Rose Bengal Photodynamic Therapy (RB-PDT) Modulates the Inflammatory Response in LPS-Stimulated Human Corneal Fibroblasts By Influencing NF-κB and p38 MAPK Signaling Pathways

PURPOSE

To investigate the effect of rose bengal photodynamic therapy on lipopolysaccharide-induced inflammation in human corneal fibroblasts. Furthermore, to analyze potential involvement of the mitogen-activated protein kinase and nuclear factor kappa B signaling pathways in this process.

METHODS

Human corneal fibroblast cultures underwent 0-2.0 µg/mL lipopolysaccharide treatment, and 24 h later rose bengal photodynamic therapy (0.001% RB, 565 nm wavelength illumination, 0.17 J/cm2 fluence). Interleukin-6, interleukin-8, intercellular adhesion molecule-1, interferon regulatory factor-3, interferon α2, and interferon β1 gene expressions were determined by quantitative PCR. Interleukin-6, interleukin-8, and C-C motif chemokine ligand-4 concentrations in the cell culture supernatant were measured by enzyme-linked immunosorbent assays and intercellular adhesion molecule-1 protein level in human corneal fibroblasts by western blot. In addition, the nuclear factor kappa B and mitogen-activated protein kinase signaling pathways were investigated by quantitative PCR and phosphorylation of nuclear factor kappa B p65 and p38 mitogen-activated protein kinase by western blot.

RESULTS

Rose bengal photodynamic therapy in 2.0 µg/mL lipopolysaccharide-stimulated human corneal fibroblasts triggered interleukin-6 and interleukin-8 mRNA (p < .0001) and interleukin-6 protein increase (p < .0001), and downregulated intercellular adhesion molecule-1 expression (p < .001). C-C motif chemokine ligand-4, interferon regulatory factor-3, interferon α2, and interferon β1 expressions remained unchanged (p ≥ .2). Rose bengal photodynamic therapy increased IκB kinase subunit beta, nuclear factor kappa B p65, extracellular signal-regulated kinases-2, c-Jun amino terminal kinase, and p38 transcription (p ≤ .01), and triggered nuclear factor kappa B p65 and p38 mitogen-activated protein kinase phosphorylation (p ≤ .04) in lipopolysaccharide treated human corneal fibroblasts.

CONCLUSION

Rose bengal photodynamic therapy of lipopolysaccharide-stimulated human corneal fibroblasts can modify the inflammatory response by inducing interleukin-6 and interleukin-8 expression, and decreasing intercellular adhesion molecule-1 production. C-C motif chemokine ligand-4, interferon regulatory factor-3, and interferon α and β expressions are not affected by rose bengal photodynamic therapy in these cells. The underlying mechanisms may be associated with nuclear factor kappa B and p38 mitogen-activated protein kinase pathway activation.

In Situ Exfoliation Growth Strategy Realizing Controlled Synthesis of 3D to 2D MOF Materials as High-Performance Electrochemical Biosensors

Two-dimensional (2D) metal-organic framework (MOF) nanosheets with large surface area, ultrathin thickness, and highly accessible active sites have attracted great research attention. Developing efficient approaches to realize the controllable synthesis of well-defined 2D MOFs with a specific composition and morphology is critical. However, it is still a significant challenge to construct thin and uniform 2D MOF nanosheets and resolve the reagglomeration as well as poor stability of target 2D MOF products. Here, an "in situ exfoliation growth" strategy is proposed, where a one-step synthetic process can realize the successful fabrication of PBA/MIL-53(NiFe)/NF nanosheets on the surface of nickel foam (NF) via in situ conversion and exfoliation growth strategies. The PBA/MIL-53(NiFe)/NF nanosheets combine the individual advantages of MOFs, Prussian blue analogues (PBAs), and 2D materials. As expected, the resulting PBA/MIL-53(NiFe)/NF as a glucose electrode exhibits an extremely high sensitivity of 25.74 mA mM-1 cm-2 in a very wide concentration range of 180 nM to 4.8 μM. The present exciting work provides a simple and effective strategy for the construction of high-performance nonenzymatic glucose electrochemical biosensors.

Plastic film mulching application improves potato yields, reduces ammonia emissions, but boosts the greenhouse gas emissions in China

With global population growth and climate change, food security and global warming have emerged as two major challenges to agricultural development. Plastic film mulching (PM) has long been used to improve yields in rain-fed agricultural systems, but few studies have focused on soil gas emissions from mulched rainfed potatoes on a long-term and regional scale. This study integrated field data with the Denitrification-Decomposition (DNDC) model to evaluate the impacts of PM on potato yields, greenhouse gas (GHG) and ammonia (NH3) emissions in rainfed agricultural systems in China. We found that PM increased potato yield by 39.7 % (1505 kg ha-1), carbon dioxide (CO2) emissions by 15.4 % (123 kg CO2 eq ha-1), nitrous oxide (N2O) emissions by 47.8 % (1016 kg CO2 eq ha-1), and global warming potential (GWP) by 38.9 % (1030 kg CO2 eq ha-1), while NH3 volatilization decreased by 33.9 % (8.4 kg NH3 ha-1), and methane (CH4) emissions were little changed compared to CK. Specifically, the yield after PM significantly increased in South China (SC), North China (NC), and Northwest China (NWC), with increases of 66.1 % (2429 kg ha-1), 44.1 % (1173 kg ha-1), and 43.6 % (956 kg ha-1) compared to CK, respectively. The increase in GWP and greenhouse gas emission intensity (GHGI) under PM was more pronounced in the Northeast China (NEC) and NWC regions, with respective increases of 57.1 % and 60.2 % in GWP, 16.9 % and 10.3 % in GHGI. While in the Middle and Lower reaches of the Yangtze River (MLYR) and SC, PM decreased GHGI with 10.2 % and 31.1 %, respectively. PM significantly reduced NH3 emissions in all regions and these reductions were most significant in Southwest China (SWC), SCand MLYR, which were 41 %, 38.0 %, and 38.0 % lower than CK, respectively. In addition, climatic and edaphic variables were the main contributors to GHG and NH3 emissions. In conclusion, it is appropriate to promote the use of PM in the MLYR and SC regions, because of the ability to increase yields while reducing environmental impacts (lower GHGI and NH3 emissions). The findings provide a theoretical basis for sustainable agricultural production of PM potatoes.

Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-β and IL-6 Expression of Human Corneal Fibroblasts, In Vitro

PURPOSE

To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor β1 (TGF-β1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT).

METHODS

HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-β1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA.

RESULTS

TGF-β1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-β1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-β1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups.

CONCLUSIONS

Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-β1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-β1 and IL-6 protein level after 24 h.

Exploring low-carbon mulching strategies for maize and wheat on-farm: Spatial responses, factors and mitigation potential

Mulching strategies - including plastic film mulching (FM) and straw mulching (SM) - can enhance crop yields while affecting multiple greenhouse gas (GHG) fluxes. However, most of currently published site-based studies only focus on a certain gas, resulting in an inability to spatially integrated understanding of changes in agricultural global warming potential (GWP) and greenhouse gas intensity (GHGI) caused by mulching across China. Thus, we developed an optimal model considering crop type, meteorology, soil and management variables by four machine learning methods, namely support vector machine, multilayer perceptron, random forest, and gradient boosting machine (GBM). Then we mapped the relative changes in yield and GHG fluxes caused by mulching strategies. The GBM model had the best simulation capability for yield and GHGs in China. Our result showed that FM increased yield in maize (25 %) and wheat (19 %), while SM respectively increased by 14 % and 11 %. Among the relative changes due to mulching strategies, yield and N2O emissions were mainly influenced by soil fertility and soil properties, CH4 uptakes and CO2 emissions were more affected by environmental factors. GWP in maize and wheat average increased by 40 % under FM, while SM decreased GWP by 14 % and 2 %, respectively. Besides, FM average increased GHGI in maize and wheat by 17 % and 9 %, and SM decreased GHGI by 22 % and 12 %, respectively. Spatially, FM reduced maize GWP on 19 % of cropland, while SM reduced maize and wheat GWP on 71 % and 64 % of cropland, respectively. Soil pH was significantly correlated with ΔGHGI in maize and wheat. Our analysis not only estimated for the first time the spatial effects of mulching strategies across China, but also systematically analyzes the agricultural carbon emission mitigation potential of mulching strategies, which promote the development of low-carbon agriculture based on locally appropriate mulching strategies.

Human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium

PURPOSE

To investigate human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium (CM).

METHODS

A human corneal epithelial cell line (HCE-T), human corneal fibroblasts (HCF) and keratoconus fibroblasts (KC-HCF) have been used. Twenty-four hours after RB-PDT (0.001% RB concentration, 565 nm wavelength illumination, 0.17 J/cm2 fluence) cell migration rate using scratch assay and growth factor concentrations in the cell culture supernatant using ELISA have been determined. In addition, the effect of CM has been observed.

RESULTS

RB-PDT significantly reduced migration rate in all cell types, compared to controls (p≤0.02). Migration rate of HCE-T cultures without RB-PDT (untreated) was significantly higher using HCF CM after RB-PDT, than using HCF CM without RB-PDT (p<0.01). Similarly, untreated HCF displayed a significantly increased migration rate with HCE-T CM after RB-PDT, compared to HCE-T CM without treatment (p<0.01). Furthermore, illumination alone and RB-PDT significantly decreased keratinocyte growth factor (KGF) concentration in HCF and KC-HCF supernatant, and RB-PDT significantly decreased soluble N-Cadherin (SN-Cad) concentration in HCF supernatant, compared to controls (p<0.01 for all). In HCE-T CM, RB-PDT increased hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGFb) concentration (p≤0.02), while decreasing transforming growth factor β (TGF-β) concentration (p<0.01). FGFb concentration increased (p<0.0001) and TGF-β concentration decreased (p<0.0001) in HCF CM, by RB-PDT. Epidermal growth factor (EGF), HGF, and TGF-β concentration decreased (p≤0.03) and FGFb concentration increased (p<0.01) in KC-HCF CM, using RB-PDT.

CONCLUSIONS

HCE-T, HCF and KC-HCF migration rate is reduced 24 hours after RB-PDT. In contrast, HCE-T migration is enhanced using HCF CM after RB-PDT, and HCF migration rate is increased through HCE-T CM following RB-PDT. Modulation of EGF, KGF, HGF, FGFb, TGF-β and N-Cadherin secretion through RB-PDT may play an important role in corneal wound healing.

(FeMnCe)-co-doped MOF-74 with significantly improved performance for overall water splitting

Developing inexpensive electrocatalysts with high activity and stability is of great value for overall water splitting. In this work, we designed a series of 3d-4f (FeMnCe)-trimetallic MOF-74 with different ratios of 3d- and 4f-metal centers. Among them, FeMn6Ce0.5-MOF-74/NF exhibited the best electrocatalytic performance for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline solution. It only requires a low overpotential of 281 mV@100 mA cm-2 for OER and 186 mV@-10 mA cm-2 for HER in 1 M KOH. With FeMn6Ce0.5-MOF-74/NF as the anode and cathode in the overall water splitting system, only 1.65 V is needed to deliver a current density of 10 mA cm-2. In particular, for the as-fabricated FeMn6Ce0.5-MOF-74/NF||Pt/C cell unit, only 1.40 V is needed to achieve 10 mA cm-2. Therefore, the successful design of 3d-4f mixed-metallic MOF-74 provides a new viewpoint to develop highly efficient non-precious metal electrocatalysts.

One-step synthesis of 2D@3D hollow Prussian blue analogue as a high-performance bifunctional electrochemical sensor

Prussian blue analogues (PBAs) are a family of classic coordination polymers. They have been widely applied in various fields including electrochemical sensors. Cubic nanoparticle structure is their common morphology. It is still a great challenge to design a hollow and two-dimensional (2D) PBA material. Of course, it will be a significant surprise if a hollow cube and 2D sheet can be integrated into one material. In this work, we designed a simple one-step synthetic strategy and resolved the above difficulty, wherein a hollow cubic PBA covered by 2D ultrathin nanosheets was successfully constructed, namely hollow tremella-like PBA (HTPBA). Furthermore, Ni foam (NF) as a substrate was introduced to obtain a self-supporting HTPBA/NF-12 electrode. HTPBA/NF-12, as a bifunctional electrochemical sensor electrode, exhibited distinguished catalytic performance towards glucose and nitrite, including remarkable selectivity, reproducibility, sensitivity for glucose (21 410 μA mM^-1 cm^-2) and nitrite (1248 μA mM^-1 cm^-2), wide linear range of 2-1250 μM and 5-3380 μM, along with low detection limit of 0.056 μM and 0.38 μM, respectively. More importantly, HTPBA/NF-12 electrodes possessed good reusability and practicability even in goat serum. In this study, we developed a simple and effective strategy to fabricate 2D@3D PBA material with excellent electrocatalytic activity and provide a totally new viewpoint in the PBA sensing field.

UiO-66-Derived PBA Composite as Multifunctional Electrochemical Non-Enzymatic Sensor Realizing High-Performance Detection of Hydrogen Peroxide and Glucose

In this work, a highly efficient multifunctional non-enzymatic electrochemical sensor is successfully fabricated based on a facile two-step synthetic strategy. It resolves two important challenges of poor stability and low reproducibility compared to conventional electrochemical enzyme-based sensors. Herein, a metal-organic framework (UiO-66) is selected as a sacrificial template to construct the corresponding Prussian blue analogue (PBA) target to improve its stability and conductivity, namely, PBA/UiO-66/NF. Target PBA/UiO-66/NF exhibits excellent electrochemical sensing performance as hydrogen peroxide (H₂O₂) and glucose sensors with ultrahigh sensitivity of up to 1903 μA mM^-1 cm^-2 for H₂O₂ and 22,800 μA mM^-1 cm^-2 for glucose, as well as a very low detection limit of 0.02 μM (S/N = 3) for H₂O₂ and 0.28 μM for glucose. Especially, extremely high stability can be observed, which will be beneficial for practical application.

CoOx nanoparticles loaded on carbon spheres with synergistic effects for effective inhibition of shuttle effect in Li-S batteries

Lithium-sulfur (Li-S) batteries, as one of the new energy storage batteries, show immense potential due to their high theoretical specific capacity and theoretical energy density. However, there are still some problems to be solved, among which the shuttle effect of lithium polysulfides is one extremely serious issue with respect to the industrial application of Li-S batteries. Rational design of electrode materials with effective catalytic conversion ability is an effective route to accelerate the conversion of lithium polysulfides (LiPSs). Herein, considering the adsorption and catalysis of LiPSs, CoO_x nanoparticles (NPs) loaded on carbon sphere composites (CoO_x/CS) were designed and constructed as cathode materials. The CoO_x NPs obtained, with ultralow weight ratio and uniform distribution, consist of CoO, Co₃O₄, and metallic Co. The polar CoO and Co₃O₄ enable chemical adsorption towards LiPSs through Co-S coordination, and the conductive metallic Co can improve electronic conductivity and reduce impedance, which is beneficial for ion diffusion at the cathode. Based on these synergistic effects, the CoO_x/CS electrode exhibits accelerated redox kinetics and enhanced catalytic activity for conversion of LiPSs. Consequently, the CoO_x/CS cathode delivers improved cycling performance, with an initial capacity of 980.8 mA h g^-1 at 0.1C and a reversible specific capacity of 408.4 mA h g^-1 after 200 cycles, along with enhanced rate performance. This work provides a facile route to construct cobalt-based catalytic electrodes for Li-S batteries, and promotes understanding of the LiPSs conversion mechanism.

Untersuchung der Bengalrosa photodynamischen Therapie auf die Viabilität und Proliferation humaner keratolimbaler Epithel- und Stromazellen, in vitro

ZUSAMMENFASSUNG Ziel: Die photodynamische Therapie kann eine alternative Behandlungsmethode bei antibiotikaresistenten Keratitiden darstellen. In dieser Studie wurde die Wirkung der photodynamischen Therapie mit Bengalrosa (RB-PDT) auf die Viabilität und Proliferation von humanen limbalen Epithelstammzellen (T-LSCs), humanen Hornhautepithelzellen (HCE-T), limbalen Fibroblasten (LFCs), normalen und Keratokonus-Fibroblasten (HCFs und KC-HCFs) „in vitro“ untersucht. Material und Methoden: Für die Experimente an den limbalen Epithelstammzellen wurden 2 verschiedene Zelllinien (T-LSCs und HCE-T) verwendet. Die primären LFCs und HCFs wurden aus den Korneoskleralringen von Hornhautspendern, die KC-HCFs aus perforierenden Keratoplastiken von Keratokonus-Patienten isoliert und kultiviert (jeweils n=5). Die RB-PDT wurde mit einer 0,001% igen RB-Konzentration bei einer Wellenlänge von 565 nm und einer Energiedosis von 0,14 bis 0,7 J/cm2 durchgeführt. Zur Bestimmung der Viabilität wurde 24 Stunden nach der Bestrahlung der XTT-, zur Bestimmung der Proliferation der BrdU-Assay verwendet. Ergebnisse: Die ausschließliche Verwendung von RB oder Bestrahlung hatten keinen messbaren Einfluss auf die Viabilität oder Proliferation der unterschiedlichen Zelltypen (p≥0,1). Unter Verwendung der RB-PDT mit einer Dosis von 0,17 J/cm2 sank die Viabilität jedoch in den HCFs (p < 0,001) und KC-HCFs (p < 0,0001), und bei einer Dosis von 0,35 J/cm2 in den T-LSCs (p < 0,001), HCE -T (p < 0,05) und LFCs (p < 0,0001). Die Zellproliferation verringerte sich signifikant ab einer Dosis von 0,14 J/cm2 in T-LSCs (p < 0,0001), HCE-T (p < 0,05) und KC- HCFs (p < 0,001) und ab einer Dosis von 0,17 J/cm2 Fluenz in HCFs (p < 0,05). Für die Proliferationsbestimmung der LFCs konnten mit dem BrdU-Assay keine Werte ermittelt werden. Schlussfolgerung: Die RB-PDT zeigt eine dosisabhängige Phototoxizität auf Hornhautepithel- und Stromazellen. Die in dieser Studie ermittelten Daten und experimentellen Parameter bieten eine verlässliche Referenz für zukünftige Untersuchungen für die photodynamische Therapie mit Bengalrosa. Abstract Purpose: To investigate the effect of Rose Bengal photodynamic therapy (RB-PDT) on viability and proliferation of human limbal epithelial stem cells (T-LSCs), human corneal epithelial cells (HCE-T), human limbal fibroblasts (LFCs), human normal and keratoconus fibroblasts (HCFs and KC-HCFs), in vitro. Methods: T-LSCs and HCE-T cell lines were used in this research. LFCs were isolated from healthy donor corneal limbus (n=5), HCFs from healthy human donor corneas (n=5), and KC-HCFs from penetrating keratoplasties of keratoconus patients (n=5). After cell culture, RB-PDT was performed using 0.001% RB concentration and 565 nm wavelength illumination, with 0.14 to 0.7 J/cm2 fluence. The XTT and the BrdU assays were used to assess cell viability and proliferation, 24 hours after RB-PDT. Results: Rose Bengal or illumination alone did not change cell viability or proliferation in any of the cell types (p≥0.1). However, following RB-PDT, viability decreased significantly from 0.17 J/cm2 fluence in HCFs (p<0.001) and KC-HCFs (p<0.0001), from 0.35 J/cm2 fluence in T-LSCs (p<0.001), HCE-T (p<0.05) and LFCs ((p<0.0001), respectively. Cell proliferation decreased significantly from 0.14 J/cm2 fluence in T-LSCs (p<0.0001), HCE-T (p<0.05), and KC-HCFs (p<0.001) and from 0.17 J/cm2 fluence in HCFs (p<0.05). Regarding LFCs proliferation, no values could be determined by the BrdU assay. Conclusions: Though RB-PDT seems to be a safe and effective treatment method in vivo, its dose-dependent phototoxicity on corneal epithelial and stromal cells has to be respected. The data and the experimental parameters applied in this study may provide a reliable reference for future investigations.

In Vitro Expression Analysis of Cytokines and ROS-Related Genes in Human Corneal Fibroblasts and Keratocytes of Healthy and Keratoconus Corneas

PURPOSE

To investigate expression of cytokines and ROS-related genes in stromal cells of healthy and keratoconus (KC) corneas.

METHODS

Expression analysis was performed for cytokines including several interleukins (IL), Tumor necrosis factor-α (TNF-α), Transforming growth factor-β1 (TGF-β1), Interferon-γ (IFN-γ) and ROS-related genes such as Catalase, Glutathione peroxidase 1, NADPH oxidase 1, superoxide dismutase 1 in corneal fibroblasts (HCFs/KC-HCFs) or keratocytes (Keratocytes/KC-Keratocytes) by qPCR and ELISA.

RESULTS

Gene and protein expression of most inflammatory markers was decreased in keratocytes compared to fibroblasts, whereas no differences were found between healthy and keratoconus cells for the majority of cytokines measured. TNF-α expression was increased at gene (KC keratocytes) and protein levels (supernatant of Keratocytes/KC-Keratocytes) compared to corneal fibroblasts. No differential expression of ROS-related genes was detected between healthy and diseased cells in both fibroblasts and keratocytes.

CONCLUSION

Increased expression of several inflammatory markers described as altered in KC was not evident in KC cells in vitro.

Efficacy of Off-Label Anti-Amoebic Agents to Suppress Trophozoite Formation of Acanthamoeba spp. on Non-Nutrient Agar Escherichia Coli Plates

Acanthamoeba keratitis (AK) is a dangerous infectious disease, which is associated with a high risk of blindness for the infected patient, and for which no standard therapy exists thus far. Patients suffering from AK are thus treated, out of necessity, with an off-label therapy, using drugs designed and indicated for other diseases/purposes. Here, we tested the capability of the off-label anti-amoebic drugs chlorhexidine (CH; 0.1%), dibromopropamidine diisethionate (DD; 0.1%), hexamidine diisethionate (HD; 0.1%), miltefosine (MF; 0.0065%), natamycin (NM; 5%), polyhexamethylene biguanide (PHMB; 0.02%), povidone iodine (PVPI; 1%), and propamidine isethionate (PD; 0.1%) to suppress trophozoite formation of Acantamoeba castellanii and Acanthamoeba hatchetti cysts on non-nutrient agar Escherichia coli plates. Of the eight off-label anti-amoebic drugs tested, only PVPI allowed for a complete suppression of trophozoite formation by drug-challenged cysts for all four Acanthamoeba isolates in all five biological replicates. Drugs such as NM, PD, and PHMB repeatedly suppressed trophozoite formation with some, but not all, tested Acanthamoeba isolates, while other drugs such as CH, DD, and MF failed to exert a relevant effect on the excystation capacities of the tested Acanthamoeba isolates in most, if not all, of our repetitions. Our findings suggest that pre-testing of the AK isolate with the non-nutrient agar E. coli plate assay against the anti-amoebic drug intended for treatment should be performed to confirm that the selected drug is cysticidal for the Acanthamoeba isolate.

Ultraprecision machining and on-machine measurement of the radial Fresnel lens structure array of a large-scale roller mold

Automation and on-machine manufacturing process measurement is essential in increasing product productivity. However, a significant challenge is the radial Fresnel lens structure-array machining and on-machine measurement research for a large-scale roller mold. We present a rotating A-axis machining method for manufacturing an array of a radial Fresnel lens structure, based on an ultraprecision four-axis drum roll lathe system developed by the team. Therefore, based on the principle of a virtual multiprobe, the traditional two-point method is improved and applied to the on-machine measurement of the radial Fresnel lens structure of the roll mold. Through the machining and on-machine measurement experiments of the radial Fresnel lens structure of the roller mold, the feasibility of the machining method and measurement method is verified.

Optimum fertilizer application rate to ensure yield and decrease greenhouse gas emissions in rain-fed agriculture system of the Loess Plateau

Application of nitrogen (N) can increase the supply of N in soil and, in turn, can lead to higher yield-but also to large increase in emissions of greenhouse gases (GHGs) if applied in excess. To determine the optimum dose of N for maize planting system, we analysed the relationship between yield and emissions of GHGs at seven levels of N, namely 50, 100, 150, 200, 250, 300, and 350 kg ha^-1, using the DNDC (denitrification decomposition) model and maize grown with and without mulching. The model simulated the following variables: maize production; emissions of carbon dioxide (CO₂), nitrous oxide (N₂O), and methane (CH₄); global warming potential (GWP); and GHG intensity (GHGI). We used data from 1980 to 2013 for a rain-fed region of the Loess Plateau in north-western China and validated the DNDC model against data from field experiments. The model performed well in simulating yield and GHG emissions (Adj.R² > 0.61). Under mulching, the average yield of maize was 3.6-12.2 t ha^-1 and the partial factor productivity was 73.1-35.0 kg kg^-1; and both of these were significantly higher 78%-236% than those in the crop without mulching. The emissions of CO₂, N₂O, and the GWP increased with the increase in the dose of N whereas CH₄ emissions remained unaffected by the dose. Mulching increased yields significantly in the north-western region, and the GWP and GHGI were higher mainly in the central and north-western regions. The optimum dose of N for maize grown with mulching ranged between 150 kg ha^-1 and 200 kg ha^-1 and offers the best balance between higher yield and lower emissions. The optimum dose may promote the development of mulched maize and provide a reference standard for dryland agriculture in zones with similar climates elsewhere in the world.

Population management in an urban center using the dynamic integrated solution for an adequate atmospheric environmental quality

Accelerated growth in urban populations has become a powerful force for human development, particularly in developed countries. Metropolitan cities are centers for technical and economic advancement, but air pollution, overflowing of water, and other climate effects still pose significant problems related to nature, climate, and the environment. Cities are vulnerable to increasingly dense, diverse, and interdependent urban systems. A single extreme occurrence can contribute to a systemic break-up of a city's infrastructure, often like dominoes. In this paper, a dynamic integration-assisted population management solution (DI-PMS) has been proposed. DI-PMS recognizes that the latest facilities' optimal usage of knowledge and technologies is needed to increase urbanization. They are one of the critical priorities of the weather community. Such integrated urban weather, environmental, and climate services will help cities address dangers including storms, floods, heatwaves, and air pollution, especially in climate change. The goal is to create urban facilities that satisfy communities' unique needs by high-resolution forecasting and pollution reduction climate services, which allow the construction of durable, robust, and thriving cities that support the Sustainable Development Goals. Several recent international surveys to explore these topics have been undertaken. DI-PMS gives a brief description of urban hydrometeorological, climate and air pollution activities, outlines the new urban integrated weather and environmental services concept, and emphasizes the need for science to be implemented.

A self-balancing circuit centered on MoOsm1 kinase governs adaptive responses to host-derived ROS in Magnaporthe oryzae

The production of reactive oxygen species (ROS) is a ubiquitous defense response in plants. Adapted pathogens evolved mechanisms to counteract the deleterious effects of host-derived ROS and promote infection. How plant pathogens regulate this elaborate response against ROS burst remains unclear. Using the rice blast fungus Magnaporthe oryzae, we uncovered a self-balancing circuit controlling response to ROS in planta and virulence. During infection, ROS induces phosphorylation of the high osmolarity glycerol pathway kinase MoOsm1 and its nuclear translocation. There, MoOsm1 phosphorylates transcription factor MoAtf1 and dissociates MoAtf1-MoTup1 complex. This releases MoTup1-mediated transcriptional repression on oxidoreduction-pathway genes and activates the transcription of MoPtp1/2 protein phosphatases. In turn, MoPtp1/2 dephosphorylate MoOsm1, restoring the circuit to its initial state. Balanced interactions among proteins centered on MoOsm1 provide a means to counter host-derived ROS. Our findings thereby reveal new insights into how M. oryzae utilizes a phosphor-regulatory circuitry to face plant immunity during infection.

Applying multiple approaches to deepen understanding of mixing and mass transfer in large-scale aerobic fermentations

Different methods are used at Corteva^® Agriscience to improve our understanding of mixing in large-scale mechanically agitated fermentors. These include (a) use of classical empirical correlations, (b) use of small-scale models, and (c) computational fluid dynamics (CFD). Each of these approaches has its own inherent strengths and limitations. Classic empirical or semi-empirical correlations can provide insights into mass transfer, blending, shear, and other important factors but are dependent on the geometry and condition used to develop the correlations. Laboratory-scale modelling can be very useful to study mixing and model the effect of heterogeneity on the culture, but success is highly dependent on the methodology applied. CFD provides an effective means to accelerate the exploration of alternative design strategies through physics-based computer simulations that may not be adequately described by existing knowledge or correlations. However, considerable time and effort is needed to build and validate these models. In this paper, we review the various approaches used at Corteva Agriscience to deepen our understanding of mixing in large-scale fermentation processes.

Prophylactic fat-free diet in patients undergoing lobectomy for lung cancer does not decrease postoperative chylothorax: Results from a single-center retrospective study

PURPOSE

Reliable measures to prevent chylothorax following lobectomy are lacking. Herein a case-control study was conducted to investigate the effect of prophylactic fat-free diet on the incidence of chylothorax after thoracoscopic lobectomy and systemic lymph node dissection (SLND) for lung cancer.

METHODS

Between January 2015 and December 2017, the patients with primary non-small cell lung cancer who underwent lobectomy and SLND were retrospectively reviewed. Patients in the prophylactic group started fat-free diet one week before the surgery until removal of the chest tubes after the operation; while those in the control group took normal diet unless the onset of chylothorax. Logistic regression analysis was utilized to identify the predictive factors of chylothorax following lobectomy.

RESULTS

The data of 110 patients in the control group and 115 cases in the prophylactic group were collected. The patients in prophylactic group showed less intraoperative blood loss [(79.9±48.7) mL vs. (100.9±55.6) mL, p=0.003], reduced postoperative drainage volume [(504.3±268.0) mL vs. (714.1±618.5) mL, p=0.001], and shorter chest tube duration [(3.6±1.7) days vs. (4.2±2.6) days, p=0.014]; however, a similar incidence of chylothorax [3 (2.6%) vs. 7 (6.4%), p=0.207] was recorded. Multivariate logistic regression analysis indicated that neoadjuvant therapy was an independent positive factor of chylothorax (odd ratio [OR] = 9.257; 95% confidence interval [CI] 1.434-59.773, p=0.019); whereas high-volume experience of the surgeon was an independent negative factor of this complication (OR = 0.129; 95% CI 0.017-0.982, p=0.048).

CONCLUSION

Prophylactic fat-free diet does not decrease the incidence of chylothorax after lobectomy. Further well-designed trials are warranted to verify this occasional finding.

Single probe shear scanning method for on-machine measurement of an optical profile

This study presents a new (to the best of our knowledge) error separation method with a single displacement probe, named as single probe shear scanning (SPSS) method, for the on-machine optical profile measurement to overcome the problems of the existing multiprobe method like the large deviation of probe spacing and the probes' performance difference. The confocal sensor with superior dynamic range, high lateral resolution, and large measurement angle to surface is applied in this study to fulfill the measurement of the optical aspheric surface. The single probe measurement system, in which the probe fixed on a flexure hinge is driven straight within a millimeter-level travel range, is established to realize the function of the multiprobe. For the established system, a new exact profile reconstruction algorithm is built to eliminate the influences of straightness errors of the scanning stage and the systemic errors of shear stage, and to reduce the effect of the sensor drift. The reconstruction algorithms by difference measurement with two shears are studied to build the bidirectional segment stitching reconstruction method, which reduces the error accumulation and improves the reconstruction accuracy under the condition of measuring errors. A profile reconstruction method with three shears measurement is proposed to make a further improvement on the reconstruction accuracy. The proposed reconstruction method with three shears measurement is successfully employed for the on-machine measurement of an aspheric surface profile, and the evaluation results agree well with those from the Taylor profiler.

Edge/Defect-Rich, Metallic, and Oxygen-Heteroatom-Doped WS2 Superstructure with Superior Electrocatalytic Performance for Green Solar Energy Conversion

Two-dimensional tungsten sulfide is widely applied in electrocatalysis. However, WS₂ possesses catalytic active sites located at the layer edge and an inert surface for catalysis. Therefore, increasing the exposure of active sites at the edge and effectively activating the inert sites on the surface is an important challenge. Here, an edge/defect-rich and oxygen-heteroatom-doped WS₂ (ED-O-WS₂ ) superstructure was synthesized. The power-conversion efficiency (PCE) of dye-sensitized solar cells (DSCs) based on an ED-O-WS₂ counter electrode reached 10.36 % (under 1 sun, AM 1.5, 100 mW cm^-2 ) and 11.19 % (under 40 mW cm^-2 ). These values are, to our knowledge, the highest reported efficiency for DSCs based on Pt-free counter electrodes in I₃ ^- /I^- electrolytes. Analysis of the micro/nano structure and the electrocatalytic mechanism indicate that ED-O-WS₂ exhibits metallic properties in the electrolyte, and that abundant edges and defects as well as oxygen doping in ED-O-WS₂ play an important role in improving the catalytic activity of WS₂ . Moreover, ED-O-WS₂ displays better catalytic reversibility for I₃ ^- /I^- electrolytes than Pt.

Efficacy of triamcinolone-soaked polyglycolic acid sheet plus fully covered metal stent for preventing stricture formation after large esophageal endoscopic submucosal dissection

Esophageal stricture is a major problem for patients with large superficial esophageal squamous cell neoplasms (SESCNs) after endoscopic submucosal dissection (ESD). Although many measures could be used as prophylaxis for post-ESD strictures, a well-accepted method has not yet been established. We propose using a triamcinolone-soaked polyglycolic acid sheet plus fully covered metal stent (TS-PGA+FCMS) as a novel method to prevent stricture formation after large esophageal ESD. From June 2016 to May 2017, nine patients with SESCNs (≥3/4 of the esophageal circumference) who underwent TS-PGA+FCMS placement immediately after ESD and did not require additional surgical resection were enrolled in this case series. All stents were removed 4-6 weeks post-ESD. The sizes of mucosal defects in 9 patients were 3/4 (n = 1), 4/5 (n = 2), 1/1 (n = 6). The average size of resection was 90.0 mm (range: 60-140 mm). The incidence of stricture was 33.3% (3/9) of patients. No stricture occurred in 3 patients with noncircumferential resection, while stricture occurred in 50% (3/6) patients with circumferential resection. The median number of EBD sessions was 4 (range: 3-4 sessions). No adverse events or recurrences were observed during the median follow-up period of 15.2 months (range: 12-22 months). The TS-PGA+FCMS method is safe and may decrease the incidence of esophageal stricture and the number of EBD sessions after large esophageal ESD.

Synthesis, Crystal Structure, UV-Vis Adsorption Properties, Photoelectric Behavior, and DFT Computational Study of All-Inorganic and Lead-Free Copper Halide Salt K2Cu2Cl6

In this study, all-inorganic copper halide salt K2Cu2Cl6 single-crystal and thin films were prepared. The single-crystal diffraction data belonged to the monoclinic K2Cu2Cl6 (space group = P 2(1)/C, unit cell parameters of a = 4.0340 Å, b = 13.7987 Å, c = 8.7445 Å, α = 90.000, β = 97.123, and γ = 90.000). As far as we know, this is the first study of the copper halide salt K2Cu2Cl6 for optoelectronic applications. The band gap of K2Cu2Cl6 is calculated to be approximately 1.85 eV. A low-cost photodetector based on the K2Cu2Cl6 thin film was efficient under different monochromatic light from 330 to 390 nm with different chopping frequencies (1.33-30 Hz). Density functional theory (DFT) computational results indicate that the valence bands (VBs) and conduction bands (CBs) are shifted up in energy using the orbital-dependent correction to the DFT energy. Partial density of states reveals that the VBs and narrow CBs are derived from the hybrid orbitals of Cu2+ 3d and Cl- p, respectively.

Tuning Ni-Foam into NiOOH/FeOOH Heterostructures toward Superior Water Oxidation Catalyst via Three-Step Strategy

Splitting of water into hydrogen and oxygen has become a strategic research topic. In the two semi-reactions of water splitting, water oxidation is preferred to the four-electron-transfer process with a higher overpotential (η) and is the decisive step in water splitting. Therefore, efficient water oxidation catalysts must be developed. IrO _x and RuO _x catalysts are currently the most efficient catalysts in water oxidation. However, the limited reserve and high prices of precious metals, such as Ir and Ru, limit future large-scale industrial production of water oxidation catalysts. In this study, we tune inert Ni-foam into highly active NiOOH/FeOOH heterostructures as water oxidation catalysts via three-step strategy (surface acid-treating, electroplating, and electrooxidation). NiOOH/FeOOH heterostructures as water oxidation catalysts only require η of 257 mV to reach a current density of 10 mA cm^-2, which is superior to that of IrO₂/Ni-foam (280 mV). The high electrochemically active surface area (72.50 cm²) and roughness factor demonstrate abundant interfaces in NiOOH/FeOOH heterostructures, thus accelerating water oxidation activity. The small value (4.8 Ω cm²) of charge transfer resistance (R _ct) indicate that fast electronic exchange occurs between NiOOH/FeOOH heterostructures catalyst and reaction of water oxidation. Hydrogen-to-oxygen volume ratios (approximately 2:1) indicate an almost overall water splitting by the double-electrode system. Faraday efficiency of H₂ or O₂ is close to 90% at 2:1 hydrogen-to-oxygen volume ratio. NiOOH/FeOOH heterostructures exhibit good stability. The results provide significance in fundamental research and practical applications in solar water splitting, artificial photoelectrochemical cells, and electrocatalysts.

Remote intervention using smartphone for rural women suffering from premenstrual syndrome: A propensity score matched analysis

Timely treatment of premenstrual syndrome (PMS) is not always available for rural women, because the local medical resources are insufficient. The efficacy of remote intervention by smartphone on PMS has not been confirmed.A retrospective analysis was performed on rural PMS patients between January 2014 and December 2015. After a propensity score matched analysis, 60 patients were enrolled and evenly divided into remote group and outpatient group. Multidisciplinary therapy including cognitive-behavioral therapy (CBT), oral medication, and physical exercise education was used individually, in accordance with their symptoms evaluated by Daily Record of Severity of Problems (DRSP) questionnaire. Patients in remote group utilized WeChat software by smartphone for therapy guidance, while those in outpatient group attended face-to-face interview. Their DRSP scores in 5 new menstrual cycles after therapy were recorded. Then, they were followed up for 1 year.Total DRSP scores of the cases in both groups after initial intervention were less than those before therapy (P < .001), without group difference (P > .05). However, patients in remote group indicated a higher satisfactory rate than the outpatient group (P = .03). On the 1-year follow up, patients in both groups demonstrated similar DRSP scores (P = .07), but the satisfactory rate in remote group was encouragingly higher than that in the outpatient group (P = .02).The efficacy of remote intervention using smartphone on PMS is noninferior to traditional outpatient visits. Nevertheless, high-quality trials are needed.

Symptom-triggered alcohol vapor inhalation for postoperative alcohol withdrawal syndrome in patients with gastroesophageal carcinoma

PURPOSE

The purpose of this study was to investigate the feasibility and efficacy of alcohol vapor inhalation during fasting time for cancer patients with alcohol withdrawal symptoms (AWS) after surgery.

METHODS

The data of 51 patients after esophagectomy or gastrectomy for gastroesophageal carcinoma in two hospitals from January 2011 to December 2016 was retrospectively analyzed. These patients were diagnosed with AWS with Clinic Institute Alcohol Withdrawal Syndrome Scale (CIWA-Ar) score ≥ 9 in two hospitals during fasting time from January 2011 to December 2016, and they were accordingly divided into alcohol vapor group (n=25) and diazepam group (n=26). As oral intake of wine was forbidden in the first 7 postoperative days, these patients received either alcohol vapor inhalation or intravenous administration of diazepam every 12 hrs. The difference in scores of CIWA-Ar, Riker Sedation-Agitation Scale (SAS), side effects and complications were registered and analyzed.

RESULTS

The patients in both groups gained satisfactory efficacy which was indicated by CIWA-Ar scores after therapy, without obvious difference in terms of surgery-related complications, chest and abdominal drainage, serum biomarkers of hepatic function or postoperative hospital stay. However, the patients treated with alcohol vapor inhalation displayed lower alcohol craving and sleepiness, more significant decreased CIWA-Ar scores, as well as encouragingly higher degree of satisfaction, comparing with the diazepam group.

CONCLUSION

Alcohol vapor inhalation is feasible and effective to alleviate AWS timely, which is reliable for patients to get through the fasting time after surgery.

Corrigendum: A broadly protective therapeutic antibody against influenza B virus with two mechanisms of action

This corrects the article DOI: 10.1038/ncomms14234.

A broadly protective therapeutic antibody against influenza B virus with two mechanisms of action

Influenza B virus (IBV) causes annual influenza epidemics around the world. Here we use an in vivo plasmablast enrichment technique to isolate a human monoclonal antibody, 46B8 that neutralizes all IBVs tested in vitro and protects mice against lethal challenge of all IBVs tested when administered 72 h post infection. 46B8 demonstrates a superior therapeutic benefit over Tamiflu and has an additive antiviral effect in combination with Tamiflu. 46B8 binds to a conserved epitope in the vestigial esterase domain of hemagglutinin (HA) and blocks HA-mediated membrane fusion. After passage of the B/Brisbane/60/2008 virus in the presence of 46B8, we isolated three resistant clones, all harbouring the same mutation (Ser301Phe) in HA that abolishes 46B8 binding to HA at low pH. Interestingly, 46B8 is still able to protect mice against lethal challenge of the mutant viruses, possibly owing to its ability to mediate antibody-dependent cellular cytotoxicity (ADCC).

Influenza B virus (IBV) co-circulates with influenza A virus to cause annual epidemics. Here, Chai et al. isolate a human monoclonal antibody that binds to a conserved epitope in the viral HA protein, neutralizes IBV strains in vitro, and protects mice against IBV infection.

Layered and Pb-Free Organic-Inorganic Perovskite Materials for Ultraviolet Photoresponse: (010)-Oriented (CH3NH3)2MnCl4 Thin Film

Organic-inorganic lead perovskite materials show impressive performance in photovoltaics, photodetectors, light-emitting diodes, lasers, sensors, medical imaging devices, and other applications. Although organic-inorganic lead perovskites have shown good performance in numerous fields, they contain toxic Pb, which is expected to cause environmental pollution in future large-scale applications. Thus, the photoelectric properties of Pb-free organic-inorganic perovskite materials should be developed and studied. In this paper, we report on the photoresponse of Pb-free organic-inorganic hybrid manganese perovskite (CH₃NH₃)₂MnCl₄. To the best of our knowledge, this study demonstrates the first time that organic-inorganic hybrid manganese perovskites are used for this type of application. We found that the solution-processed MA₂MnCl₄ thin film tends to be oriented along the b-axis direction on the TiO₂ surface. The evident photoresponse of the FTO/TiO₂/MA₂MnCl₄/carbon electrode devices was observed under 10-30 Hz flashlight frequencies and a 330 nm light beam. This simple, green, and low-cost photoresponsive device is beneficial for the future industrial production of optical recorders and optical memory devices.

Two Escape Mechanisms of Influenza A Virus to a Broadly Neutralizing Stalk-Binding Antibody

Broadly neutralizing antibodies targeting the stalk region of influenza A virus (IAV) hemagglutinin (HA) are effective in blocking virus infection both in vitro and in vivo. The highly conserved epitopes recognized by these antibodies are critical for the membrane fusion function of HA and therefore less likely to be permissive for virus mutational escape. Here we report three resistant viruses of the A/Perth/16/2009 strain that were selected in the presence of a broadly neutralizing stalk-binding antibody. The three resistant viruses harbor three different mutations in the HA stalk: (1) Gln387Lys; (2) Asp391Tyr; (3) Asp391Gly. The Gln387Lys mutation completely abolishes binding of the antibody to the HA stalk epitope. The other two mutations, Asp391Tyr and Asp391Gly, do not affect antibody binding at neutral pH and only slightly reduce binding at low pH. Interestingly, they enhance the fusion ability of the HA, representing a novel mechanism that allows productive membrane fusion even in the presence of antibody and hence virus escape from antibody neutralization. Therefore, these mutations illustrate two different resistance mechanisms used by IAV to escape broadly neutralizing stalk-binding antibodies. Compared to the wild type virus, the resistant viruses release fewer progeny viral particles during replication and are more sensitive to Tamiflu, suggesting reduced viral fitness.

IAV causes seasonal epidemics and periodic pandemics that result in significant morbidity and mortality worldwide. The effectiveness of influenza vaccines is highly variable because the virus evolves rapidly and causes antibody mismatch. The use of neuraminidase inhibitors, the current standard of treatment for IAV infection, is limited by their lack of efficacy beyond 48 hours of symptom onset and by the emergence of drug resistant viruses. Recently, broadly neutralizing antibodies targeting the conserved stalk region of IAV HA have been discovered. These antibodies are able to block the infection of many or even all IAV strains, and hold great promise as the next generation of anti-flu treatment. Nonetheless, virus resistance to these antibodies has not been thoroughly studied despite the common view that broadly neutralizing stalk-binding antibodies are less permissive for mutational escape due to the functional importance of their highly conserved epitopes. In this study, we isolated three resistant viruses to a stalk-binding antibody that was previously shown to neutralize all IAV tested. Interestingly, they use two distinct mechanisms to escape the antibody, abolishing antibody binding or enhancing membrane fusion. Our study emphasizes the need to consider novel escape mechanisms when studying virus resistance to broadly neutralizing stalk-binding antibodies.

Delayed noradrenergic activation in the dorsal hippocampus promotes the long-term persistence of extinguished fear

Fear extinction has been extensively studied, but little is known about the molecular processes that underlie the persistence of extinction long-term memory (LTM). We found that microinfusion of norepinephrine (NE) into the CA1 area of the dorsal hippocampus during the early phase (0 h) after extinction enhanced extinction LTM at 2 and 14 days after extinction. Intra-CA1 infusion of NE during the late phase (12 h) after extinction selectively promoted extinction LTM at 14 days after extinction that was blocked by the β-receptor antagonist propranolol, protein kinase A (PKA) inhibitor Rp-cAMPS, and protein synthesis inhibitors anisomycin and emetine. The phosphorylation levels of PKA, cyclic adenosine monophosphate response element-binding protein (CREB), GluR1, and the membrane GluR1 level were increased by NE during the late phase after extinction that was also blocked by propranolol and Rp-cAMPS. These results suggest that the enhancement of extinction LTM persistence induced by NE requires the activation of the β-receptor/PKA/CREB signaling pathway and membrane GluR1 trafficking. Moreover, extinction increased the phosphorylation levels of Erk1/2, CREB, and GluR1, and the membrane GluR1 level during the late phase, and anisomycin/emetine alone disrupted the persistence of extinction LTM, indicating that the persistence of extinction LTM requires late-phase protein synthesis in the CA1. Propranolol and Rp-cAMPS did not completely disrupt the persistence of extinction LTM, suggesting that another β-receptor/PKA-independent mechanism underlies the persistence of extinction LTM. Altogether, our results showed that enhancing hippocampal noradrenergic activity during the late phase after extinction selectively promotes the persistence of extinction LTM.

In vivo antigen-driven plasmablast enrichment in combination with antigen-specific cell sorting to facilitate the isolation of rare monoclonal antibodies from human B cells

The ability to rapidly generate large panels of antigen-specific human antibodies in a rodent would enable the efficient discovery of novel therapeutically useful antibodies. We have developed a system wherein human antigen-specific antibody-secreting plasmablasts can be enriched in vivo, in a severe combined immunodeficient (SCID)/beige mouse host. The antigen-specific plasmablasts can then be sorted by flow cytometry, enabling single-cell cloning and expression of fully human immunoglobulin-G. By using this technique, we have generated four broadly reactive anti-influenza A antibodies. Therefore, the method described here is useful for the identification of rare functional antibodies. This protocol takes ∼1 month to complete, from the time of human vaccination to the cloning of heavy- and light-chain genes. For additional small-scale transient expression, purification and binding analysis, the protocol would take an additional month.

An in vivo human-plasmablast enrichment technique allows rapid identification of therapeutic influenza A antibodies

Recent advances enabling the cloning of human immunoglobulin G genes have proven effective for discovering monoclonal antibodies with therapeutic potential. However, these antibody-discovery methods are often arduous and identify only a few candidates from numerous antibody-secreting plasma cells or plasmablasts. We describe an in vivo enrichment technique that identifies broadly neutralizing human antibodies with high frequency. For this technique, human peripheral blood mononuclear cells from vaccinated donors are activated and enriched in an antigen-specific manner for the production of numerous antigen-specific plasmablasts. Using this technology, we identified four broadly neutralizing influenza A antibodies by screening only 840 human antibodies. Two of these antibodies neutralize every influenza A human isolate tested and perform better than the current anti-influenza A therapeutic, oseltamivir, in treating severe influenza infection in mice and ferrets. Furthermore, these antibodies elicit robust in vivo synergism when combined with oseltamivir, thus highlighting treatment strategies that could benefit influenza-infected patients.