Displaying and delivering viral membrane antigens via WW domain–activated extracellular vesicles

Membrane proteins expressed on the surface of enveloped viruses are conformational antigens readily recognized by B cells of the immune system. An effective vaccine would require the synthesis and delivery of these native conformational antigens in lipid membranes that preserve specific epitope structures. We have created an extracellular vesicle–based technology that allows viral membrane antigens to be selectively recruited onto the surface of WW domain–activated extracellular vesicles (WAEVs). Budding of WAEVs requires secretory carrier-associated membrane protein 3, which through its proline-proline-alanine-tyrosine motif interacts with WW domains to recruit fused viral membrane antigens onto WAEVs. Immunization with influenza and HIV viral membrane proteins displayed on WAEVs elicits production of virus-specific neutralizing antibodies and, in the case of influenza antigens, protects mice from the lethal viral infection. WAEVs thus represent a versatile platform for presenting and delivering membrane antigens as vaccines against influenza, HIV, and potentially many other viral pathogens

Displaying and delivering viral membrane antigens via WW domain–activated extracellular vesicles

Membrane proteins expressed on the surface of enveloped viruses are conformational antigens readily recognized by B cells of the immune system. An effective vaccine would require the synthesis and delivery of these native conformational antigens in lipid membranes that preserve specific epitope structures. We have created an extracellular vesicle–based technology that allows viral membrane antigens to be selectively recruited onto the surface of WW domain–activated extracellular vesicles (WAEVs). Budding of WAEVs requires secretory carrier-associated membrane protein 3, which through its proline-proline-alanine-tyrosine motif interacts with WW domains to recruit fused viral membrane antigens onto WAEVs. Immunization with influenza and HIV viral membrane proteins displayed on WAEVs elicits production of virus-specific neutralizing antibodies and, in the case of influenza antigens, protects mice from the lethal viral infection. WAEVs thus represent a versatile platform for presenting and delivering membrane antigens as vaccines against influenza, HIV, and potentially many other viral pathogens

cTFbase: a database for comparative genomics of transcription factors in cyanobacteria

BACKGROUND: Comprehensive identification and classification of the transcription factors (TFs) in a given genome is an important aspect in understanding transcriptional regulatory networks of a specific organism. Cyanobacteria are an ancient group of gram-negative bacteria with strong variation in genome size ranging from about 1.6 to 9.1 Mb and little is known about their TF repertoires. Therefore, we constructed the cTFbase database to classify and analyze all the putative TFs in cyanobacterial genomes, followed by genome-wide comparative analysis. DESCRIPTION: In the current release, cTFbase contains 1288 putative TFs identified from 21 fully sequenced cyanobacterial genomes. Through its user-friendly interactive interface, users can employ various criteria to retrieve all TF sequences and their detailed annotation information, including sequence features, domain architecture and sequence similarity against the linked databases. Furthermore, cTFbase provides phylogenetic trees of individual TF family, multiple sequence alignments of the DNA-binding domains and ortholog identification from any selected genomes. Comparative analysis revealed great variability of the TF sequences in cyanobacterial genomes. The high variance on the gene number and domain organization would be related to their diverse biological functions and their adaptation to various environmental conditions. CONCLUSION: cTFbase provides a centralized warehouse for comparative analysis of putative TFs in cyanobacterial genomes. The availability of such an extensive database would be of great interest for the community of researchers working on TFs or transcriptional regulatory networks in cyanobacteria. cTFbase can be freely accessible at and will be continuously updated when the newly sequenced cyanobacterial genomes are available

Comparisons of different approaches and incisions of thyroid surgery and selection strategy

To date, the traditional open thyroid surgery via a low collar incision remains the standard approach for patients undergoing thyroidectomy. However, this conventional approach will inevitably leave patients a neck scar and even cause a variety of complications such as paresthesia, hypesthesia, and other uncomfortable sensations. With the progress in surgical techniques, especially in endoscopic surgery, and the increasing desire for cosmetic and functional outcomes, various new approaches for thyroidectomy have been developed to avoid or decrease side effects. Some of these alternative approaches have obvious advantages compared with traditional surgery and have already been widely used in the treatment of thyroid disease, but each has its limitations. This review aims to evaluate and compare the different approaches to thyroidectomy to help surgeons make the proper treatment strategy for different individuals

Serum bilirubin is negatively associated with white blood cell count

OBJECTIVE: Bilirubin is considered an important antioxidant, anti-inflammatory factor and immunomodulator. The current investigation aimed to explore the association between bilirubin and white blood cell (WBC) count in a large Chinese cohort. METHODS: A total of 61091 participants (29259 males, 31832 females) were recruited from a Chinese tertiary hospital. Data were sorted by sex, and the association between bilirubin and WBC count was analyzed after dividing bilirubin levels into quartiles. RESULTS: Most parameters (including age, body mass index, systolic blood pressure, diastolic blood pressure, alanine aminotransferase, total bilirubin, blood urea nitrogen, creatinine, uric acid, triglycerides and WBC count) were significantly higher in men than in women. Bilirubin displayed significant negative relationships with most other measured variables. Linear logistic regression analysis further indicated their negative relationships. Females showed a significantly higher frequency of leucopenia than males. Significant associations of leucopenia with high bilirubin quartiles were shown in binary logistic regression models for both sexes, with a much closer association in men than in women. For instance, for men with bilirubin levels in quartile 4, the adjusted likelihood of leucopenia was 1.600-times higher than that of men with values in quartile 1. For women with bilirubin levels in quartile 4, the adjusted likelihood of leucopenia was 1.135-times higher than that of women with values in quartile 1. CONCLUSION: Bilirubin is negatively related to WBC count. Significant associations exist between leucopenia and high bilirubin quartiles, and these associations are more obvious in men than in women

Progress in Research on the Structure and Activity of Polysaccharides from Chlorella

Chlorella contains a variety of polysaccharides with complex composition and structure, which are composed of various monosaccharides such as galactose, rhamnose, glucose, arabinose, mannose, xylose and glucuronic acid. The glycosidic linkages of polysaccharides are diverse, including α-1,6-glucose, β-1,3-galactose, α-1,6-galactose, α-1,3-rhamnose, α-1,2-rhamnose, α-1,5-arabinose, α-1,6-mannose and β-1,4-xylose. Some polysaccharides are modified by methylation, sulfation and acetylation. Meanwhile, many studies have shown that polysaccharides have multiple functions such as immunoregulatory, anti-inflammatory, antioxidant, anti-tumor, antibacterial and intestinal flora-regulatory effects. At present, monosaccharide composition analysis, methylation combined with gas chromatography-mass spectrometry (GC-MS) and two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy are mainly used for research on the structure of chlorella polysaccharides such as analysis of monosaccharide composition, glycosidic bond types, branch chain substitution positions and branch chain types. This review hopes to provide valuable information for the fine structural analysis and structure-activity relationship study of polysaccharides from Chlorella

Direct Visualization of Gigahertz Acoustic Wave Propagation in Suspended Phononic Circuits

We report direct visualization of gigahertz-frequency Lamb waves propagation in aluminum nitride phononic circuits by transmission-mode microwave impedance microscopy (TMIM). Consistent with the finite-element modeling, the acoustic eigenmodes in both a horn-shaped coupler and a sub-wavelength waveguide are revealed in the TMIM images. Using fast Fourier transform filtering, we quantitatively analyze the acoustic loss of individual Lamb modes along the waveguide and the power coupling coefficient between the waveguide and the parabolic couplers. Our work provides insightful information on the propagation, mode conversion, and attenuation of acoustic waves in piezoelectric nanostructures, which is highly desirable for designing and optimizing phononic devices for microwave signal processing and quantum information transduction.The TMIM work was supported by NSF Division of Materials Research Award DMR-2004536 and Welch Foundation Grant F-1814. The data analysis was partially supported by the NSF through the Center for Dynamics and Control of Materials, an NSF Materials Research Science and Engineering Center (MRSEC) under Cooperative Agreement DMR-1720595. The phononic waveguide work was supported by NSF Award EFMA-1741656 and EFMA-1641109. Part of this work was conducted at the Washington Nanofabrication Facility / Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure (NNCI) site at the University of Washington with partial support from the National Science Foundation via awards NNCI- 1542101 and NNCI-2025489.Center for Dynamics and Control of Material

Identification and characterization of a novel chromosomal aminoglycoside 3’-O-phosphotransferase, APH(3′)-Id, from Kluyvera intermedia DW18 isolated from the sewage of an animal farm

BackgroundAminoglycosides, as important clinical antimicrobials, are used as second-line drugs for treating multidrug-resistant tuberculosis or combined with β-lactam drugs for treating severe infections such as sepsis. Aminoglycoside-modifying enzyme (AME) is the most important mechanism of aminoglycoside resistance and deserves more attention.MethodsThe bacterium Kluyvera intermedia DW18 was isolated from the sewage of an animal farm using the conventional method. The agar dilution method was used to determine the minimum inhibitory concentrations (MICs) of antimicrobials. A novel resistance gene was cloned, and the enzyme was expressed. The kinetic parameters were measured by a SpectraMax M5 multifunctional microplate reader. Bioinformatic analysis was performed to reveal the genetic context of the aph(3′)-Id gene and its phylogenetic relationship with other AMEs.ResultsA novel aminoglycoside 3′-O-phosphotransferase gene designated aph(3′)-Id was identified in K. intermedia DW18 and shared the highest amino acid identity of 77.49% with the functionally characterized aminoglycoside 3′-O-phosphotransferase APH(3′)-Ia. The recombinant plasmid carrying the novel resistance gene (pMD19-aph(3′)-Id/E. coli DH5α) showed 1,024-, 512-, 128- and 16-fold increased MIC levels for kanamycin, ribostamycin, paromomycin and neomycin, respectively, compared with the reference strain DH5α. APH(3′)-Id showed the highest catalytic efficiency for ribostamycin [kcat/Km of (4.96 ± 1.63) × 105 M−1/s−1], followed by paromomycin [kcat/Km of (2.18 ± 0.21) × 105 M−1/s−1], neomycin [kcat/Km of (1.73 ± 0.20) × 105 M−1/s−1], and kanamycin [kcat/Km of (1.10 ± 0.18) × 105 M−1/s−1]. Three conserved functional domains of the aminoglycoside phosphotransferase family and ten amino acid residues responsible for the phosphorylation of kanamycin were found in the amino acid sequence of APH(3′)-Id. No mobile genetic element (MGE) was discovered surrounding the aph(3′)-Id gene.ConclusionIn this work, a novel aminoglycoside 3’-O-phosphotransferase gene designated aph(3′)-Id encoded in the chromosome of the environmental isolate Kluyvera intermedia DW18 was identified and characterized. These findings will help clinicians select effective antimicrobials to treat infections caused by pathogens with this kind of resistance gene

BlaPSZ-1, a novel AmpC gene identified from a Pantoea isolate

BackgroundPantoea species of the family Erwiniaceae are well-known plant pathogens and animal and human conditional pathogens. Due to the widespread and continuous use of antimicrobials, multidrug-resistant strains continue to emerge, making clinical treatment difficult; therefore, there is an increasing need to clarify the mechanisms of drug resistance.MethodsA rabbit anal fecal sample was collected by a swab and the streak plate method was used to isolate single colonies. The standard agar dilution method was used to determine the minimum inhibitory concentrations (MICs) against antimicrobials. The complete genome sequence of the bacterium was obtained using Next-Generation Sequencing platforms. The potential resistance gene was annotated based on the Comprehensive Antibiotic Resistance Database (CARD) and verified by molecular cloning. The β-lactamase PSZ-1 was expressed via the pCold I expression vector and its enzyme kinetic parameters were analyzed. The genetic environment and evolutionary process of the novel resistance gene-related sequences were analyzed by bioinformatic methods.ResultsThe isolate Pantoea endophytica X85 showed some degree of resistance to penicillins as well as cephalosporins. A novel AmpC resistance gene, designated blaPSZ-1 in this research, was identified to be encoded in the plasmid (pPEX85) of P. endophytica X85. BlaPSZ-1 showed resistance to penicillins and several first-, second-and third-generation cephalosporins as well as aztreonam, but it did not show resistance to the fourth-generation cephalosporins or carbapenems tested. Enzyme kinetic assays revealed that it could hydrolyze amoxicillin, penicillin G, cephalothin, and cefazolin, and its hydrolytic activity could be strongly inhibited by the inhibitor avibactam, which was generally consistent with antimicrobial susceptibility testing results. No hydrolytic activity was observed for third-generation cephalosporins or aztreonam.ConclusionIn this study, a novel AmpC β-lactamase gene, designated blaPSZ-1, was characterized and it was encoded in the plasmid of the bacterium P. endophytica X85. It shows resistance to penicillins and several cephalosporins. The discovery of novel drug resistance mechanisms can help guide the scientific use of drugs in animal husbandry and clinical practice, effectively avoiding the abuse of antimicrobials and thus preventing the further development and spread of bacterial resistance

Solidification microstructure variations in additively manufactured Ti-6Al-4V using laser powder bed fusion

Laser powder bed fusion (LPBF) offers unique opportunities to produce metallic components without conventional design and manufacturing constraints. During additive manufacturing process, titanium alloys like Ti-6Al-4V undergo solid-state transformation that conceals initial solidification microstructure from room-temperature observations. Revealing the as-solidified microstructure can be critical to understanding the early stages of solidification. Using orientation relationships between parent (α) and child (β) phases, the as-solidified microstructures across the LPBF build volume has been reconstructed. Based on the as-solidified parent phase information, variations of the thermal and solidification conditions that occur during the LPBF of Ti-6Al-4V are revealed. The results show that how high cooling rates in the initially solidified lower layers contributed to orientation distribution during parent phase solidification, compared to upper layers in the build volume. Furthermore, the approach demonstrates the potential to further explore solidification microstructure and defect formation in titanium alloys during additive manufacturing