The rescued recombinant viruses rHEP-nCOV-S and rHEP-nCOV-S1 respectively carrying the S and S1 genes of SARS-CoV-2 were confirmed by direct fluorescent antibody assay based on the green fluorescence from the supernatants 7 days post infection.rHEP-nCOV-S1 rather than rHEP-nCOV-S showed stronger proliferation and diffusion abilities than the parental virus rHEP-Flury in NA cells. The specific bands at 72 kDa and 144 kDa in the Western blotting confirmed the efficient expression of S and S1 in the recombinant viruses, respectively. The mice vaccinated with the recombinant viruses did not show significant changes in the body weight compared with those vaccinated with rHEP-Flury, and the recombinant viruses induced the production of neutralizing antibody against RABV in mice. [Conclusion] The production of the recombinant RABV carrying the S/S1 gene of SARS-CoV-2 provides a foundation for the development of the bivalent vaccine against both SARS-CoV-2 and rabies virus for animal use.

Intravesical administration of durvalumab to patients with high risk non muscle invasive bladder cancer after BCG failure. A phase II trial by the Hellenic GU Cancer Group

Introduction & Objectives: Patients with high risk non muscle invasive bladder cancer (NMIBC) who experience BCG failure have limited bladder preserving treatment options as radical cystectomy currently represents the standard therapeutical approach. Systematic immunotherapy (IO) has changed the landscape in advanced bladder cancer and is currently being investigated in NMIBC. Based on the hypothesis that intravesical administration will not be related with severe adverse events, we evaluated the role of intravesically administered durvalumab in NMIBC patients after BCG failure. Material(s) and Method(s): An open label, single-arm, multi-center, phase II clinical trial was conducted. A run-in phase had the objective to determine the maximum tolerated dose (MTD) of durvalumab and to exclude a detrimental effect on disease relapse by this strategy. Durvalumab was administered for a total of 6 instillations per patient at consecutive levels of 500, 750 and 1000 mg. Phase II has as primary end point the 1-year high-grade-relapse-free (HGRF)-rate. Secondary endpoints included toxicity, and high-grade progression-free rat at 1, 3 and 6 months after treatment. Result(s): Thirty patients were enrolled (run in phase: 9, phase II: 21). One patient withdrew consent prior to receiving study treatment, so 29 patients were included in efficacy and toxicity analyses. Mean age was 66.5 years. MTD of durvalumab was set at 1000 mg as no dose related toxicities (DLTs) occurred at any level studied. Three of 9 patients included in the run-in phase (33.3%) were tumor free one month after the last durvalumab instillation, therefore, the null hypothesis was rejected by the futility analysis. Western blot showed that durvalumab remained stable in urine during instillation. One patient died from Covid-19, 3 months after the last durvalumab administration. All patients concluded at least 1 year follow up. One-year HGRF rate was 34.6%. HGRF rates at 1, 3 and 6 months was 73%, 65.3% and 50% respectively. Five patients (17%) experienced a T2 or above disease relapse. Five out of the six patients who received 500mg or 750mg of durvalumab relapsed within 1 year. When efficacy analyses were restricted to patients receiving 1000mg of durvalumab, 1-year HGRF rate was 35%. Interestingly, 2 out of 2 patients with only CIS disease at baseline experienced a tumor complete response, which was durable and was maintained at least for a year. No severe adverse events were noted. The most common adverse event was Grade 1 hematuria. Conclusion(s): Intravesical IO using durvalumab was proved to be feasible with an excellent safety profile. Oncological results seem to be promising and comparable with other bladder preserving strategies in BCG failure with the advantage of a better safety profile. Further study of intravesical IO in high-risk patients with NMIBC after BCG failure is warranted.Copyright © 2023 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Changes in surface activity of lung surfactant and bronchoalveolar cell profile upon COVID-19-related Acute Respiratory Distress Syndrome

A contribution of Lung Surfactant (LS) inactivation to COVID-19-related ARDS (cvARDS) has been argued, but not been clearly demonstrated to date. In the present study, we have characterised the extent of lung neutrophil infiltration along with the surface-active properties and protein composition of LS in bronchoalveolar lavages (BALs) collected from 12 cvARDS patients. A control group of 9 subjects without respiratory diseases was also enrolled. BAL cell sorting was performed by flow cytometry. The adsorption of LS at the air-liquid interface was assessed by Surfactant Adsorption Test (SAT), whereas the level of surfactant hydrophobic proteins was measured by Western Blot analysis. Results were normalised by phosphatidylcholine (PC) total amount. Significant increase in neutrophil [61.3(47.5-84.6)% vs 1.6(0.9-4.9)%, p<0.0001] and decrease in macrophage percentages [13.6(6.1-28.9)% vs 90.8(87.1-92-6)%, p<0.0001] of total BAL cells were detected in cvARDS patients. A lower overtime LS adsorption/accumulation at the air-liquid interface was also observed in those patients compared to the control group from 60min onward [14003(10232-19736) vs 24501(16386-28489) RFU, p=0.0471]. Moreover, cvARDS patients under the acute phase showed the lowest surfactant activity at the end of SAT (12191(11588-20159) RFU, p=0.048). An increase in both SP-B and SP-C/PC was also evident in cvARDS BALs. Here, we report for the first time on the reduction of LS surface-active properties during the acute period and even under the recovery phases of cvARDS. This may confirm how LS inactivation may be involved in both early and late consequences of severe cvARDS.