Mooring Stone-Like Arg114 Pulls Diverse Bulged Peptides: First Insight into African Swine Fever Virus-Derived T Cell Epitopes Presented by Swine Major Histocompatibility Complex Class I.

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), which is a devastating pig disease threatening the global pork industry. However, currently, no commercial vaccines are available. During the pig immune response, major histocompatibility complex class I (MHC-I) molecules select viral peptide epitopes and present them to host cytotoxic T lymphocytes, thereby playing critical roles in eliminating viral infections. Here, we screened peptides derived from ASFV and determined the molecular basis of ASFV-derived peptides presented by the swine leukocyte antigen 1*0101 (SLA-1*0101). We found that peptide binding in SLA-1*0101 differs from the traditional mammalian binding patterns. Unlike the typical B and F pockets used by the common MHC-I molecule, SLA-1*0101 uses the D and F pockets as major peptide anchor pockets. Furthermore, the conformationally stable Arg114 residue located in the peptide-binding groove (PBG) was highly selective for the peptides. Arg114 draws negatively charged residues at positions P5 to P7 of the peptides, which led to multiple bulged conformations of different peptides binding to SLA-1*0101 and creating diversity for T cell receptor (TCR) docking. Thus, the solid Arg114 residue acts as a "mooring stone" and pulls the peptides into the PBG of SLA-1*0101. Notably, the T cell recognition and activation of p72-derived peptides were verified by SLA-1*0101 tetramer-based flow cytometry in peripheral blood mononuclear cells (PBMCs) of the donor pigs. These results refresh our understanding of MHC-I molecular anchor peptides and provide new insights into vaccine development for the prevention and control of ASF. IMPORTANCE The spread of African swine fever virus (ASFV) has caused enormous losses to the pork industry worldwide. Here, a series of ASFV-derived peptides were identified, which could bind to swine leukocyte antigen 1*0101 (SLA-1*0101), a prevalent SLA allele among Yorkshire pigs. The crystal structure of four ASFV-derived peptides and one foot-and-mouth disease virus (FMDV)-derived peptide complexed with SLA-1*0101 revealed an unusual peptide anchoring mode of SLA-1*0101 with D and F pockets as anchoring pockets. Negatively charged residues are preferred within the middle portion of SLA-1*0101-binding peptides. Notably, we determined an unexpected role of Arg114 of SLA-1*0101 as a "mooring stone" which pulls the peptide anchoring into the PBG in diverse "M"- or "n"-shaped conformation. Furthermore, T cells from donor pigs could activate through the recognition of ASFV-derived peptides. Our study sheds light on the uncommon presentation of ASFV peptides by swine MHC-I and benefits the development of ASF vaccines.

Transcription Factor Atf1 Regulates Expression of Cellulase and Xylanase Genes during Solid-State Fermentation of Ascomycetes.

Transcriptional regulation of cellulolytic and xylolytic genes in ascomycete fungi is controlled by specific carbon sources in different external environments. Here, comparative transcriptomic analyses of Penicillium oxalicum grown on wheat bran (WB), WB plus rice straw (WR), or WB plus Avicel (WA) as the sole carbon source under solid-state fermentation (SSF) revealed that most of the differentially expressed genes (DEGs) were involved in metabolism, specifically, carbohydrate metabolism. Of the DEGs, the basic core carbohydrate-active enzyme-encoding genes which responded to the plant biomass resources were identified in P. oxalicum, and their transcriptional levels changed to various extents depending on the different carbon sources. Moreover, this study found that three deletion mutants of genes encoding putative transcription factors showed significant alterations in filter paper cellulase production compared with that of a parental P. oxalicum strain with a deletion of Ku70 (ΔPoxKu70 strain) when grown on WR under SSF. Importantly, the ΔPoxAtf1 mutant (with a deletion of P. oxalicumAtf1, also called POX03016) displayed 46.1 to 183.2% more cellulase and xylanase production than a ΔPoxKu70 mutant after 2 days of growth on WR. RNA sequencing and quantitative reverse transcription-PCR revealed that PoxAtf1 dynamically regulated the expression of major cellulase and xylanase genes under SSF. PoxAtf1 bound to the promoter regions of the key cellulase and xylanase genes in vitro This study provides novel insights into the regulatory mechanism of fungal cellulase and xylanase gene expression under SSF.IMPORTANCE The transition to a more environmentally friendly economy encourages studies involving the high-value-added utilization of lignocellulosic biomass. Solid-state fermentation (SSF), that simulates the natural habitat of soil microorganisms, is used for a variety of applications such as biomass biorefinery. Prior to the current study, our understanding of genome-wide gene expression and of the regulation of gene expression of lignocellulose-degrading enzymes in ascomycete fungi during SSF was limited. Here, we employed RNA sequencing and genetic analyses to investigate transcriptomes of Penicillium oxalicum strain EU2101 cultured on medium containing different carbon sources and to identify and characterize transcription factors for regulating the expression of cellulase and xylanase genes during SSF. The results generated will provide novel insights into genetic engineering of filamentous fungi to further increase enzyme production.

Transcription Factor NsdD Regulates the Expression of Genes Involved in Plant Biomass-Degrading Enzymes, Conidiation, and Pigment Biosynthesis in Penicillium oxalicum.

Soil fungi produce a wide range of chemical compounds and enzymes with potential for applications in medicine and biotechnology. Cellular processes in soil fungi are highly dependent on the regulation under environmentally induced stress, but most of the underlying mechanisms remain unclear. Previous work identified a key GATA-type transcription factor, Penicillium oxalicum NsdD (PoxNsdD; also called POX08415), that regulates the expression of cellulase and xylanase genes in P. oxalicum PoxNsdD shares 57 to 64% identity with the key activator NsdD, involved in asexual development in Aspergillus In the present study, the regulatory roles of PoxNsdD in P. oxalicum were further explored. Comparative transcriptomic profiling revealed that PoxNsdD regulates major genes involved in starch, cellulose, and hemicellulose degradation, as well as conidiation and pigment biosynthesis. Subsequent experiments confirmed that a ΔPoxNsdD strain lost 43.9 to 78.8% of starch-digesting enzyme activity when grown on soluble corn starch, and it produced 54.9 to 146.0% more conidia than the ΔPoxKu70 parental strain. During cultivation, ΔPoxNsdD cultures changed color, from pale orange to brick red, while the ΔPoxKu70 cultures remained bluish white. Real-time quantitative reverse transcription-PCR showed that PoxNsdD dynamically regulated the expression of a glucoamylase gene (POX01356/Amy15A), an α-amylase gene (POX09352/Amy13A), and a regulatory gene (POX03890/amyR), as well as a polyketide synthase gene (POX01430/alb1/wA) for yellow pigment biosynthesis and a conidiation-regulated gene (POX06534/brlA). Moreover, in vitro binding experiments showed that PoxNsdD bound the promoter regions of the above-described genes. This work provides novel insights into the regulatory mechanisms of fungal cellular processes and may assist in genetic engineering of Poxalicum for potential industrial and medical applications.IMPORTANCE Most filamentous fungi produce a vast number of extracellular enzymes that are used commercially for biorefineries of plant biomass to produce biofuels and value-added chemicals, which might promote the transition to a more environmentally friendly economy. The expression of these extracellular enzyme genes is tightly controlled at the transcriptional level, which limits their yields. Hitherto our understanding of the regulation of expression of plant biomass-degrading enzyme genes in filamentous fungi has been rather limited. In the present study, regulatory roles of a key regulator, PoxNsdD, were further explored in the soil fungus Penicillium oxalicum, contributing to the understanding of gene regulation in filamentous fungi and revealing the biotechnological potential of Poxalicum via genetic engineering.

A novel cleaning process for industrial production of xylose in pilot scale from corncob by using screw-steam-explosive extruder.

Steam explosion is the most promising technology to replace conventional acid hydrolysis of lignocellulose for biomass pretreatment. In this paper, a new screw-steam-explosive extruder was designed and explored for xylose production and lignocellulose biorefinery at the pilot scale. We investigated the effect of different chemicals on xylose yield in the screw-steam-explosive extrusion process, and the xylose production process was optimized as followings: After pre-impregnation with sulfuric acid at 80 °C for 3 h, corncob was treated at 1.55 MPa with 9 mg sulfuric acid/g dry corncob (DC) for 5.5 min, followed by countercurrent extraction (3 recycles), decoloration (activated carbon dosage 0.07 g/g sugar, 75 °C for 40 min), and ion exchange (2 batches). Using this process, 3.575 kg of crystal xylose was produced from 22 kg corncob, almost 90 % of hemicellulose was released as monomeric sugar, and only a small amount of by-products was released (formic acid, acetic acid, fural, 5-hydroxymethylfurfural, and phenolic compounds were 0.17, 1.14, 0.53, 0.19, and 1.75 g/100 g DC, respectively). All results indicated that the screw-steam-explosive extrusion provides a more effective way to convert hemicellulose into xylose and could be an alternative method to traditional sulfuric acid hydrolysis process for lignocellulose biorefinery.

A universal eco-friendly flame retardant strategy for polylactic acid fabrics and other polymer substrates.

Various polymer substrates have their particular combustion features, therefore, developing an effective universal flame retardant strategy for various polymer substrates is of great practical importance. Meanwhile, as substitutes for petroleum-based products, bio-based flame retardants and biodegradable polylactic acid (PLA) meet the requirements of sustainable development. In this work, a fully bio-based flame retardant coating (PAGS) was prepared using phytic acid (PA) and guanosine (GS). PAGS was used as a universal flame retardant coatings for polylactic acid (PLA) fabrics and other substrates, including cotton fabrics, polyethylene terephthalate (PET) fabrics, polyamide (PA) fabrics, polyurethane (PU) foams, polyethylene terephthalate (PET) films, and woods. The PAGS-treated substrates were able to self-extinguish and eliminate molten droplets. Similarly, the PAGS coating significantly suppressed the heat release of each substrate. The P-containing free radicals in the gas phase were able to interact with highly reactive H, HO and alkyl radicals, blocking the chain reaction during combustion. The flammable gas density was also diluted by nonflammable gases. The formed continuous porous and dense intumescent char layer hindered heat and oxygen. It is suggested that this work provides a simple and efficient flame retardant strategy for improving the fire safety of various polymer substrates.

Environmental benign foam finishing with a hyperbranched polyphosphonate flame retardant for polyethylene terephthalate fabric.

It is still a big challenge for textile industry in improving fire resistance and reducing melt dripping with minimal loss on the physical properties of polyethylene terephthalate (PET) fabrics. In this work, a highly-effective hyperbranched flame retardant (DT) was first synthesized by ester exchange without using any organic solvent. Then, the DT foam was prepared and blade coated on PET fabric to improve the fire performance. The prepared PET fabric with only 2.7% weight gain of DT was self-extinguished and did not produce any molten dripping during the vertical flammable test. The peak heat release rate and total heat release of the PET fabric sample with 19.4% DT were decreased by 42.0% and 57.1%, respectively compared with that of the control PET. Besides, the as-prepared PET fabric sample showed better physical properties such as breaking strength, vapor permeability, air permeability, antistatic property, and softness than the control PET fabric sample. The DT foam finishing process did not involve any organic solvent and consumed less water and energy compared with conventional fabric treatments. It is expected that this work provides a facile and eco-friendly strategy for fabricating flame retardant PET fabric with excellent comprehensive performances.

Enhancing the flame retardancy and UV resistance of polyamide 6 by introducing ternary supramolecular aggregates.

An integrated multi-functional additive was fabricated by successively grafting melamine (MEL) and phytic acid (PhA) on multiwalled carbon-nanotubes (MWNCTs), and was then applied in PA6 to improve the flame retardancy and light aging resistance of the composite. The limit oxygen index of PA6 composite containing 7 wt% PhA-MEL-MWCNTs was increased to 26.4 from 21.0. The smoke and CO release were significantly reduced by 48% and 88% respectively, and the severe melt dripping of PA6 in burning was eliminated. It is proved that PhA-MEL-MWCNTs can absorb ultraviolet (UV) radiation, and hence significantly reduces the mechanical property loss of the PA6 composite after UV aging. The tensile strength of the aged PA6/7 wt%PhA-MEL-MWCNTs composite sample only decreased by 18.1%, which was significantly lower than the loss rate of the control aged PA6 sample (62.5%). This protocol provides a new opportunity for fabricating long-life flame retardant polyamide composites.

Improving the flame retardancy and accelerating the degradation of poly (lactic acid) in soil by introducing fully bio-based additives.

In this study, a novel bio-based flame retardant LC-PA is prepared by the Mannich reaction between phytic acid (PA) and L-citrulline (LC). LC-PA is combined with tannic acid (TA) and introduced into PLA to improve fire performance and accelerate biodegradability. Compared with control PLA, the PLA composite containing 10% LC-PA/TA increases the LOI value to 26.9%, reaches a V-0 rating in the UL-94 test, and reduces the peak heat release rate and total heat release by 24.5% and 21.1%, respectively. More importantly, the introduction of LC-PA/TA accelerates the degradation rate of PLA in soil, which is of significance for biodegradable materials. The addition of LC-PA/TA can attract water and provide a suitable energy source for microbial proliferation, accelerating the hydrolysis and microbial degradation of PLA. This work provides a practical approach for high flame retardancy and rapid biodegradability in the soil to the bio-based polymer.

Crystallization of SLA-2*04:02:02 complexed with a CTL epitope derived from FMDV.

Presentation of viral epitopes by swine MHC I (termed leukocyte antigen class I, SLA I) to cytotoxic T lymphocytes (CTLs) is crucial for swine immunity. The SLA-2 structure, however, remains largely unknown. To illustrate the structural basis of swine CTL epitope presentation, the crystal structure of SLA-2*04:02:02 complexed with one peptide, derived from foot-and-mouth disease virus (FMDV), was analyzed in this study. SLA-2*04:02:02 and swine ß2-microglobulin (sß2m) were refolded in vitro in the presence of peptides. X-ray diffraction data of SLA-2*04:02:02-peptide-sß2m (referred to as p/SLA-2*04:02:02) were collected. The diffraction dataset was 2.3 Šin resolution and the space group was P3(2)21. Relevant data included a = 101.8 Å, b = 101.8 Å, c = 73.455 Å,α = 90.00°, ß = 90.00°, γ = 120.00°. The structure of p/SLA-2*04:02:02 was analyzed. The results revealed that Glu24, Met68, Gly76, and Gln173 in PBG of SLA-2*04:02:02 are different from other MHC I. Furthermore, Asn63 is different from other SLA I. Gln57, Met174 and Gln180 in PBG of SLA I are different from other species' MHC I. All of these features are different from known mammalian peptide-MHC class I complexes (referred to as p/MHC I). In addition, P4-His, P6-Val, and P8-Pro in the peptide were exposed, and these residues as epitopes can be presented by SLA-2*04:02:02. This study not only provides a structural basis for peptide presentation by SLA-2, but also screens one potential FMDV CTL epitope. The results may be of interest in future vaccine development.

[Effects of plastic film mulching patterns on maize grain yield, water use efficiency, and soil water balance in the farming system with one film used two years.] / 覆膜方式对一膜两年覆盖旱地玉米籽粒产量、水分利用效率和土壤水分平衡的影响.

The aim of this study was to develop cost-saving and efficiency-improving technologies in whole plastic mulching and double ridge-furrow maize in semi-arid region of Loess Plateau. The objective was to investigate soil water balance in farming system with one film used two years. A field experiment was conducted to investigate the effects of different mulching and tillage patterns under one film used two years conditions on the yield, economic benefits, and water use efficiency of maize. There are four treatments: Ridge-furrow planting with complete plastic film mulching, F1M; flat-planting with complete plastic film mulching, F2M; flat-planting with half plastic film mulching, F3M; and flat-planting without mulching, F4M, the control. The results showed that the F1M and F2M treatments had significant effects on the improvement of the production and efficiency compared with the control. The F1M and F2M treatments improved biomass by 32.8% and 32.9%, enhanced grain yield by 60.0% and 51.7%. Water use efficiency and rainfall use efficiency in F1M and F2M treatments were increased by 59.8%, 35.9% and 87.6%, 64.4%, respectively. Furthermore, gross output value and input-output ratio of F1M and F2M treatments under every new plastic film mulched pattern were enhanced by 51.0%, 41.2% and 15.1%, 16.2%, respectively. The production pattern on cost-saving and efficiency-increasing of the system on double ridge-furrow and flat planting with one film used two years, this pattern increased gross output value by 40.8%, 42.2%, and increased input-output ratio by 40.3%, 42.2%, respectively. Under the condition of low precipitation (606.5 mm), total water consumption of ridge-furrow and flat planting under the system of one film used within two years was 731.3 mm and 746.8 mm, the soil moisture deficit was 124.8 mm and 140.3 mm, with enhancement of 22.7% and 38.0%, respectively. The total water consumption of ridge-furrow and flat planting treatments was reduced by 28.6% and 30.0%, and the fallow efficiency was improved by 178.9% and 148.3%. In conclusion, whole plastic mulching with double ridge-furrow and flat planting farming system had positive effects on yield and water use efficiency in semi-arid region of Loess Plateau. Combined with the technology of one film used within two years, this cropping system could be cost saving and efficiency increasing. However, the water deficit under low water condition should be seriously considered in practice.

Stiffness Customization and Patterning for Property Modulation of Silicone-Based Soft Pneumatic Actuators.

Soft pneumatic actuators (SPAs), as novel types of motion drivers for robotic devices, excel in many applications, such as rehabilitation and biomimicry, which demand compliance and softness. To further expand their scope of utilization, the SPAs should be customizable to meet the distinctive requirements of different applications. This article proposes a novel perspective on the SPA working mechanism based on stiffness distribution and then presents a versatile method called stiffness customization and patterning (SCP) for SPA body stiffness layout as a novel attempt to customize SPAs with distinctive properties. We fabricated a hybrid type of material combining unstretchable material and silicone with customizable aggregated elasticity. The tensile results showed that embedding unstretchable material directly increases the stiffness of the hybrid material sample, and our stress-strain model for SCP is able to adequately predict the elasticity of hybrid samples with specific material ratios. By applying this approach to bending-type SPAs, we are able to mitigate SPA buckling, a main failure mode of SPAs, and improve the SPA tip force by using hybrid material with globally increased stiffness. We also diversify bending modalities with different stiffness configurations in the hybrid material. SCP offers numerous ways to engineer SPAs for more applications.

Quaternized magnetic nanoparticles-fluorescent polymer system for detection and identification of bacteria.

Nanomaterial-based 'chemical nose' sensor with sufficient sensing specificity is a useful analytical tool for the detection of toxicologically important substances in complicated biological systems. A sensor array containing three quaternized magnetic nanoparticles (q-MNPs)-fluorescent polymer systems has been designed to identify and quantify bacteria. The bacterial cell membranes disrupt the q-MNP-fluorescent polymer, generating unique fluorescence response array. The response intensity of the array is dependent on the level of displacement determined by the relative q-MNP-fluorescent polymer binding strength and bacteria cells-MNP interaction. These characteristic responses show a highly repeatable bacteria cells and can be differentiated by linear discriminant analysis (LDA). Based on the array response matrix from LDA, our approach has been used to measure bacteria with an accuracy of 87.5% for 10(7) cfu mL(-1) within 20 min. Combined with UV-vis measurement, the method can be successfully performed to identify and detect eight different pathogen samples with an accuracy of 96.8%. The measurement system has a potential for further applications and provides a facile and simple method for the rapid analysis of protein, DNA, and pathogens.

[Study on the thickness-change of different thickness thermoplastic materials after thermoforming and saliva immersion].

OBJECTIVE: To survey and compare the thickness-change of different thickness thermoplastic materials under different test condition and make sure the relationship between the thickness-change and the material initial thickness in order to provide a guide in selecting the suitable thickness thermoplastic in practice. METHODS: To choose Biolon, the thickness include 1.0 mm, 0.75 mm, 0.5 mm. Used Electron Vernier caliper to measure the thickness-change of different thickness thermoplastic materials under different processing mode. The data was analyzed by SPSS 10.0. RESULTS: After thermoforming the thickness of thermoplastic became thinner, the thickness of Biolon 0.75 mm decreased by 0.14 mm, Biolon 1.0 mm decreased by 0.22 mm and Biolon 0.5 mm decreased by 0.14 mm. After saliva immersion the thickness became thicker. The thickness of Biolon 0.75 mm increased by 0.02 mm, Biolon 1.0 mm increased by 0.03 mm and Biolon 0.5 mm increased by 0.02 mm. CONCLUSION: 1)The influence of different processing mode to the thickness-change had relation to the material initial thickness. 2)The Biolon 0.75 mm had certain superiority in thickness stability compared to the homogeneous brand through the above research.

[Patients with anterior spaces caused by periodontal disease treated with aligner technique].

OBJECTIVE: To treat the patients with anterior spaces caused by periodontal diseases with aligners and evaluate the periodontal conditions before and after treatment. METHODS: Seven patients with anterior spaces ranged from 3.0 to 4.5 mm were randomly selected. All the patients were treated with aligner technique to close the spaces. Bleeding on probing (BOP) and probing depth (PD) were measured before treatment, 1 month, 3 months and 6 months after treatment. The CEJ-ABC distance was evaluated before treatment, 1 month, and 6 months after treatment. RESULTS: No significant differences were found in periodontal evaluation and the CEJ-ABC distance between any two evaluated stages. CONCLUSIONS: The aligners could be used in patients with anterior spaces caused by periodontal diseases. No periodontal tissue damages were found during the observation period.

Preparation and characterization of poly glycidyl methacrylete-zirconium dioxide-beta-cyclodextrin composite matrix for separation of isoflavones through expanded bed adsorption.

The specially prepared adsorbent is most important in realizing the expanded bed adsorption (EBA) process. In the present work, a novel poly glycidyl methacrylete-zirconium dioxide-beta-cyclodextrin (PGMA-ZrO(2)-beta-CD) composite matrix for EBA has been first prepared. Wet density, water content and pore properties of the composite beads have been investigated, which shows good expansion and stability in EBA. The application of custom-made adsorbent has been investigated to recover isoflavones from soy molasses. The recovery is up to 90% and the purity of isoflavones obtained is 75.4%. Compared with the traditional purification processes, EBA has the advantage of high efficiency and integrality, which leads to large reduction in operation time and cost.

[Preliminary clinical application of Chinese-made invisible orthodontic technique].

OBJECTIVE: To treat simple malocclusions preliminarily using Chinese-made invisible orthodontic aligners and discuss the indications, problems existed and future development. METHODS: Forty-one cases with different malocclusions were selected, including crowding, spaces and spaces due to periodontal problems. Invisible aligners were made and worn by patients and they were changed every 2 - 3 weeks. RESULTS: Acceptable treatment results were obtained in all cases, with nice alignments and good overbite and overjet. Treatment time ranged from 6 - 25 months. CONCLUSIONS: Indications of this technique were still limited and the technique needed to be further developed in the future.