Enhanced potency of an IgM-like nanobody targeting conserved epitope in SARS-CoV-2 spike N-terminal domain.

Almost all the neutralizing antibodies targeting the receptor-binding domain (RBD) of spike (S) protein show weakened or lost efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged or emerging variants, such as Omicron and its sub-variants. This suggests that highly conserved epitopes are crucial for the development of neutralizing antibodies. Here, we present one nanobody, N235, displaying broad neutralization against the SARS-CoV-2 prototype and multiple variants, including the newly emerged Omicron and its sub-variants. Cryo-electron microscopy demonstrates N235 binds a novel, conserved, cryptic epitope in the N-terminal domain (NTD) of the S protein, which interferes with the RBD in the neighboring S protein. The neutralization mechanism interpreted via flow cytometry and Western blot shows that N235 appears to induce the S1 subunit shedding from the trimeric S complex. Furthermore, a nano-IgM construct (MN235), engineered by fusing N235 with the human IgM Fc region, displays prevention via inducing S1 shedding and cross-linking virus particles. Compared to N235, MN235 exhibits varied enhancement in neutralization against pseudotyped and authentic viruses in vitro. The intranasal administration of MN235 in low doses can effectively prevent the infection of Omicron sub-variant BA.1 and XBB in vivo, suggesting that it can be developed as a promising prophylactic antibody to cope with the ongoing and future infection.

Neutrophil-to-lymphocyte ratio and monocyte-to-eosinophil ratio as prognostic indicators for advanced nasopharyngeal carcinoma.

OBJECTIVE: To determine the predictive value of the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), neutrophil-to-eosinophil ratio (NER), lymphocyte-to-eosinophil ratio (LER), monocyte-to-eosinophil ratio (MER), systemic inflammatory response index (SIRI), and ratio of inflammatory cells before and after treatment for predicting survival in advanced nasopharyngeal carcinoma (NPC) and to provide a reference for treatment. METHODS: A retrospective review of 70 patients was performed. Serological indexes were obtained by drawing blood before and after systemic therapy. The cutoff values of these indexes were determined by receiver operating characteristic (ROC) curves. The prognostic value of the indexes for overall survival (OS) and distant metastasis free survival (DMFS) was evaluated. RESULTS: Survival analysis showed that a smaller pretreatment LMR value was associated with poor OS; larger pretreatment NER, LER, MER, and SIRI values were associated with poor OS; a smaller posttreatment LMR value was associated with poor OS; larger posttreatment NLR, NER, MER, and SIRI values were associated with poor OS; a smaller pretreatment LMR value was associated with poor DMFS; larger pretreatment NLR, NER, LER, and MER values were associated with poor DMFS; and larger posttreatment NLR, NER, LER, and MER values were associated with poor DMFS. Furthermore, a larger neutrophil after treatment-to-neutrophil before treatment ratio was associated with poor OS and DMFS. Logistic regression analysis showed that pretreatment MER and posttreatment NLR were independent predictors of OS in patients with advanced NPC; moreover, pretreatment and posttreatment MER and NLR were independent prognostic factors for DMFS in patients with advanced NPC. CONCLUSIONS: The NLR, NER and MER can be used to predict survival in advanced NPC patients. Eosinophils might be one of the factors for the good prognosis of NPC patients. In addition, an increased number of neutrophils after treatment may indicate a favorable prognosis.

Serum Proteomic Analysis Revealed Biomarkers for Eosinophilic Chronic Rhinosinusitis with Nasal Polyps Pathophysiology.

Background: Individuals with eosinophilic chronic rhinosinusitis with nasal polyps(eCRSwNP) exhibited worse outcomes and higher postoperative recurrence rates. This study aimed to identify biomarkers that can aid in the early differentiation of eCRSwNP and enhance our comprehension of its pathophysiology. Methods: We recruited two independent cohorts. In the discovery cohort, CRSwNP was categorized into eCRSwNP and non-eosinophilic CRSwNP(neCRSwNP), and serum proteomics was performed to identify differentially expressed proteins between the two groups. These candidate proteins were chosen and confirmed in the validation cohort using an enzyme-linked immunosorbent assay (ELISA), Western blot (WB), quantitative real time-polymerase chain reaction (qRT-PCR), immunofluorescence (IF), and their predictive values and associations with tissue eosinophilic pathophysiology were evaluated. Results: We identified a total of 39 differential proteins between the two groups, including 20 proteins upregulated and 19 downregulated in the eCRSwNP group. Further validation was conducted on the top 5 proteins that were up or down-regulated. Results from the ELISA showed that levels of serum MRC1, CDH13, and MMP2 were significantly higher, TRIM28 was lower in the eCRSwNP group compared to the neCRSwNP group (all P<0.05), and serum MRC1 (AUC=0.742, P<0.001) and MMP2 (AUC=0.766, P<0.001) levels exhibited promising predicting values for eCRSwNP. Moreover, qRT-PCR and WB analysis found that MMP2 and MRC1 expressions were enhanced in the eCRSwNP group compared to the neCRSwNP group (all P<0.01), and their levels were positively correlated with the number and percentages of tissue eosinophils (all P<0.01). The IF suggested that MMP2 and MRC1 were overexpressed in the nasal polyps tissues of eCRSwNP patients, and MMP2 was mainly located on eosinophils. Conclusion: Circulating proteins identified by proteomics could serve as potential preoperative biomarkers for distinguishing eCRSwNP. Among them, MMP2 was enhanced in eCRSwNP and correlated with tissue eosinophilia, which provided valuable insights into the pathophysiology of eCRSwNP.

Clinical efficacy and risk factors for suction curettage and hysteroscopy in patients with type I and II cesarean scar pregnancy.

OBJECTIVE: To investigate the clinical efficacy and evaluate risk factors for suction curettage (SC) and hysteroscopy in the treatment of type I and II cesarean scar pregnancy (CSP). METHODS: This was a retrospective study including 100 women diagnosed with type I/II CSP. Patients were treated with either ultrasound-guided SC (SC group) or hysteroscopy resection (surgery group). The success rates, mean operation time, hospitalization duration, hospitalization cost, risk factors, adverse events, and complications were analyzed. RESULTS: The success rate of the SC and surgery groups were 85% and 100%, respectively, and the difference was statistically significant (P = 0.032). There was one case of type I CSP and eight cases of type II CSP that failed SC treatment. No failed cases were found in the surgery group. Analysis of the causes of treatment failure revealed that diameter of the gestational sac was a risk factor for SC failure (odds ratio, 19.66 [95% confidence interval {CI}, 1.70-227.72], P = 0.017). Comparing the clinical outcomes between the SC and surgery groups, although the mean operation time of the SC group was significantly shorter than the surgery group (15 [CI, 15-20] vs. 30 [CI, 27-40], P = 0.001), the cost and duration of hospitalization were significantly lower in the surgery group than that in the SC group. No significant differences were observed for adverse events and complications between the two groups (P > 0.05). CONCLUSION: Hysteroscopy is an effective and economical method for treating type I/II CSP. Moreover, SC is not recommended for patients with type I/II CSP with a gestation age ≥8 weeks.

Apigenin analogs as α-glucosidase inhibitors with antidiabetic activity.

This study investigated the inhibitory potential of a series of synthesized compounds (L1-L27) on α-glucosidase. Among them, compound L22 showed significant inhibitory effect. Through enzymatic kinetics studies, we demonstrated that L22 acts via a non-competitive inhibition mode with a Ki value of 2.61 µM, highlighting its high affinity for the enzyme. Molecular docking studies revealed the formation of hydrogen bonds between L22 and α-glucosidase and diverse interactions with neighboring amino acid residues. Furthermore, molecular dynamics simulations confirmed the stability of the L22-α-glucosidase complex. In a mouse model of type 2 diabetes, treatment with L22 significantly lowered fasting blood glucose levels, and reduced insulin resistance, suggesting its potential as a therapeutic agent for type 2 diabetes. Furthermore, L22 showed a protective effect against oxidative stress in the liver and alleviated liver and pancreatic abnormalities. These results provide valuable insights into the mechanism of action of L22 and its potential applications to treat type 2 diabetes, and improve liver health.

Cross-species recognition of bat coronavirus RsYN04 and cross-reaction of SARS-CoV-2 antibodies against the virus.

Following the outbreak of coronavirus disease 2019 (COVID-19), several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related coronaviruses have been discovered. Previous research has identified a novel lineage of SARS-CoV-2-related CoVs in bats, including RsYN04, which recognizes human angiotensin-converting enzyme 2 (ACE2) and thus poses a potential threat to humans. Here, we screened the binding of the RsYN04 receptor-binding domain (RBD) to ACE2 orthologs from 52 animal species and found that the virus showed a narrower ACE2-binding spectrum than SARS-CoV-2. However, the presence of the T484W mutation in the RsYN04 RBD broadened its range. We also evaluated 44 SARS-CoV-2 antibodies targeting seven epitope communities in the SARS-CoV-2 RBD, together with serum obtained from COVID-19 convalescents and vaccinees, to determine their cross-reaction against RsYN04. Results showed that no antibodies, except for the RBD-6 and RBD-7 classes, bound to the RsYN04 RBD, indicating substantial immune differences from SARS-CoV-2. Furthermore, the structure of the RsYN04 RBD in complex with cross-reactive antibody S43 in RBD-7 revealed a potently broad epitope for the development of therapeutics and vaccines. Our findings suggest RsYN04 and other viruses belonging to the same clade have the potential to infect several species, including humans, highlighting the necessity for viral surveillance and development of broad anti-coronavirus countermeasures.

Detection of HER-3 with an AlGaN/GaN-Based Ion-Sensitive Heterostructure Field Effect Transistor Biosensor.

Human epidermal growth factor receptor-3 (HER-3) plays a key role in the growth and metastasis of cancer cells. The detection of HER-3 is very important for early screening and treatment of cancer. The AlGaN/GaN-based ion-sensitive heterostructure field effect transistor (ISHFET) is sensitive to surface charges. This makes it a promising candidate for the detection of HER-3. In this paper, we developed a biosensor for the detection of HER-3 with AlGaN/GaN-based ISHFET. The AlGaN/GaN-based ISHFET biosensor exhibits a sensitivity of 0.53 ± 0.04 mA/dec in 0.01 M phosphate buffer saline (1× PBS) (pH = 7.4) solution with 4% bovine serum albumin (BSA) at a source and drain voltage of 2 V. The detection limit is 2 ng/mL. A higher sensitivity (2.20 ± 0.15 mA/dec) can be achieved in 1× PBS buffer solution at a source and drain voltage of 2 V. The AlGaN/GaN-based ISHFET biosensor can be used for micro-liter (5 µL) solution measurements and the measurement can be performed after incubation of 5 min.

Two pan-SARS-CoV-2 nanobodies and their multivalent derivatives effectively prevent Omicron infections in mice.

With the widespread vaccinations against coronavirus disease 2019 (COVID-19), we are witnessing gradually waning neutralizing antibodies and increasing cases of breakthrough infections, necessitating the development of drugs aside from vaccines, particularly ones that can be administered outside of hospitals. Here, we present two cross-reactive nanobodies (R14 and S43) and their multivalent derivatives, including decameric ones (fused to the immunoglobulin M [IgM] Fc) that maintain potent neutralizing activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after aerosolization and display not only pan-SARS-CoV-2 but also varied pan-sarbecovirus activities. Through respiratory administration to mice, monovalent and decameric R14 significantly reduce the lung viral RNAs at low dose and display potent pre- and post-exposure protection. Furthermore, structural studies reveal the neutralizing mechanisms of R14 and S43 and the multiple inhibition effects that the multivalent derivatives exert. Our work demonstrates promising convenient drug candidates via respiratory administration against SARS-CoV-2 infection, which can contribute to containing the COVID-19 pandemic.

Blood eosinophil count in the diagnosis of allergic-like rhinitis with chronic rhinosinusitis.

BACKGROUND: Allergic rhinitis (AR) and nonallergic rhinitis (NAR) often are comorbid with chronic rhinosinusitis (CRS). Finding a convenient test that distinguishes these complex conditions is helpful for effective treatment. We aimed to analyse blood parameter differences between AR and NAR patients with/without CRS. METHODS: Eight hundred thirteen patients, including AR and NAR with different conditions [CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP)] were analysed in this retrospective study. Patients with a nasal deviation alone were included as healthy controls (HC). Receiver operating characteristic analysis was used to assess the value of blood parameters for diagnosing AR or NAR with/without CRS. RESULTS: Compared to nonallergic-like rhinitis (HC, CRSwNP and CRSsNP), the blood eosinophil count was significantly increased in the allergic-like rhinitis groups, except for NAR-CRSsNP (AR, AR-CRSwNP, AR-CRSsNP, NAR and NAR-CRSwNP). The NAR-CRSsNP group had a higher level of eosinophils than the HC and CRSsNP groups. Among allergic-like rhinitis patients, eosinophils were higher in allergic-like rhinitis patients with CRSwNP (AR-CRSwNP and NAR-CRSwNP) than in allergic-like rhinitis patients without CRSwNP (AR, AR-CRSsNP, NAR and NAR-CRSsNP). However, no difference in blood eosinophils was observed between AR and NAR. There was also no difference among nonallergic-like rhinitis patients. Similar findings were found for the blood eosinophil proportion. Furthermore, the blood eosinophil count was a good predictor of allergic-like rhinitis, especially allergic-like rhinitis with CRSwNP. CONCLUSION: The blood eosinophil count and proportion may be good diagnostic predictors of allergic-like rhinitis but cannot differentiate between AR and NAR. This indicator may be much better in predicting allergic-like rhinitis with CRSwNP.

Antagonism of m3 Alleviates Type 2 Inflammation in Allergic Rhinitis Mice.

BACKGROUND: Type 2 immune cells play a pivotal role in allergic rhinitis (AR). Increasing evidence shows that inhibition of cholinergic nerve activity decreases the severity of airway diseases including asthma and AR. However, the role of the cholinergic receptor muscarinic 3 (m3) in type 2 inflammation in AR is unknown. OBJECTIVE: We aimed to investigate the effect of m3 on the type 2 immune response, including both T helper 2 (Th2)-mediated and type 2 innate lymphocyte (ILC2)-mediated inflammation, in AR. METHODS: Peripheral blood mononuclear cells (PBMCs) from human were cultured in vitro. Treatment with the m3 antagonist 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP) was used. The percentages of Th2 and ILC2 cells in PBMCs were evaluated by flow cytometry. AR mouse models were established by house dust mite (HDM) sensitization, and treated with tiotropium intranasally. The expression of Th2 cytokines, ILC2 cytokines and related factors in the nasal mucosa was assessed by immunohistochemistry and quantitative real-time polymerase chain reaction. Serum HDM-specific immunoglobulin E (sIgE) level was detected by enzyme-linked immunosorbent assay. RESULTS: Both Th2 and ILC2 percentages in PBMCs were decreased after 4-DAMP treatment. Similarly, the levels of Th2 cytokines (interleukin 4 [IL-4] and IL-13) and ILC2 cytokines and related factors (IL-25, IL-33, GATA3 and RORα) were significantly decreased in the nasal mucosa of AR mice after tiotropium treatment. Furthermore, tiotropium treatment decreased the nasal symptom score, the serum sIgE level and eosinophil infiltration in AR mice. In addition, tiotropium decreased phospholipase Cγ1 (PLCγ1), PLCγ2, nuclear factor of activated T cell 1 (NFATc1), and NFATc2 mRNA levels in AR mice. CONCLUSION: Antagonism of m3 alleviated type 2 inflammation in the nasal mucosa of AR mice.

Exosomes loaded with circPARD3 promotes EBV-miR-BART4-induced stemness and cisplatin resistance in nasopharyngeal carcinoma side population cells through the miR-579-3p/SIRT1/SSRP1 axis.

OBJECTIVE: To explore the effects of exosomes loaded with circular RNA PARD3 on EBV-miR-BART4-induced stemness and resistance of cisplatin in nasopharyngeal carcinoma side population (NPC-SP) cells through the miR-579-3p/SIRT1/SSRP1 axis. METHODS: Sixty-five cancer tissues and 65 noncancerous tissues were collected from NPC patients or patients with rhinitis. The expressions of circPARD3, miR-579-3p, SIRT1, and SSRP1 were detected by qRT-PCR, western blot, or immunohistochemistry. In vivo tumor formation assay was performed in nude mice. Immunofluorescence and qRT-PCR were conducted for the determination of CD44 and CD133 expressions, and flow cytometry combined with Hoechst 33,342 dye efflux for identifying SP cells, CCK-8 and EdU assays for cell proliferation, and Transwell assay for migration and invasion. RESULTS: CircPARD3, SIRT1, and SSRP1 were upregulated while miR-579-3p was downregulated in NPC tissues and cells. CircPARD3 was positively correlated with the expressions of SIRT1 and SSRP1, and miR-579-3p was negatively correlated with circPARD3, SIRT1, and SSRP1. Exosomes loaded with circPARD3 promoted EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells, while miR-579-3p reversed the effect of exosomal circPARD3 on EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells. Additionally, miR-579-3p suppressed EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells by regulating SIRT1. SIRT1 upregulated SSRP1 expression by catalyzing H3K4 methylation and down-regulation of SSRP1 reversed the effect of SIRT1 on EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells. CONCLUSION: Exosomes loaded with circPARD3 promoted EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells through the miR-579-3p/SIRT1/SSRP1 axis. Graphical Headlights • EBV-miR-BART4 induces the stemness and resistance of NPC-SP cells. • CircPARD3 regulates SIRT1 by miR-579-3p. • SIRT1 regulates SSRP1 expression by histone methylation. • Exosomes loaded with circPARD3 promotes EBV-miR-BART4-induced NPC-SP cell stemness and resistance by the miR-579-3p/SIRT1/SSRP1 axis.

Bioinformatics analysis of markers based on m6 A related to prognosis combined with immune invasion of renal clear cell carcinoma.

The incidence rate of renal cell carcinoma (RCC) is about 3% of all adult cancers. Of these, the Kidney clear cell renal cell carcinoma (KIRC) is the most common type, accounting for about 70%-75% of RCC. KIRC is difficult to be detected in time clinically. KIRC still has no effective treatment at this stage. We combined high-throughput bioinformatics analysis to obtained the structural sequence transcriptome data, relevant clinical information, and m6 A gene map of KIRC patients from genomics TCGA database. Pearson's correlation analysis was used to explore m6 A related gene long noncoding RNAs (lncRNAs), and then univariate Cox regression analysis was performed to screen the prognostic role of KIRC patients. Lasso-Cox regression was performed to establish the lncRNAs risk model associated with m6 A.LINC02154 and AC016773.2, Z98200.2, AL161782.1, EMX2OS, AC021483.2, CD27-AS1, AC006213.3 were iidentif. Compared with the low-risk group, the overall survival of patients in the high-risk group was significantly worse. Analyzing whether there are differences in immune cells between high-risk and low-risk subgroups. There were CD4 memory resting, Monocytes, Macrophages M1, Dendritic cells activated, Mast cells resting, which had higher infiltrations in the low-risk group. We performed Go enrichment analysis, Kyoto Encyclopedia of Genes and Genomes enrichment analysis and gene set enrichment analysis enrichment analysis. Overall, our results suggest that the component of m6A-related lncRNAs in the prognostic signal may be a key mediator in the immune microenvironment of KIRC, which represents a promising therapeutic effect.

Double-Sided Sapphire Optrodes with Conductive Shielding Layers to Reduce Optogenetic Stimulation Artifacts.

Optrodes, which are single shaft neural probes integrated with microelectrodes and optical light sources, offer a remarkable opportunity to simultaneously record and modulate neural activities using light within an animal's brain; however, a common problem with optrodes is that stimulation artifacts can be observed in the neural recordings of microelectrodes when the light source on the optrode is activated. These stimulation artifacts are undesirable contaminants, and they cause interpretation complexity when analyzing the recorded neural activities. In this paper, we tried to mitigate the effects of the stimulation artifacts by developing a low-noise, double-sided optrode integrated with multiple Electromagnetic Shielding (EMS) layers. The LED and microelectrodes were constructed separately on the top epitaxial and bottom substrate layers, and EMS layers were used to separate the microelectrodes and LED to reduce signal cross-talks. Compared with conventional single-sided designs, in which the LED and microelectrodes are constructed on the same side, our results indicate that double-sided optrodes can significantly reduce the presence of stimulation artifacts. In addition, the presence of stimulation artifacts can further be reduced by decreasing the voltage difference and increasing the rise/fall time of the driving LED pulsed voltage. With all these strategies, the presence of stimulation artifacts was significantly reduced by ~76%. As well as stimulation suppression, the sapphire substrate also provided strong mechanical stiffness and support to the optrodes, as well as improved electronic stability, thus making the double-sided sapphire optrodes highly suitable for optogenetic neuroscience research on animal models.

Increased miR-124-3p alleviates type 2 inflammatory response in allergic rhinitis via IL-4Rα.

BACKGROUND AND OBJECTIVES: miRNAs play a crucial role in regulating immune responses. However, the effect of miR-124-3p on type 2 inflammation in allergic rhinitis (AR) is unclear. We aimed to study the immune regulation of miR-124-3p in AR and the mechanisms involved. METHODS: The direct interaction between miR-124-3p and IL-4Rα was confirmed through a dual-luciferase reporter assay. In vitro splenic lymphocytes from mice and peripheral blood mononuclear cells (PBMCs) from healthy individuals were cultured and treated with miR-124-3p mimic/inhibitor. Twenty-four female C57BL/C mice were divided into four groups: control, AR model, miR-124-3p agomir, and miR-124-3p antagomir groups (n = 6 per group). The allergic responses were evaluated based on the number of sneezing and nasal scratching, the serum HDM-specific IgE (sIgE) levels, and the degree of nasal mucosa eosinophil infiltration. The expression of IL-4Rα, p-STAT6, and type 2 inflammatory cytokines (IL-4, IL-5 and IL-13) in lymphocytes or nasal mucosa was determined by qPCR, western blotting, flow cytometry, immunohistochemistry and immunofluorescence. RESULTS: miR-124-3p directly targets the 3'UTR of IL-4Rα. The miR-124-3p mimic lowered the IL-4Rα, p-STAT6, IL-4, IL-5, and IL-13 expression levels in both mouse splenic lymphocytes and human PBMCs in vitro, and the miR-124-3p inhibitor rescued these changes. Furthermore, the miR-124-3p agomir decreased the levels of IL-4Rα and IL-4 in nasal mucosa, Th2 differentiation in spleen, and allergic response in AR mice. Moreover, the miR-124-3p antagonist increased the IL-4Rα and IL-4 levels and further aggravated the allergic responses. CONCLUSIONS: miR-124-3p might attenuate type 2 inflammation in AR by regulating IL-4Rα signaling, and miR-124-3p may be a promising new target in AR treatment.

120 GHz Frequency-Doubler Module Based on GaN Schottky Barrier Diode.

Traditional GaAs-based frequency multipliers still exhibit great challenges to meet the demand for solid-state high-power THz sources due to low breakdown voltage and heat dissipation of the Schottky barrier diode (SBD). In this study, a GaN SBD chain was fabricated with n-/n+-GaN structure. As a consequence, the breakdown voltage of 54.9 V at 1 µA and cut-off frequency of 587.5 GHz at zero bias were obtained. A 120 GHz frequency-doubler module based on the GaN SBD chain was designed and fabricated. When driven with 500 mW input power in a continuous wave, the output power of the frequency-doubler module was 15.1 mW at 120 GHz. Moreover, the experiments show that the frequency-doubler module can endure an input power of 2 W. In addition, it is worth noting that the SBD chain works well at an anode temperature of 337.2 °C.

Atlas of currently available human neutralizing antibodies against SARS-CoV-2 and escape by Omicron sub-variants BA.1/BA.1.1/BA.2/BA.3.

SARS-CoV-2 Omicron variant has presented significant challenges to current antibodies and vaccines. Herein, we systematically compared the efficacy of 50 human monoclonal antibodies (mAbs), covering the seven identified epitope classes of the SARS-CoV-2 RBD, against Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3. Binding and pseudovirus-based neutralizing assays revealed that 37 of the 50 mAbs lost neutralizing activities, whereas the others displayed variably decreased activities against the four Omicron sub-variants. BA.2 was found to be more sensitive to RBD-5 antibodies than the other sub-variants. Furthermore, a quaternary complex structure of BA.1 RBD with three mAbs showing different neutralizing potencies against Omicron provided a basis for understanding the immune evasion of Omicron sub-variants and revealed the lack of G446S mutation accounting for the sensitivity of BA.2 to RBD-5 mAbs. Our results may guide the application of the available mAbs and facilitate the development of universal therapeutic antibodies and vaccines against COVID-19.

Effects of radiofrequency blanching on lipoxygenase inactivation, physicochemical properties of sweet corn (Zea mays L.), and its correlation with cell morphology.

This study investigated the effects of radiofrequency (RF) and boiling-water (BW) blanching on lipoxygenase (LOX) activity, physicochemical properties, and changes in the cellular morphology of sweet corn kernels. First, a speed-adjustable device was introduced to rotate the sample for improving heating uniformity. Then, the maximum RF heating rate and uniform temperature distribution of samples were obtained under 160 mm electrode gap, 120 g sample weight, and 14 r/min rotating speed. With increased RF heating temperature ranging from 50 °C to 80 °C, the residual activity of LOX significantly decreased to 4.68%. Samples blanched by RF treatment maintained better color, texture, and nutrient content than those by BW when similar levels of enzyme inactivation were achieved. Micrographs also showed the cells were increasingly damaged with increased RF heating temperature, whereas the cells were damaged much more severely when treated with BW. Besides, microscopic destruction of cells also explains the changes in physicochemical properties.

Long-Term Exposure to Sulfur Dioxide Before Sensitization Decreased the Production of Specific IgE in HDM-Sensitized Allergic Rhinitis Mice.

Background: Exposure to atmospheric pollutants is closely associated with the occurrence of allergic rhinitis (AR). However, the role of sulfur dioxide (SO2) in promoting allergic inflammation in AR is poorly understood. Our study aims to investigate the effect of SO2 on allergic inflammation in house dust mite (HDM)-sensitized mice. Methods: Thirty mice were randomly divided into five groups: the control, AR model, AR model exposed to SO2, AR model with long-term SO2 exposure, and SO2-treated control groups. Nasal symptom score was recorded. The serum HDM specific IgE (sIgE) was measured by enzyme-linked immunosorbent assay. Expression of Th1/Th2/Th17 cytokines in nasal mucosa was detected by immunohistochemistry and quantitative PCR. Expression of a low-affinity sIgE receptor (CD23) on B lymphocytes in nasal mucosa was assessed by immunofluorescence. Results: SO2 increased not only nasal symptom score but also the number of infiltrating eosinophils and expression of Th1/Th2/Th17 cytokines in nasal mucosa of HDM-sensitized AR mice. Furthermore, SO2 increased the serum sIgE level in AR mice. However, long-term SO2 exposure decreased the serum sIgE level in AR mice. Moreover, long-term SO2 exposure decreased CD23+ B lymphocytes in the nasal mucosa. Conclusion: SO2 exposure aggravated nasal symptom, serum sIgE level, eosinophil infiltration, and Th1/Th2/Th17 inflammation in AR mice. However, the serum sIgE level could be lowered by long-term SO2 exposure. This inhibitory effect of SO2 on IgE production may be suppressed by CD23+ B lymphocytes.