Differential Induction Research Articles

A Differential Strand-Slot Inductance Model for Improved Compensation of Circulating Currents in the Core Part of Large AC Machines

The Roebel bar conventional design of large AC machines uses the classical strand-slot inductance model (CSSIM). Suitable alternatives are missing as the CSSIM is favored for its inherent simplicity based on the ideally permeable iron core hypothesis. However, saturated armature slots can lead to high variations of the slot inductance, where the CSSIM cannot represent this precisely. An accurate prediction of the strand inductances is crucial when optimizing the transpositions of large Roebel bars to be competitive on efficiency and low measurement tolerances. This fact is crucial in under-roebeling, having less than a 360-degree transposition over the active part. In the end, the goal is to compensate the winding overhang parasitic field with the slot-parasitic field. This paper proposes a differential strand-slot inductance model (DSSIM) based on the concept of differential inductance (DI). It is compatible with a circuital lumped-element model (LEM) that considers the strand topology, geometrical dimensions, saturation level, and small- scale effects. Numerical simulations showcase the performance improvement of the DSSIM against known models. Finally, a 20- strand prototype of a slot model with actual Robel bar strands corresponding to a simplified bar cross-section in a large AC machines slot demonstrates the presented DSSIMs precision.

Mathematical modeling of rheostat-reactor start of wound-rotor induction motors

Introduction. Wound-rotor induction motors are less common compared squirrel-cage induction motors. However, they occupy a significant share among electric drives with difficult starting conditions. Their advantage is obtaining a high starting electromagnetic torque at lower values of starting currents. Problem. Due to the possibility of including different devices in the rotor circuit, it is possible to shape the starting characteristics according to the needs of the technological process. Due to a narrower range of applications of electric drives based on wound-rotor induction motors, they are less investigated. Selection of parameters of starting and regulating devices, included in the rotor circuit, is carried out by simplified methods, which do not satisfy modern requirements to regulated electric drives. Goal. The paper aims to develop mathematical models and methods for calculating the dynamic modes and static characteristics of the wound-rotor induction motor with a reactor in the rotor circuit. Methodology. In the developed algorithms, the mathematical model of the motor is presented by the differential equations made for electric circuits in a system of orthogonal coordinates that allows excluding angular coordinate from equations of electric equilibrium. The elements of the Jacobi matrix of equilibrium equations of motor circuits are eigenvalues, and mutual is the differential inductances of electrical circuits, which are determined based on the magnetization characteristics of the main magnetic flux and leakage fluxes of the rotor and stator circuits. Results. Mathematical models for the study of starting modes of wound rotor induction motor allow to calculate transients and static characteristics and, on their basis, to carry out design synthesis of starting reactors, which provide the law of change of electromagnetic torque during start-up operating conditions. Originality. The mathematical basis of the developed algorithms is the method of solving nonlinear systems of equations by Newton method in combination with the method of continuation by parameter. The developed mathematical models and software made on their basis have high speed that allows to carry out high-reliability calculation of starting modes taking into account saturation of a magnetic circuit of the motor. Practical value. The developed algorithms do not require significant computing resources, have high speed, and can be used both for the design synthesis of start-control devices and control of the electric drive in real time and to predict its course.

The epigenetic modifier HDAC2 and the checkpoint kinase ATM determine the responses of microsatellite instable colorectal cancer cells to 5-fluorouracil

The epigenetic modifier histone deacetylase-2 (HDAC2) is frequently dysregulated in colon cancer cells. Microsatellite instability (MSI), an unfaithful replication of DNA at nucleotide repeats, occurs in about 15% of human colon tumors. MSI promotes a genetic frameshift and consequently a loss of HDAC2 in up to 43% of these tumors. We show that long-term and short-term cultures of colorectal cancers with MSI contain subpopulations of cells lacking HDAC2. These can be isolated as single cell-derived, proliferating populations. Xenografted patient-derived colon cancer tissues with MSI also show variable patterns of HDAC2 expression in mice. HDAC2-positive and HDAC2-negative RKO cells respond similarly to pharmacological inhibitors of the class I HDACs HDAC1/HDAC2/HDAC3. In contrast to this similarity, HDAC2-negative and HDAC2-positive RKO cells undergo differential cell cycle arrest and apoptosis induction in response to the frequently used chemotherapeutic 5-fluorouracil, which becomes incorporated into and damages RNA and DNA. 5-fluorouracil causes an enrichment of HDAC2-negative RKO cells in vitro and in a subset of primary colorectal tumors in mice. 5-fluorouracil induces the phosphorylation of KAP1, a target of the checkpoint kinase ataxia-telangiectasia mutated (ATM), stronger in HDAC2-negative cells than in their HDAC2-positive counterparts. Pharmacological inhibition of ATM sensitizes RKO cells to cytotoxic effects of 5-fluorouracil. These findings demonstrate that HDAC2 and ATM modulate the responses of colorectal cancer cells towards 5-FU.Graphical abstract

The TbD1 Locus Mediates a Hypoxia-Induced Copper Response in Mycobacterium bovis.

The Mycobacterium tuberculosis complex (MTBC) contains the causative agents of tuberculosis (TB) in mammals. The archetypal members of the MTBC, Mycobacterium tuberculosis and Mycobacterium bovis, cause human tuberculosis and bovine tuberculosis, respectively. Although M. tuberculosis and M. bovis share over 99.9% genome identity, they show distinct host adaptation for humans and animals; hence, while the molecular basis of host adaptation is encoded in their genomes, the mechanistic basis of host tropism is still unclear. Exploration of the in vitro phenotypic consequences of known genetic difference between M. bovis and M. tuberculosis offers one route to explore genotype–phenotype links that may play a role in host adaptation. The TbD1 (“Mycobacterium tuberculosis deletion 1 region”) locus encompasses the mmpS6 and mmpL6 genes. TbD1 is absent in M. tuberculosis “modern” lineages (Lineages 2, 3, and 4) but present in “ancestral” M. tuberculosis (Lineages 1 and 7), Mycobacterium africanum lineages (Lineages 5 and 6), newly identified M. tuberculosis lineages (Lineages 8 and 9), and animal adapted strains, such as M. bovis. The function of TbD1 has previously been investigated in M. tuberculosis, where conflicting data has emerged on the role of TbD1 in sensitivity to oxidative stress, while the underlying mechanistic basis of such a phenotype is unclear. In this study, we aimed to shed further light on the role of the TbD1 locus by exploring its function in M. bovis. Toward this, we constructed an M. bovis TbD1 knockout (ΔTbD1) strain and conducted comparative transcriptomics to define global gene expression profiles of M. bovis wild-type (WT) and the ΔTbD1 strains under in vitro culture conditions (rolling and standing cultures). This analysis revealed differential induction of a hypoxia-driven copper response in WT and ΔTbD1 strains. In vitro phenotypic assays demonstrated that the deletion of TbD1 sensitized M. bovis to H2O2 and hypoxia-specific copper toxicity. Our study provides new information on the function of the TbD1 locus in M. bovis and its role in stress responses in the MTBC.

Response to Hypoxia and the Ensuing Dysregulation of Inflammation Impacts Mycobacterium tuberculosis Pathogenicity.

Rationale: Different Mycobacterium tuberculosis (Mtb) strains exhibit variable degrees of virulence in humans and animal models. Differing stress response strategies used by different strains of Mtb could influence virulence. Objectives: We compared the virulence of two strains of Mtb with use in animal model research: CDC1551 and Erdman. Methods: Rhesus macaques, which develop human-like tuberculosis attributes and pathology, were infected with a high dose of either strain via aerosol, and virulence was compared by bacterial burden and pathology. Measurements and Main Results: Infection with Erdman resulted in significantly shorter times to euthanasia and higher bacterial burdens and greater systemic inflammation and lung pathology relative to those infected with CDC1551. Macaques infected with Erdman also exhibited significantly higher early inflammatory myeloid cell influx to the lung, greater macrophage and T cell activity, and higher expression of lung remodeling (extracellular matrix) genes, consistent with greater pathology. Expression of NOTCH4 (neurogenic locus notch homolog 4) signaling, which is induced in response to hypoxia and promotes undifferentiated cellular state, was also higher in Erdman-infected lungs. The granulomas generated by Erdman, and not CDC1551, infection appeared to have larger regions of necrosis, which is strongly associated with hypoxia. To better understand the mechanisms of differential hypoxia induction by these strains, we subjected both to hypoxia invitro. Erdman induced higher concentrations of DosR regulon relative to CDC1551. The DosR regulon is the global regulator of response to hypoxia in Mtb and critical for its persistence in granulomas. Conclusions: Our results show that the response to hypoxia is a critical mediator of virulence determination in Mtb, with potential impacts on bacillary persistence, reactivation, and efficiency of therapeutics.

Measurements of magnetic characteristics of laminated Fe-Si steel filter inductors in grid interface converters

The knowledge of the magnetic characteristic of an inductor is a key factor for the design of filters of power converter systems for electric grid interfaces. The accurate and reliable definition and measurement of the parameters such as the differential inductance, the saturation level and the linearity range is a difficult task, in particular for high current inductors. In this paper a comparison between different methods of measure of the magnetic characteristic of a gapped filtering inductor versus current, in the range from zero magnetization to the saturation, is presented and discussed. It is shown that the different measurement methods provide appreciable differences in the evaluation of the magnetic characteristic of a benchmark inductor. The differences found are also analyzed by suitable numerical simulations.

Transcription pattern of key molecular chaperones in heat shocked caprine cardiac fibroblasts

The present study was attempted to unveil the impact of heat stress on transcription pattern of major heat shock response genes in caprine cardiac fibroblasts. Cardiac tissues (n = 6) were collected and primary cardiac cell culture was done. Cultured cardiac fibroblasts were kept in an atmosphere of 5% CO2 and 95% air at 38.5 °C. Cardiac cells achieved 70-75% confluence after 72 hours of incubation. Heat stress was induced on confluent cardiac fibroblasts at 42 °C for 0 (control), 20, 60, 100 and 200 min. Quantitative RT-PCR for β2m (internal control), HSP60, HSP70, HSP90, and HSP110 was done and their transcription pattern was assessed by Pfaffl method. HSP60, HSP90, and HSP110 transcription did not differ at 20 min, up-regulated (p < 0.05) from 60 to 200 min and registered highest at 200 min of heat exposure. HSP70 transcription was gradually escalated (p < 0.05) time dependently from 20 to 200 min and reached zenith at 200 min of heat exposure. Differential induction in transcription of key molecular chaperones at various durations of heat exposure might reduce cardiac fibroblasts apoptosis and thus could maintain cardiac tissue function during heat stress.

T2-high asthma phenotypes across lifespan.

In adults, personalised asthma treatment targets patients with type 2 (T2)-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children. To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages. In the multicentre clinical All Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults)) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with lipopolysaccharide (LPS) or anti-CD3/CD28. Based on blood eosinophil counts and allergen-specific serum IgE antibodies, patients were categorised into four mutually exclusive phenotypes: "atopy-only", "eosinophils-only", "T2-high" (eosinophilia + atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset, suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood. Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at a younger age.

K-band low phase noise Class-C VCOs using DGS inductor in CMOS technology

This work presents two new structures of inductor to improve the performance of K-band class-C voltage-controlled oscillators (VCOs) in 0.18-μm CMOS technology. Conventional inductor provided by the foundry suffers from a poor-quality (Q-) factor large area and low self-resonance frequency. These problems are solved by introducing defected ground structure using the lower layers. The first DGS inductor is a meander-line finger capacitor under C-shape inductor while the second inductor is three loops with finger DGS. The fabricated inductor has wideband characteristics, and additionally, the Q-factor is increased almost by 84% compared to a single loop inductor without DGS. The measured differential inductance and quality factor of the proposed inductor are 180 pH and 30 at K-band. The proposed inductors are used to design a high-performance class-C VCO at K-band. Furthermore, class-C biasing decreases the current drawn from 2.9 mA to 0.8 mA, so the figure of merit (FoM) is improved by 4 dB compared to conventional VCO. The NMOS class-C VCO achieves a frequency tuning range (FTR) from 25 GHz to 26 GHz and has a FoM of -198dBc/Hz whereas the second class-C VCO has a frequency range from 18.9 GHz to 19.8 GHz and phase noise at 1 MHz offset changes from -111.3 to -114.2dBc/Hz.

Differential induction of trained innate immunity following early-life immunization with aluminum adjuvant results in preferential priming of Th2-biased immune responses

While aluminum adjuvant-based vaccines are commonly administered to neonates, their immune effects specific to early life are not well understood. The immature infant immune system is Th2-biased and dependent on environmental cues to mature towards Th1/Th2 balance. Thus, the induction of strong Th2 immunity with alum vaccines in early life may perturb this balance, leading to predisposition towards development of Th2 immunity to subsequent allergen exposure.

Experimental Assessment of a Magnetic Induction-Based Receiver for Magnetic Communication

This paper presents the topology of a novel approach to magnetic communication using a differential magnetic induction (MI)-based receiver and a differential MI receiving sensor. In this paper, a differential MI sensor based on two ferromagnetic cores is proposed as a receiving sensor, unlike the air coil-type MI sensor in the conventional search coil sensor concept. This differential MI sensor has the advantages of ultra-high sensitivity characteristics of the pT/√Hz level, which can detect weak magnetic fields in magnetic communication; moreover, the sensor is smaller than a conventional air coil MI sensor. The proposed differential MI sensor contributes to improving sensor performance by increasing its signal-to-noise ratio. The design and fabrication of the proposed MI sensor were based on a printed circuit board (PCB). The pickup coil of the PCB-based MI sensor directly wound the pickup coil onto a ferromagnetic core composed of Ni-Zn ferrite material. To analyze the key factors that affected the performance of the receiver, the magnetic field-to-voltage conversion ratio (MVCR) and equivalent magnetic spectral density measurements of the proposed PCB-based MI sensor were performed. Wireless digital communication using quadrature phase shift keying (QPSK), which is less sensitive to noise and has a high data rate, was used to evaluate the proposed MI-based receiver. The transmitted and received waveforms were compared to confirm that the transmitted digital data were accurately received as a result of the final demodulation of the receiver. Additionally, several performance metrics, such as constellation and error vector magnitude, were measured. The results of the comprehensive analysis confirmed the applicability of the proposed differential MI-based receiver to a magnetic field.

Моделирование феррорезонансных режимов в нелинейных электрических цепях с учетом магнитного гистерезиса

Приведено решение задачи численного моделирования феррорезонансных режимов напряжений и токов в электрических цепях, возникающих при последовательном и параллельном соединении нелинейного индуктивного и емкостного элементов. Вебер-амперная характеристика индуктивного элемента задана с учетом гистерезиса. Известно, что феррорезонансные режимы возникают в электрических цепях, содержащих емкостные и нелинейные индуктивные элементы, в том числе силовые трансформаторы, дугогосящие реакторы, измерительные трансформаторы тока и напряжения, электродвигатели. Нелинейность характеристик индуктивных элементов служит причиной того, что при насыщении их магнитных систем происходит изменение дифференциальных индуктивностей, в результате возникают феррорезонансные, часто нештатные и даже аварийные режимы. Для имитационного моделирования магнитного гистерезиса использована модифицированная обратная модель Джайлса-Атертона. Численное интегрирование дифференциальных уравнений, описывающих динамические процессы в электрических цепях, выполнено явным методом Эйлера. Показано, что в результате феррорезонанса возникает тригеррный эффект, проявляющийся в форме скачкообразного изменения состояния цепи, вызванного неоднозначным характером вольт-амперной характеристики для входного напряжения и тока. Предложенный метод моделирования переходных и установившихся режимов в нелинейных электрических цепях с учетом магнитного гистерезиса может быть обобщен на случай произвольных цепей, в том числе, со сложной топологией.

Analytical Prototype Functions for Flux Linkage Approximation in Synchronous Machines

Physically motivated and analytical prototype functions are proposed to approximate the nonlinear flux linkages of nonlinear synchronous machines (SMs) in general; and reluctance synchronous machines (RSMs) and interior permanent magnet synchronous machines (IPMSMs) in particular. Such analytical functions obviate the need of huge lookup tables (LUTs) and are beneficial for optimal operation management and nonlinear control of such machines. The proposed flux linkage prototype functions are capable of mimicking the nonlinear self-axis and cross-coupling saturation effects of SMs. Moreover, the differentiable prototype functions allow to easily derive analytical expressions for the differential inductances by simple differentiation of the analytical flux linkage prototype functions. In total, two types of flux linkage prototype functions are developed. The first flux linkage approximation is rather simple and obeys the energy conservation rule for “symmetric” flux linkages of RSMs. With the gained knowledge, the second type of prototype functions is derived in order to achieve approximation flexibility necessary for SMs with permanent (or electrical) excitation with “unsymmetric” flux linkages due to the excitation offset. All proposed flux linkage prototype functions are continuously differentiable, obey the energy conservation rule and, as fitting results show, achieve a (very) high approximation accuracy over the whole operation range.

Diterpenoids from &lt;i&gt;Scutellaria barbata&lt;/i&gt; induce tumour-selective cytotoxicity by taking the brakes off apoptosis

Medicinal plants are an excellent source of structurally diverse, bio-active compounds with potential in the fight against cancer. One of the most promising is <italic>Scutellaria barbata,</italic> prescribed traditionally for the treatment of cancers<italic>.</italic> Scutebarbatine A is the major diterpenoid, produced in specialized large, peltate trichomes on leaves of <italic>S. barbata</italic>. It induces dose-dependent apoptosis, specifically in cancer cells. The major class of proteins down-regulated are pro-survival proteins, the Inhibitors of Apoptosis (IAPs), and IAP regulating proteins. We propose that scutebarbatine A works by releasing the molecular brakes (the IAPs) on apoptosis in cell death-evading cancer cells. Comparison between the cytotoxicity of methanolic extracts of <italic>S. barbata</italic> leaves and decoctions (Ban Zhi Lian) prepared traditionally, showed substantially different chemical compositions and differential induction of apoptosis. Analyses suggest polyvalency between the constituents in both extracts, and ways to produce enhanced chemopreventive preparations for the treatment of cancer.

Dynamics of seed dormancy and germination at high temperature stress is affected by priming and phytohormones in rapeseed (Brassica napus L.)

High temperature stress (HTS) imposes secondary dormancy (SD) also known as thermo-dormancy in many seeds. Priming by soil moisture however, may improve germination though under HTS it may compromise seed longevity. Knowledge of how HTS and priming affect dormancy status/viability loss of a particular crop seed species is essential in agriculture. Accordingly, control non-primed and hydro-primed seeds from Dk-xpower and Traper rapeseed cultivars with low and high potential for SD induction, respectively, were compared for germination behavior, response to GA and some phytohormone effectors under HTS. HTS reduced germination in non-primed Dk-xpower and Traper seeds mainly through the induction of thermo-inhibition/death and thermo-dormancy, respectively. Under HTS, GA3 application reduced thermo-dormancy in favor of thermo-inhibition only in Traper but the GA inhibitor paclobutrazol intensified thermo-dormancy in both cultivars. The ABA inhibitor, fluridone also reduced thermo-dormancy in favor of thermo-inhibition only in Traper. Thus, under HTS, GA biosynthesis is determinant in seed thermo-dormancy/thermo-inhibition dynamics. Hydropriming improved germination under HTS through reduced thermo-inhibition/death (Dk-xpower) and thermo-dormancy (Traper). Here, GA3 application increased death and compromised germination mainly in Dk-xpower. Paclubutrazol application however, increased thermo-dormancy by compromising thermo-inhibition/death in Traper. Overall, hydro-priming weakened seed phytohormonal germination responses. Controlled deterioration resulted in decreased longevity of hydro-primed seeds but induced SD in non-primed Traper seeds. Thus, down-regulation of GA biosynthesis may control differential induction of SD in rapeseed seeds under HTS while hydro-priming stimulates seed germination possibly through overcoming limitations in GA biosynthesis. The agricultural importance of these findings at the ecosystem scale is discussed.

Differential induction of antioxidant and anti-inflammatory phytochemicals in agitated micro-shoot cultures of Ajuga integrifolia Buch. Ham. ex D.Don with biotic elicitors

Ajuga integrifolia Buch. Ham. ex D.Don, a member of Lamiaceae family is pharmaceutically an active perennial herb widely spread in China, Afghanistan and Pakistan Himalayan region. The application of biotic elicitors is a promising approach to cover limitations of in vitro cell technology and challenges faced by pharmaceuticals industry for bulk up production. The current study involved the induction of agitated micro-shoot cultures with the aim to investigate the growth-promoting as well as phytochemicals enhancement role of yeast extract (YE) and pectin (PE). The results showed that both elicitors induced a considerable physiological response. Biomass accumulation was observed maximum (DW: 18.3 g/L) against PE (10 mg/L) compared to YE and control. Eleven secondary phytocompounds were quantified using high-performance liquid chromatography. PE (50 mg/L) was found to be effective in elicitation of rosmarinic acid (680.20 µg/g), chlorogenic acid (294.12 µg/g), apigenin (579.61 µg/g) and quercetin (596.89 µg/g). However, maximum caffeic acid (359.52 µg/g) and luteolin (546.12 µg/g accumulation was noted in PE (1 mg/L) treatment. Harpagide, aucubin, harpagoside and 8-O-acetyl-harpagoside production was suppressed by both elicitors except for YE (100 mg/L). Catalpol accumulation in micro-shoot cultures was also downregulated except in response to YE (50 and 100 mg/L). Antioxidant activity and anti-inflammatory activity remained higher under PE (50 mg/L) and YE (100 mg/L) respectively. Therefore, results suggested that Ajuga integrifolia micro-shoot cultures treated with yeast extract and pectin might be an efficient bio-factory to produce commercially potent specific secondary metabolites.

Mathematical Model and Characteristics of the Induction Motor with a Power Supply from a Current Source

. Methods and mathematical models for studying the modes and characteristics of the three-phase squirrel-cage induction motor with the power supplied to the stator winding from the current source have been developed. The specific features of the algorithms for calculating transients, steady-state modes and static characteristics are discussed. The results of the calculation of the processes and characteristics of induction motors with the power supply from the current source and the voltage source are compared. Steady-state and dynamic modes cannot be studied with a sufficient adequacy based on the known equivalent circuits; this requires using dynamic parameters, which are the elements of the Jacobi matrix of the system of equations of the electromechanical equilibrium. In the mathematical model, the state equations of the stator and rotor circuits are written in the fixed two-phase coordinate system. The transients are described by the system of differential equations of electrical equilibrium of the transformed circuits of the motor and the equation of the rotor motion and the steady-state modes by the system of algebraic equation. The developed algorithms are based on the mathematical model of the motor in which the magnetic path saturation and skin effect in the squirrel-cage bars are taken into consideration. The magnetic path saturation is accounted for by using the real characteristics of magnetizing by the main magnetic flux and leakage fluxes of the stator and rotor windings. Based on them, the differential inductances are calculated, which are the elements of the Jacobi matrix of the system of equations describing the dynamic modes and static characteristic. In order to take into account the skin effect in the squirrel-cage rotor, each bar along with the squirrel-cage rings is divided height-wise into several elements. As a result, the mathematical model considers the equivalent circuits of the rotor with different parameters which are connected by mutual inductance. The non-linear system of algebraic equations of electrical equilibrium describing the steady-state modes is solved by the parameter continuation method. To calculate the static characteristics, the differential method combined with the Newton’s Iterative refinement is used.

Depletion of Demethylase KDM6 Enhances Early Neuroectoderm Commitment of Human PSCs

Epigenetic modifications play a crucial role in neurogenesis, learning, and memory, but the study of their role in early neuroectoderm commitment from pluripotent inner cell mass is relatively lacking. Here we utilized the system of directed neuroectoderm differentiation from human embryonic stem cells and identified that KDM6B, an enzyme responsible to erase H3K27me3, was the most upregulated enzyme of histone methylation during neuroectoderm differentiation by transcriptome analysis. We then constructed KDM6B-null embryonic stem cells and found strikingly that the pluripotent stem cells with KDM6B knockout exhibited much higher neuroectoderm induction efficiency. Furthermore, we constructed a series of embryonic stem cell lines knocking out the other H3K27 demethylase KDM6A, and depleting both KDM6A and KDM6B, respectively. These cell lines together confirmed that KDM6 impeded early neuroectoderm commitment. By RNA-seq, we found that the expression levels of a panel of WNT genes were significantly affected upon depletion of KDM6. Importantly, the result that WNT agonist and antagonist could abolish the differential neuroectoderm induction due to manipulating KDM6 further demonstrated that WNT was the major downstream of KDM6 during early neural induction. Moreover, we found that the chemical GSK-J1, an inhibitor of KDM6, could enhance neuroectoderm induction from both embryonic stem cells and induced pluripotent stem cells. Taken together, our findings not only illustrated the important role of the histone methylation modifier KDM6 in early neurogenesis, providing insights into the precise epigenetic regulation in cell fate determination, but also showed that the inhibitor of KDM6 could facilitate neuroectoderm differentiation from human pluripotent stem cells.

C-di-GMP Induces COX-2 Expression in Macrophages in a STING-Independent Manner

Many pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide (LPS) and lipoteichoic acid, are potent immunostimulatory molecules and promote the expression of cyclooxygenase 2 (COX-2). While the production of COX-2, and ultimately prostaglandin E2, could be protective, persistent induction of COX-2 leads to inflamed environments that can result in septic shock and death. Bacterial derived cyclic dinucleotides (CDNs), c-di-GMP and c-di-AMP, are also PAMPs and have been shown to produce inflamed environments via the production of pro-inflammatory cytokines such as type I interferons. The well-characterized CDN immunostimulatory mechanism involves binding to stimulator of interferon genes (STING), which ultimately results in the phosphorylation of IRF3 or release of NF-κB to promote expression of type I IFN or pro-inflammatory cytokines. In this study, we sought to investigate if CDNs promote COX-2 expression. Using RAW macrophages as a model system, we reveal that c-di-GMP, but not c-di-AMP or the host-derived 2',3'-cGAMP, promotes COX-2 expression. Using analogues of CDNs, we show that the presence of two guanines and two 3',5'-phosphodiester linkages are requirements for the promotion of COX-2 expression by cyclic dinucleotides. Both c-di-GMP and LPS inductions of COX-2 expression in RAW macrophages are STING-independent and are regulated by Tpl2-MEK-ERK-CREB signaling; inhibitors of Tpl2, MEK, and ERK could attenuate COX-2 expression promoted by c-di-GMP. This work adds to the growing body of evidence that cyclic dinucleotides regulate pathways other than the STING-TBK1-IRF3 axis. Additionally, the differential COX-2 induction by c-di-GMP but not c-di-AMP or cGAMP suggests that the type and level of inflammation could be dictated by the nucleotide signature of the invading pathogen.

Enhancement of the HIV-1-Specific Immune Response Induced by an mRNA Vaccine through Boosting with a Poxvirus MVA Vector Expressing the Same Antigen.

Development of a vaccine against HIV remains a major target goal in the field. The recent success of mRNA vaccines against the coronavirus SARS-CoV-2 is pointing out a new era of vaccine designs against pathogens. Here, we have generated two types of mRNA vaccine candidates against HIV-1; one based on unmodified vectors and the other on 1-methyl-3′-pseudouridylyl modified vectors expressing a T cell multiepitopic construct including protective conserved epitopes from HIV-1 Gag, Pol and Nef proteins (referred to as RNA-TMEP and RNA-TMEPmod, respectively) and defined their biological and immunological properties in cultured cells and in mice. In cultured cells, both mRNA vectors expressed the corresponding protein, with higher levels observed in the unmodified mRNA, leading to activated macrophages with differential induction of innate immune molecules. In mice, intranodal administration of the mRNAs induced the activation of specific T cell (CD4 and CD8) responses, and the levels were markedly enhanced after a booster immunization with the poxvirus vector MVA-TMEP expressing the same antigen. This immune activation was maintained even three months later. These findings revealed a potent combined immunization regimen able to enhance the HIV-1-specific immune responses induced by an mRNA vaccine that might be applicable to human vaccination programs with mRNA and MVA vectors.