Establishment and application of a rapid visual diagnostic method for Streptococcus agalactiae based on recombinase polymerase amplification and lateral flow strips.

This study aims to establish a rapid diagnostic method for Streptococcus agalactiae (GBS) based on recombinase polymerase amplification (RPA) and lateral flow strips (LFS). The best primer pairs designed by SIP gene were screened according to the basic RPA reaction, then the probe was designed. The reaction condition was optimized based on the color development of the LFS detection line. To ascertain the reaction specificity, 10 common clinical pathogens and 10 clinical specimens of GBS were tested. Furthermore, the reaction sensitivity was assessed by utilizing a tenfold gradient dilution of GBS genomic DNA as templates. RPA-LFS method was compared to the qPCR assay and biochemical culture method for the Kappa consistency test. The RPA-LFS technique was able to complete the amplification process within 30 min and the results were observed on lateral flow strips. The method is highly sensitive, with a minimum detection limit of 1.31 ng for GBS. The RPA-LFS method showed consistent accuracy of results compared to qPCR and the culture-biochemical method. The establishment of this method is conducive to the development of on-site immediate detection, which can provide information for the timely development of a reasonable antimicrobial treatment plan, and has a greater potential for clinical application.

The emerging roles of miRNA-mediated autophagy in ovarian cancer.

Ovarian cancer is one of the common tumors of the female reproductive organs. It has a high mortality rate, is highly heterogeneous, and early detection and primary prevention are very complex. Autophagy is a cellular process in which cytoplasmic substrates are targeted for degradation in lysosomes through membrane structures called autophagosomes. The periodic elimination of damaged, aged, and redundant cellular molecules or organelles through the sequential translation between amino acids and proteins by two biological processes, protein synthesis, and autophagic protein degradation, helps maintain cellular homeostasis. A growing number of studies have found that autophagy plays a key regulatory role in ovarian cancer. Interestingly, microRNAs regulate gene expression at the posttranscriptional level and thus can regulate the development and progression of ovarian cancer through the regulation of autophagy in ovarian cancer. Certain miRNAs have recently emerged as important regulators of autophagy-related gene expression in cancer cells. Moreover, miRNA analysis studies have now identified a sea of aberrantly expressed miRNAs in ovarian cancer tissues that can affect autophagy in ovarian cancer cells. In addition, miRNAs in plasma and stromal cells in tumor patients can affect the expression of autophagy-related genes and can be used as biomarkers of ovarian cancer progression. This review focuses on the potential significance of miRNA-regulated autophagy in the diagnosis and treatment of ovarian cancer.

Crtc1 deficiency protects against sepsis-associated acute lung injury through activating akt signaling pathway.

BACKGROUND: Interplay between systemic inflammation and programmed cell death contributes to the pathogenesis of acute lung injury (ALI). cAMP-regulated transcriptional coactivator 1 (CRTC1) has been involved in the normal function of the pulmonary system, but its role in ALI remains unclear. METHODS AND RESULTS: We generated a Crtc1 knockout (KO; Crtc1-/-) mouse line. Sepsis-induced ALI was established by cecal ligation and puncture (CLP) for 24 h. The data showed that Ctrc1 KO substantially ameliorated CLP-induced ALI phenotypes, including improved lung structure destruction, reduced pulmonary vascular permeability, diminished levels of proinflammatory cytokines and chemokines, compared with the wildtype mice. Consistently, in lipopolysaccharide (LPS)-treated RAW264.7 cells, Crtc1 knockdown significantly inhibited the expression of inflammatory effectors, including TNF-α, IL-1ß, IL-6 and CXCL1, whereas their expressions were significantly enhanced by Crtc1 overexpression. Moreover, both Crtc1 KO in mice and its knockdown in RAW264.7 cells dramatically reduced TUNEL-positive cells and the expression of pro-apoptotic proteins. In contrast, Crtc1 overexpression led to an increase in the pro-apoptotic proteins and LPS-induced TUNEL-positive cells. Mechanically, we found that the phosphorylation of Akt was significantly enhanced by Crtc1 knockout or knockdown, but suppressed by Crtc1 overexpression. Administration of Triciribine, an Akt inhibitor, substantially blocked the protection of Crtc1 knockdown on LPS-induced inflammation and cell death in RAW264.7 cells. CONCLUSIONS: Our study demonstrates that CRTC1 contribute to the pathological processes of inflammation and apoptosis in sepsis-induced ALI, and provides mechanistic insights into the molecular function of CRTC1 in the lung. Targeting CRTC1 would be a promising strategy to treat sepsis-induced ALI in clinic.

The purinergic receptor P2X3 promotes facial pain by activating neurons and cytokines in the trigeminal ganglion.

The mechanism underlying allodynia/hyperalgesia caused by dental pulpitis has remained enigmatic. This investigation endeavored to characterize the influence of the purinergic receptor P2X3 on pain caused by experimental pulpitis and the mechanism involved. An experimental model of irreversible pulpitis was produced by the drilling and exposure of the dental pulp of the left upper first and second molars in rats, followed by measuring nociceptive responses in the oral and maxillofacial regions. Subsequently, neuronal activity and the expression of P2X3 and pertinent cytokines in the trigeminal ganglion (TG) were meticulously examined and analyzed. Histological evidence corroborated that significant pulpitis was produced in this model, which led to a distinct escalation in nociceptive responses in rats. The activation of neurons, coupled with the upregulated expression of c-fos, P2X3, p-p38, TNF-α and IL-1ß, was identified subsequent to the pulpitis surgery within the TG. The selective inhibition of P2X3 with A-317491 effectively restrained the abnormal allodynia/hyperalgesia following the pulpitis surgery and concurrently inhibited the upregulation of p-p38, TNF-α and IL-1ß within the TG. These findings suggest that the P2X3 signaling pathway plays a pivotal role in instigating and perpetuating pain subsequent to the induction of pulpitis in rats, implicating its association with the p38 MAPK signaling pathway and inflammatory factors.

The S-acylation cycle of transcription factor MtNAC80 influences cold stress responses in Medicago truncatula.

S-acylation is a reversible post-translational modification catalyzed by protein S-acyltransferases (PATs), and acyl protein thioesterases (APTs) mediate de-S-acylation. Although many proteins are S-acylated, how the S-acylation cycle modulates specific biological functions in plants is poorly understood. In this study, we report that the S-acylation cycle of transcription factor MtNAC80 is involved in the Medicago truncatula cold stress response. Under normal conditions, MtNAC80 localized to membranes through MtPAT9-induced S-acylation. In contrast, under cold stress conditions, MtNAC80 translocated to the nucleus through de-S-acylation mediated by thioesterases such as MtAPT1. MtNAC80 functions in the nucleus by directly binding the promoter of the glutathione S-transferase gene MtGSTU1 and promoting its expression, which enables plants to survive under cold stress by removing excess malondialdehyde and H2O2. Our findings reveal an important function of the S-acylation cycle in plants and provide insight into stress response and tolerance mechanisms.

Magnesium source with function of slowly releasing Mg and pH control for impurity-resistance synthesis ultra-large struvite from wastewater.

Struvite (MgNH4PO4·6H2O, Magnesium ammonium phosphate, MAP), recovered from wastewater, has potential application as a slow-release fertilizer. However, crystal size distribution (CSD) of recovered MAP typically lied in the range of 50-300 µm, due to fast nucleation rate and notably narrow metastable zone width (MSZW) of MAP, with purity levels 40-90 %. In order to control the rate of nucleation, a novel magnesium source with the form of MgHPO4·3H2O wrapped with Mg(OH)2 was prepared, referred to as P-3. This compound gradually released Mg2+ and PO43-, regulating solution concentration kept in MSZW to promote crystal growth. The inherent Mg(OH)2 within P-3 also acted as a pH regulator in wastewater, eliminating the necessity for additional acid or alkali adjustments during crystallization process. The MAP precipitated by P-3 exhibited an impressive CSD of 5000-7000 µm, with a maximum size reaching 10,000 µm. This represented the largest CSD reported in literature for recovered MAP from wastewater. The significance of the ultra-large MAP precipitated by P-3 lied in its enhanced resistance to impurity adsorption, resulting in MAP with a remarkable purity 97 %, under conditions of low heavy metal ion concentration approximately 5 mg/L. Furthermore, the removal efficiency of ammonia nitrogen (NH4+) can reach 92 %. In comparison, two other magnesium sources, soluble salts (MgCl2 and Na2HPO4, P-1) and a combination of insoluble salts (Mg(OH)2 and MgHPO4, P-2) were evaluated alongside P-3. The CSD of MAP precipitated from P-1, P-2 was both <100 µm, with purity levels of 90 and 92 % and NH4+ removal efficiency of 92 and 90 %, respectively. Importantly, the strategy of obtaining ultra-large size MAP from wastewater in this study provided novel insights into the crystallization of other insoluble salts with large sizes.

Efficient detection of Streptococcus pyogenes based on recombinase polymerase amplification and lateral flow strip.

PURPOSE: This article aims to establish a rapid visual method for the detection of Streptococcus pyogenes (GAS) based on recombinase polymerase amplification (RPA) and lateral flow strip (LFS). METHODS: Utilizing speB of GAS as a template, RPA primers were designed, and basic RPA reactions were performed. To reduce the formation of primer dimers, base mismatch was introduced into primers. The probe was designed according to the forward primer, and the RPA-LFS system was established. According to the color results of the reaction system, the optimum reaction temperature and time were determined. Thirteen common clinical standard strains and 14 clinical samples of GAS were used to detect the selectivity of this method. The detection limit of this method was detected by using tenfold gradient dilution of GAS genome as template. One hundred fifty-six clinical samples were collected and compared with qPCR method and culture method. Kappa index and clinical application evaluation of the RPA-LFS were carried out. RESULTS: The enhanced RPA-LFS method demonstrates the ability to complete the amplification process within 6 min at 33 °C. This method exhibits a high analytic sensitivity, with the lowest detection limit of 0.908 ng, and does not exhibit cross-reaction with other pathogenic bacteria. CONCLUSIONS: The utilization of RPA and LFS allows for efficient and rapid testing of GAS, thereby serving as a valuable method for point-of-care testing.

Anti-papillary thyroid carcinoma effects of dioscorea bulbifera L. through ferroptosis and the PI3K/AKT pathway based on network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Papillary thyroid carcinoma (PTC) is the predominant form of thyroid cancer with a rising global incidence. Despite favorable prognoses, a significant recurrence rate persists. Dioscorea bulbifera L. (DBL), a traditional Chinese medicine, has been historically used for thyroid-related disorders. However, its therapeutic effects and mechanisms of action on PTC remain unclear. AIM OF THE STUDY: To explore the potential therapeutic effects, principal active components, and molecular mechanisms of DBL in the treatment of PTC through network pharmacology and molecular docking, with experimental validation conducted to corroborate these findings. MATERIALS AND METHODS: The Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) was utilized as a systematic tool for collecting and screening the phytochemical components of DBL, and for establishing associations between these components and molecular targets. Based on this, network data was visually processed using Cytoscape software (version 3.8.0). Concurrently, precise molecular docking studies of the principal active components of DBL and their corresponding targets were conducted using Autodock software. Additionally, PTC-related genes were selected through the GeneCards and GEO databases. We further employed the DAVID bioinformatics resources to conduct comprehensive Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses on the intersecting genes between DBL and PTC. These analyses aid in predicting the potential therapeutic actions of DBL on PTC and its mechanisms of action. To validate these findings, corresponding in vitro experimental studies were also conducted. RESULTS: In this investigation, 14 bioactive compounds of DBL and 195 corresponding molecular targets were identified, with 127 common targets shared between DBL and PTC. Molecular docking revealed strong binding affinities between major bioactive compounds and target proteins. GO enrichment analysis unveiled key processes involved in DBL's action. KEGG analysis highlighted DBL's modulation of the PI3K/AKT signaling pathway. Experimental outcomes demonstrated DBL's potential in inhibiting PTC cell proliferation and migration, suppressing PI3K/AKT pathway activation, and promoting ferroptosis. CONCLUSION: In conclusion, DBL offers a multifaceted therapeutic approach for PTC, targeting multiple molecular entities and influencing diverse biological pathways. Network pharmacology and molecular docking shed light on DBL's potential utility in PTC treatment, substantiated by experimental validation. This study contributes valuable insights into using DBL as a promising therapeutic agent for PTC management.

Photosynthetic System Based on a Polyoxometalate-Based Dehydrated Metal-Organic Framework for Nitrogen Fixation.

In nature, biological nitrogen fixation is accomplished through the π-back-bonding mechanism of nitrogenase, which poses significant challenges for mimic artificial systems, thanks to the activation barrier associated with the N≡N bond. Consequently, this motivates us to develop efficient and reusable photocatalysts for artificial nitrogen fixation under mild conditions. We employ a charge-assisted self-assembly process toward encapsulating one polyoxometalate (POM) within a dehydrated Zr-based metal-organic framework (d-UiO-66) exhibiting nitrogen photofixation activities, thereby constructing an enzyme-mimicking photocatalyst. The dehydration of d-UiO-66 is favorable for facilitating nitrogen chemisorption and activation via the unpaired d-orbital electron at the [Zr6O6] cluster. The incorporation of POM guests enhanced the charge separation in the composites, thereby facilitating the transfer of photoexcited electrons into the π* antibonding orbital of chemisorbed N2 for efficient nitrogen fixation. Simultaneously, the catalytic efficiency of SiW9Fe3@d-UiO-66 is enhanced by 9.0 times compared to that of d-UiO-66. Moreover, SiW9Fe3@d-UiO-66 exhibits an apparent quantum efficiency (AQE) of 0.254% at 550 nm. The tactics of "working-in-tandem" achieved by POMs and d-UiO-66 are extremely vital for enhancing artificial ammonia synthesis. This study presents a paradigm for the development of an efficient artificial catalyst for nitrogen photofixation, aiming to mimic the process of biological nitrogen fixation.

Effects of microbial agents and corn protein ferment on physiological characteristics in leaves and yield of tomato.

Premature senescence in greenhouse tomato is a significant challenge under long-season cultivation, due to suboptimal nutrient management during growth periods. We investigated the effects of microbial agents (T1), corn protein ferment (T2), and their combined application (T3) on photosynthetic characteristics and antioxidant enzyme activities in 'Saint Laurent 3689' tomato leaves, normal management served as the control (CK). We explored the physiological mechanism of delaying leaf senescence. Results showed that applying microbial agents or corn protein ferment individually led to improvements in leaf photosynthetic characteristics and antioxidant enzyme activities. The combined application yielded superior outcomes. Eighty days post the combined application of microbial agents and corn protein ferment (T3), chlorophyll (a+b) content, net photosynthetic rate, and the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in leaves increased by 16.4%, 30.9%, 23.4%, 33.0% and 40.3%, respectively, compared with the CK. Furthermore, plant height and stem diameter increased by 8.2% and 7.0%, while the total yield exhibited a significant increase of 9.9% compared with the CK 210 days post-treatment. In conclusion, the combined application of microbial agents and corn protein ferment has promising potential in enhancing chlorophyll content, net photosynthetic rate, and the activities of SOD, POD and CAT in tomato leaves. This approach effectively delayed leaf senescence, thereby promoting tomato growth and remarkably increasing the yield.

Longitudinal evaluation of innate immune responses to three doses of CoronaVac vaccine.

The adaptive immune responses induced by inactivated COVID-19 vaccine has been extensively studied. However, few studies have analyzed the impact of COVID-19 vaccination on innate immune cells. Here in this study, we recruited 62 healthcare workers who received three doses of CoronaVac vaccine and longitudinally profiled the alterations of peripheral monocytes and NK cells during vaccination. The results showed that both the monocyte and NK cell subsets distribution were altered, although the frequencies of the total monocyte and NK cells remained stable during the vaccination. Additionally, we found that both the 2nd and 3rd dose of CoronaVac vaccination elicited robust IFN-γ-producing NK cell response. Our data provided necessary insights on innate immune responses in the context of three homologous CoronaVac dose vaccination, and supplied immunological basis for the future design of inactivated vaccines against SARS-CoV-2 or other viruses.

Neutralizing activity of a third dose of CoronaVac against Omicron subvariants within a 20-month follow-up study.

The durability of antibody responses induced by the three-dose of CoronaVac vaccination, especially against SARS-CoV-2 Omicron subvariants, remains unclear. Here in our study, 160 plasma samples from 32 healthy individuals who received three doses of CoronaVac were longitudinally tracked for a period of 20 months. The results showed that a third homologous dose of CoronaVac efficiently increased the SARS-CoV-2 IgG and neutralizing antibody titers and enhanced neutralization activity against Omicron subvariants. The levels of IgG and neutralizing antibody declined from peak levels but remained detectable in most subjects over the course of the next 10-12 months. However, most of the individuals kept neutralizing titers against ancestral Wuhan-Hu-1, while they lost their neutralizing activities against Omicron B.1.1.529, BA.2, BA.4/BA.5, and BA.2.75.2 subvariants at 10-12 months post the third vaccination. Our results suggest that a fourth dose of vaccine may be necessary for uninfected individuals to confer higher neutralization against emerging Omicron subvariants.

Synergistic Enhancement of Photocatalytic CO2 Reduction by Built-in Electric Field/Piezoelectric Effect and Surface Plasmon Resonance via PVDF/CdS/Ag Heterostructure.

Photocatalytic reduction of CO2 using solar energy is an effective means to achieve carbon neutrality. However, the photocatalytic efficiency still requires improvements. In this study, polyvinylidene fluoride (PVDF) ferroelectric/piezoelectric nanofiber membranes are prepared by electrospinning. Cadmium sulfide (CdS) nanosheets are assembled in situ on the surface of PVDF based on coordination between F- and Cd2+ , and then Ag nanoparticles are deposited on CdS. Because of the synergistic effect between localized surface plasmon resonance of Ag nanoparticles and the built-in electric field of PVDF, the CO2 photocatalytic reduction efficiency using PVDF/CdS/Ag under visible light irradiation is significantly higher than that of any combination of CdS, CdS/Ag, or PVDF/CdS. Under micro-vibration to simulate air flow, the CO2 reduction efficiency of PVDF/CdS/Ag is three times higher than that under static conditions, reaching 240.4 µmol g-1 h-1 . The piezoelectric effect caused by micro-vibrations helps prevent the built-in electric field from becoming saturated with carriers and provides a continuous driving force for carrier separation.

An improved recombinase polymerase amplification assay for the visual detection of Staphylococcus epidermidis with lateral flow strips.

Staphylococcus epidermidis is an opportunistic pathogenic microorganism that is an important cause of cross-infection in hospitals. The development of rapid and effective detection techniques is important for its control. The application of traditional identification and PCR-based methods is limited by their requirements for both laboratory instrumentation and trained personnel. To overcome this issue, we developed a fast detection approach for S. epidermidis that was based on recombinase polymerase amplification (RPA) and lateral flow strips (LFS). First, five pairs of primers were designed for molecular diagnosis using the sesB gene as the target, and were screened for their amplification performance and the formation of primer dimers. Specific probes were then designed based on the best primer pairs screened, which were susceptible to primer-dependent artifacts and generated false-positive signals when used for LFS detection. This weakness of the LFS assay was overcome by modifying the sequences of the primers and probes. The efficacy of these measures was rigorously tested, and improved the RPA-LFS system. Standardized systems completed the amplification process within 25 min at a constant temperature of 37 °C, followed by visualization of the LFS within 3 min. The approach was very sensitive (with a detection limit of 8.91 CFU/µL), with very good interspecies specificity. In the analysis of clinical samples, the approach produced results consistent with PCR and 97.78% consistent with the culture-biochemical method, with a kappa index of 0.938. Our method was rapid, accurate, and less dependent on equipment and trained personnel than traditional methods, and provided information for the timely development of rational antimicrobial treatment plans. It has high potential utility in clinical settings, particularly in resource-constrained locations.

A rapid and visual detection of Staphylococcus haemolyticus in clinical specimens with RPA-LFS.

Staphylococcus haemolyticus (S. haemolyticus), which is highly prevent in the hospital environment, is an etiological factor for nosocomial infections. Point-of-care rapid testing (POCT) of S. haemolyticus is not possible with the currently used detection methods. Recombinase polymerase amplification (RPA) is a novel isothermal amplification technology with high sensitivity and specificity. The combination of RPA and lateral flow strips (LFS) can achieve rapid pathogen detection, enabling POCT. This study developed an RPA-LFS methodology using a specific probe/primer pair to identify S. haemolyticus. A basic RPA reaction was performed to screen the specific primer from 6 primer pairs targeting mvaA gene. The optimal primer pair was selected based on agarose gel electrophoresis, and the probe was designed. To eliminate false-positive results caused by the byproducts, base mismatches were introduced in the primer/probe pair. The improved primer/probe pair could specifically identify the target sequence. To explore the optimal reaction conditions, the effects of reaction temperature and duration of the RPA-LFS method were systematically investigated. The improved system enabled optimal amplification at 37 °C for 8 min, and the results were visualized within 1 min. The S. haemolyticus detection sensitivity of the RPA-LFS method, whose performance was unaffected by contamination with other genomes, was 0.147 CFU/reaction. Furthermore, we analyzed 95 random clinical samples with RPA-LFS, quantitative polymerase chain reaction (qPCR), and traditional bacterial-culture assays and found that the RPA-LFS had 100% and 98.73% compliance rates with the qPCR and traditional culture method, respectively, which confirms its clinical applicability. In this study, we designed an improved RPA-LFS assay based on the specific probe/primer pair for the detection of S. haemolyticus via rapid POCT, free from the limitations of the precision instruments, helping to make diagnoses and treatment decisions as soon as possible.

Artesunate alleviates intestinal ischemia/reperfusion induced acute lung injury via up-regulating AKT and HO-1 signal pathway in mice.

Acute Lung injury (ALI) is a common complication following intestinal ischemia/reperfusion (II/R) injury that can lead to acute respiratory distress syndrome (ARDS) a fatal illness for there is no specific therapy. The semisynthetic artemisinin Artesunate (Art) extracted from Artemisia annua has been found lots of pharmaceutical effects such as anti-malaria, anti-inflammatory, and anti-apoptosis. This study aimed to investigate the effect of Artesunate on intestinal ischemia/reperfusion and the mechanism of how Artesunate works in mice. To establish the II/R model, the C57BL/c mice were subjected to occlude superior mesenteric artery (SMA) for 45 min and 120 min reperfusion, and the lung tissue was collected for examination. Severe lung injury occurred during the II/R, meanwhile Art pretreatment decreased the lung injury score, wet/dry ratio, the level of MDA, MPO, IL-1ß, TNFα, CXCL1, MCP-1, the TUNEL-positive cells, Bax and Cleaved-Caspase3 protein expression obviously, and increased the activity of SOD and the expression of Bcl-2. In addition, the protein of P-AKT and HO-1 were upregulated during the Art pretreatment. Then the AKT inhibitor Triciribin and HO-1 inhibitor Tin-protoporphyrin IX were administered which reversed the protein expression of apoptosis, AKT and HO-1. Our study suggests that Art mitigated the II/R induced acute lung injury by targeting the oxidative stress, inflammatory response and apoptosis which is associated with the activating of AKT and HO-1, providing novel insights into the therapeutic candidate for the treatment of II/R induced acute lung injury.

Photochemical Ammonia Synthesis over Reduced Polyoxovanadate-Intercalated Defective ZnAl Layered Double Hydroxide Nanosheets.

The exploration of efficient and stable N2 fixation photocatalysts featuring a broad absorption spectrum and N2 fixation active sites has become specifically conspicuous. Herein, a series of reduced polyoxovanadates (POVs) were intercalated into copper-induced ZnAl layered double hydroxide (0.5%-ZnAl LDH) nanosheets with oxygen vacancies via an anion exchange strategy toward green ammonia production. The intervalence charge transfer arising from mixed-valence POV materials is responsible for its light-harvesting behavior, and the LDHs lay the foundation for the chemical adsorption and activation process of nitrogen molecules; both contributions facilitate the nitrogen photofixation performance of such composite materials. As predicted, the catalytic efficiency of V34/0.5%-ZnAl is 7.0 times higher than 0.5%-ZnAl LDH. Therefore, such an all-inorganic system exhibits an apparent quantum efficiency of 0.3137% at 500 nm. The strategy of "working in tandem" established by POV-based light-absorber species and oxygen vacancies as the sites for N2 activation is extremely vital for enhanced ammonia formation. This work opens up a versatile insight for the rational design of an efficient photo-driven nitrogen-reduction composite catalyst toward sustainable ammonia production compared to the industrial Haber-Bosch process.

Longitudinal analysis of memory Tfh cells and antibody response following CoronaVac vaccination.

The inactivated vaccine CoronaVac is one of the most widely used COVID-19 vaccines globally. However, the longitudinal evolution of the immune response induced by CoronaVac remains elusive compared with other vaccine platforms. Here, we recruited 88 healthy individuals who received 3 doses of CoronaVac vaccine. We longitudinally evaluated their polyclonal and antigen-specific CD4+ T cells and neutralizing antibody response after receiving each dose of vaccine for over 300 days. Both the second and third doses of vaccine induced robust spike-specific neutralizing antibodies, with a third vaccine further increasing the overall magnitude of antibody response and neutralization against Omicron sublineages B.1.1.529, BA.2, BA.4/BA.5, and BA.2.75.2. Spike-specific CD4+ T cells and circulating T follicular helper (cTfh) cells were markedly increased by the second and third dose of CoronaVac vaccine, accompanied by altered composition of functional cTfh cell subsets with distinct effector and memory potential. Additionally, cTfh cells were positively correlated with neutralizing antibody titers. Our results suggest that CoronaVac vaccine-induced spike-specific T cells are capable of supporting humoral immunity for long-term immune protection.

The thioesterase APT1 is a bidirectional-adjustment redox sensor.

The adjustment of cellular redox homeostasis is essential in when responding to environmental perturbations, and the mechanism by which cells distinguish between normal and oxidized states through sensors is also important. In this study, we found that acyl-protein thioesterase 1 (APT1) is a redox sensor. Under normal physiological conditions, APT1 exists as a monomer through S-glutathionylation at C20, C22 and C37, which inhibits its enzymatic activity. Under oxidative conditions, APT1 senses the oxidative signal and is tetramerized, which makes it functional. Tetrameric APT1 depalmitoylates S-acetylated NAC (NACsa), and NACsa relocates to the nucleus, increases the cellular glutathione/oxidized glutathione (GSH/GSSG) ratio through the upregulation of glyoxalase I expression, and resists oxidative stress. When oxidative stress is alleviated, APT1 is found in monomeric form. Here, we describe a mechanism through which APT1 mediates a fine-tuned and balanced intracellular redox system in plant defence responses to biotic and abiotic stresses and provide insights into the design of stress-resistant crops.