ABSTRACT
Sorghum (Sorghum bicolor), the fifth most important cereal crop globally, serves as a staple food, animal feed, and a bioenergy source. Paclobutrazol-Resistance (PRE) genes play a pivotal role in the response to environmental stress, yet the understanding of their involvement in pest resistance remains limited. In the present study, a total of seven SbPRE genes were found within the sorghum BTx623 genome. Subsequently, their genomic location was studied, and they were distributed on four chromosomes. An analysis of cis-acting elements in SbPRE promoters revealed that various elements were associated with hormones and stress responses. Expression pattern analysis showed differentially tissue-specific expression profiles among SbPRE genes. The expression of some SbPRE genes can be induced by abiotic stress and aphid treatments. Furthermore, through phytohormones and transgenic analyses, we demonstrated that SbPRE4 improves sorghum resistance to aphids by accumulating jasmonic acids (JAs) in transgenic Arabidopsis, giving insights into the molecular and biological function of atypical basic helix-loop-helix (bHLH) transcription factors in sorghum pest resistance.
Subject(s)
Aphids , Gene Expression Regulation, Plant , Plant Proteins , Sorghum , Stress, Physiological , Triazoles , Sorghum/genetics , Sorghum/metabolism , Aphids/genetics , Aphids/physiology , Animals , Triazoles/pharmacology , Stress, Physiological/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified , Oxylipins/metabolism , Oxylipins/pharmacology , Cyclopentanes/metabolism , Cyclopentanes/pharmacology , Arabidopsis/genetics , Promoter Regions, Genetic , Multigene Family , Plant Growth Regulators/metabolism , Plant Growth Regulators/pharmacology , Phylogeny , Plant Diseases/parasitology , Plant Diseases/genetics , Genome, PlantABSTRACT
China has been continuously improving its monitoring methods and strategies to address key infectious diseases (KIDs). After the severe acute respiratory syndrome epidemic in 2003, China established a comprehensive reporting system for infectious diseases (IDs) and public health emergencies. The relatively lagging warning thresholds, limited warning information, and outdated warning technology are insufficient to meet the needs of comprehensive monitoring for modern KIDs. Strengthening early monitoring and warning capabilities to enhance the public health system has become a top priority, with increasing demand for early warning thresholds, information, and techniques, thanks to constant innovation and development in molecular biology, bioinformatics, artificial intelligence, and other identification and analysis technologies. A panel of 31 experts has recommended a fourth-generation comprehensive surveillance system targeting KIDs (41 notifiable diseases and emerging IDs). The aim of this surveillance system is to systematically monitor the epidemiology and causal pathogens of KIDs in hosts such as humans, animals, and vectors, along with associated environmental pathogens. By integrating factors influencing epidemic spread and risk assessment, the surveillance system can serve to detect, predict, and provide early warnings for the occurrence, development, variation, and spread of known or novel KIDs. Moreover, we recommend comprehensive ID monitoring based on the fourth-generation surveillance system, along with a data-integrated monitoring and early warning platform and a consortium pathogen detection technology system. This series of considerations is based on systematic and comprehensive monitoring across multiple sectors, dimensions, factors, and pathogens that is supported by data integration and connectivity. This expert consensus will provides an opportunity for collaboration in various fields and relies on interdisciplinary application to enhance comprehensive monitoring, prediction, and early warning capabilities for the next generation of ID surveillance. This expert consensus will serve as a reference for ID prevention and control as well as other related activities.
ABSTRACT
BACKGROUND: The Omicron wave of Coronavirus disease 2019 (COVID-19) remains the dominant strain worldwide. The studies of nutritional status in geriatric people with COVID-19 Omicron variant are limited. Thus, the aim of this study was to investigate the incidence of poor nutritional status among Omicron infected older patients, and to explore the correlation between the nutritional status and the severity of Omicron infection in older patients. METHODS: This is a retrospective cross-sectional study. According to the clinical symptoms, patients were divided into two groups: mild and moderate to severe. Mini Nutritional Assessment short-form (MNA-SF) was conducted when patients were admitted and poor nutritional status was defined as MNA-SF score of 0-11. The inflammatory markers including neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and systemic inflammatory index (SII) were calculated and compared between two groups. RESULTS: Total of 324 patients were enrolled, with median [interquartile range (IQR)] age of 73 (17) years. Overall, 241 cases were mild, 83 cases were moderate to severe at the time of diagnosis and that 54.3% of patients had poor nutritional status. Patients with poor nutritional status were found to be older (P < 0.001) and less vaccinated (P < 0.001), with a longer virus shedding duration (P = 0.022), more comorbidities (≥ 2) (P = 0.004) and higher value of NLR (P < 0.001), PLR (P < 0.001) and SII (P = 0.012). Vaccination, cycle threshold value in ORF1ab gene (OR CT value) and female, higher MNA-SF score was negatively connected with probability of moderate to severe infection. For every 1 score increase in MNA-SF, the odds ratio of moderate to severe infection decreased by 14.8% [adjusted odds ratio (aOR), 0.852; 95% confidence interval (CI): 0.734-0.988; P = 0.034]. CONCLUSIONS: Older patients with poor nutritional status are more likely to develop moderate to severe Omicron infection.
Subject(s)
COVID-19 , Malnutrition , Humans , Female , Aged , Nutritional Status , Retrospective Studies , Cross-Sectional Studies , Malnutrition/epidemiology , Nutrition Assessment , COVID-19/epidemiologyABSTRACT
Background: Nutrition is an important prevention in old patients with COVID-19. However, in China, there are few studies on the correlation between nutrition and COVID-19. Methods: A total of 148 hospitalized COVID-19 (65.7 ± 16.0 [range: from 21 to 101] years old) patients were enrolled in this study. The information of demographic, biochemical results, vaccination doses, types of COVID-19, PCR test negative conversion time, and scores of Mini Nutritional Assessment Short Form (MNA-SF) for evaluating nutritional status were recorded. We first explored the relationships between MNA-SF performance and the severities of COVID-19 in the groups with non-vaccinated, vaccinated, and all the patients using multivariable ordinal logistic regression. Further, we explored the relationships between performance of MNA-SF and the time of negative conversion of PCR in the groups with non-vaccinated, vaccinated, and all the patients using COX proportional hazards survival regression. Results: Group of patients with malnutrition or at risk of malnutrition group was associated with older of the age, those who had not been vaccinated, in fewer people who were asymptomatic type and in more people who showed longer of the negative conversion time of PCR, lower of the BMI, and the lower of the hemoglobin level. Each additional increase of one point of MNA-SF was associated with a 17% decrease in the odds of a worse type of COVID-19 in all patients, and the significant result exists in non-vaccinated patients. One point increase of MNA-SF was associated with increased 11% of hazard ratios of turning negative of PCR and well-nourished group was associated with increased 46% of hazard ratio of turning negative of PCR. Conclusion: Higher nutrition is associated with less severity of COVID-19, especially in the non-vaccinated group. Higher nutrition is also associated with shorter time of turning negative of PCR in non-ICU COVID-19 patients.
ABSTRACT
BACKGROUND: Population-specific variation database of inborn errors of metabolism (IEMs) is essential for precise genetic diagnosis and disease prevention. Here we presented a systematic review of clinically relevant variants of 13 IEMs genes reported among Chinese patients. METHODS: A systematic search of the following electronic databases for 13 IEMs genes was conducted: PubMed-NCBI, China national knowledge infrastructure and Wanfang databases. Patient data was extracted from articles eligible for inclusion and recorded in Excel electronic form using a case-by-case approach. RESULTS: A total of 218 articles, 93 published in English and 125 in Chinese, were retrieved. After variant annotation and deduplication, 575 unique patients (241 from articles published in Chinese) were included in the population-specific variation database. Patients identified by newborn screening and symptomatic presentation were 231 (40.17%) and 344 (59.83%), respectively. Biallelic variants were observed in 525/575 (91.3%). Among the 581 unique variants identified, 83 (14.28%) were described ≥ 3 times and 97 (16.69%) were not recorded in Clinvar or HGMD. Four variants were reclassified as benign and dozens of confusing variants deserved further research. CONCLUSION: This review provides a unique resource of the well-characterized diseases and causative variants that have accumulated in Chinese population and is a preliminary attempt to build the Chinese genetic variation database of IEMs.
Subject(s)
East Asian People , Metabolism, Inborn Errors , Humans , Infant, Newborn , China , Genetic VariationABSTRACT
BACKGROUND: Next-generation sequencing (NGS) has been suggested as a second-tier diagnostic test for newborn screening, which could help identify the carrier status of hundreds monogenic disorders with wider spectrum and earlier stage. METHODS: Among the 1087 children (age from 27 min to 14 years old) underwent liquid chromatography-tandem mass spectrometry (LC-MS/MS), 290 individuals who had at least one abnormal value of LC-MS/MS measurements were sent for amplicon sequencing-based carrier screening (targeting 141 genes for 170 monogenic disorders). Multiplex polymerase chain reaction was used for amplicon capture and library preparation, the NextSeq 500 NGS platform (Illumina PE150) was used for sequencing. The identified clinical significant variants were further validated by Sanger sequencing. RESULTS: Only 89 children carry none of clinical significant variants, other 201 individuals carry 1-4 variants in 63 genes (132 types; 317 in total: 171 pathogenic, 37 likely pathogenic, 29 variants of unknown significance, and 80 disease-associated functional polymorphisms). Besides the three missing samples with 4 variants, 91.1 % of identified variants (285 variants in 54 genes) were completely validated by Sanger sequencing. The most common genetic variants were in UGT1A1, GJB2, PAH, G6PD, and SLC25A13 (top 5 genes), which corresponding to Gilbert/Crigler-Najjar symdrome (n = 89), autosomal recessive hearing loss type 1A (n = 58), phenylketonuria (n = 12), glucose-6-phosphate dehydrogenease deficiency (n = 11) and Citrin deficiency (n = 9). More than 42 children present higher phenylalanine in LC-MS/MS, but only 12 of them were identified to carry clinical significant variants in PAH gene. CONCLUSION: The amplicon sequencing-based carrier screening in our study could further clarify the abnormal LC-MS/MS results, which could also discover more monogenic disorders uncovered by LC-MS/MS screening.
Subject(s)
Citrullinemia , Phenylketonurias , Infant, Newborn , Humans , Child , Tandem Mass Spectrometry/methods , Chromatography, Liquid , Neonatal Screening/methods , High-Throughput Nucleotide Sequencing/methods , Mitochondrial Membrane Transport Proteins/geneticsABSTRACT
Whole genome sequencing (WGS) can provide insight into drug-resistance, transmission chains and the identification of outbreaks, but data analysis remains an obstacle to its routine clinical use. Although several drug-resistance prediction tools have appeared, until now no website integrates drug-resistance prediction with strain genetic relationships and species identification of nontuberculous mycobacteria (NTM). We have established a free, function-rich, user-friendly online platform for MTB WGS data analysis (SAM-TB, http://samtb.szmbzx.com) that integrates drug-resistance prediction for 17 antituberculosis drugs, detection of variants, analysis of genetic relationships and NTM species identification. The accuracy of SAM-TB in predicting drug-resistance was assessed using 3177 sequenced clinical isolates with results of phenotypic drug-susceptibility tests (pDST). Compared to pDST, the sensitivity of SAM-TB for detecting multidrug-resistant tuberculosis was 93.9% [95% confidence interval (CI) 92.6-95.1%] with specificity of 96.2% (95% CI 95.2-97.1%). SAM-TB also analyzes the genetic relationships between multiple strains by reconstructing phylogenetic trees and calculating pairwise single nucleotide polymorphism (SNP) distances to identify genomic clusters. The incorporated mlstverse software identifies NTM species with an accuracy of 98.2% and Kraken2 software can detect mixed MTB and NTM samples. SAM-TB also has the capacity to share both sequence data and analysis between users. SAM-TB is a multifunctional integrated website that uses WGS raw data to accurately predict antituberculosis drug-resistance profiles, analyze genetic relationships between multiple strains and identify NTM species and mixed samples containing both NTM and MTB. SAM-TB is a useful tool for guiding both treatment and epidemiological investigation.
Subject(s)
Mycobacterium tuberculosis , Antitubercular Agents/pharmacology , Antitubercular Agents/therapeutic use , Data Analysis , Drug Resistance , Phylogeny , Whole Genome Sequencing/methodsABSTRACT
Recently, crop breeders have widely adopted a new biotechnology-based process, termed Seed Production Technology (SPT), to produce hybrid varieties. The SPT does not produce nuclear male-sterile lines, and instead utilizes transgenic SPT maintainer lines to pollinate male-sterile plants for propagation of nuclear-recessive male-sterile lines. A late-stage pollen-specific promoter is an essential component of the pollen-inactivating cassette used by the SPT maintainers. While a number of plant pollen-specific promoters have been reported so far, their usefulness in SPT has remained limited. To increase the repertoire of pollen-specific promoters for the maize community, we conducted a comprehensive comparative analysis of transcriptome profiles of mature pollen and mature anthers against other tissue types. We found that maize pollen has much less expressed genes (>1 FPKM) than other tissue types, but the pollen grain has a large set of distinct genes, called pollen-specific genes, which are exclusively or much higher (100 folds) expressed in pollen than other tissue types. Utilizing transcript abundance and correlation coefficient analysis, 1215 mature pollen-specific (MPS) genes and 1009 mature anther-specific (MAS) genes were identified in B73 transcriptome. These two gene sets had similar GO term and KEGG pathway enrichment patterns, indicating that their members share similar functions in the maize reproductive process. Of the genes, 623 were shared between the two sets, called mature anther- and pollen-specific (MAPS) genes, which represent the late-stage pollen-specific genes of the maize genome. Functional annotation analysis of MAPS showed that 447 MAPS genes (71.7% of MAPS) belonged to genes encoding pollen allergen protein. Their 2-kb promoters were analyzed for cis-element enrichment and six well-known pollen-specific cis-elements (AGAAA, TCCACCA, TGTGGTT, [TA]AAAG, AAATGA, and TTTCT) were found highly enriched in the promoters of MAPS. Interestingly, JA-responsive cis-element GCC box (GCCGCC) and ABA-responsive cis-element-coupling element1 (ABRE-CE1, CCACC) were also found enriched in the MAPS promoters, indicating that JA and ABA signaling likely regulate pollen-specific MAPS expression. This study describes a robust and straightforward pipeline to discover pollen-specific promotes from publicly available data while providing maize breeders and the maize industry a number of late-stage (mature) pollen-specific promoters for use in SPT for hybrid breeding and seed production.
Subject(s)
Gene Expression Profiling/methods , Plant Breeding/methods , Pollen/genetics , Transcriptome , Zea mays/genetics , Gene Expression Regulation, Plant , Plant Infertility/genetics , Pollen/metabolism , Promoter Regions, Genetic , Seeds/genetics , Seeds/metabolism , Zea mays/metabolismSubject(s)
Betacoronavirus , Coinfection/epidemiology , Coronavirus Infections/complications , Coronavirus Infections/epidemiology , Pneumonia, Viral/complications , Pneumonia, Viral/epidemiology , Respiratory Tract Infections/virology , Adolescent , Adult , COVID-19 , COVID-19 Testing , China/epidemiology , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Female , Humans , Male , Middle Aged , Multiplex Polymerase Chain Reaction , Pandemics , Pneumonia, Viral/diagnosis , Respiratory Tract Infections/complications , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/epidemiology , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Young AdultABSTRACT
In this study, we report a new immunoassay platform based on yeast surface display technology for detection of autoantibodies involved in autoimmune diseases, e.g., systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). The autoantigens of Ro52/SSA epitope and SmD were chosen to be displayed on the yeast surface with their respective antibodies as the analytes. By using magnetic beads modified with protein G, yeast cells bound with specific target antibody can be captured. The amount of analytes could be determined by counting the number of fluorescent yeast cells captured in a magnetic field. The platform showed promising results in the detection of SLE autoantibodies with high sensitivity and multiplex detection capability over the traditional approaches.
Subject(s)
Autoantibodies/analysis , Autoantibodies/immunology , Enzyme-Linked Immunosorbent Assay/methods , Lupus Erythematosus, Systemic/diagnosis , Sjogren's Syndrome/diagnosis , Antigens, Surface/immunology , Fluorescence , Humans , Lupus Erythematosus, Systemic/immunology , Magnetics , Microspheres , Sjogren's Syndrome/immunology , YeastsABSTRACT
In this study, we report a new immunoassay platform using yeast cell surface display. This method holds promise for very low limit of detection (LOD) and is suitable for 2-Plex antibody recognition. Instead of adopting a conventional enzyme linked immunosorbent assay (ELISA) protocol by detecting the enzymatic activities or other physicochemical properties of the labeled analytes, this approach determines the quantity of an antibody analyte by directly counting the amount of "modified" yeast cells bound with antibody on the cell surface. c-myc and hemagglutinin (HA) tags were employed as an epitope model to demonstrate our approach. This yeast surface display based cell counting immunoassay (abbreviated as YSD-CCI) for anti-c-myc has a detection limit of 0.2 ng/mL, which is about 80 times higher than that of a conventional yeast ELISA under a similar condition. Moreover, the YSD-CCI's capability for 2-Plex antibody detection was demonstrated by simultaneous detection of anti-c-myc and anti-HA using engineered yeast cells expressing intracellular enhanced green fluorescent protein (EGFP) and mCherry, respectively. This proof-of-concept study paves the way for a new ultrasensitive multiplexed immunoassay method for diagnostic applications.
Subject(s)
Immunoassay/methods , Saccharomyces cerevisiae/metabolism , Antibodies/immunology , Epitopes/immunology , Flow Cytometry , Green Fluorescent Proteins/chemistry , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Hemagglutinins/chemistry , Hemagglutinins/immunology , Lasers , Proto-Oncogene Proteins c-myc/chemistry , Proto-Oncogene Proteins c-myc/immunology , Saccharomyces cerevisiae/geneticsABSTRACT
In order to obtain an ultra-sensitive molecular biosensor, we designed an auto-biotinylated bifunctional protein nanowire (bFPNw) based on the self-assembly of a yeast amyloid protein, Sup35, to which protein G and a biotin acceptor peptide (BAP) were genetically fused. These auto-biotinylated bFPNws can transfer hundreds of commercially available diagnostic enzymes to an antigen-antibody complex via the biotin-avidin system, greatly enhancing the sensitivity of immune-biosensing. Compared to our previously reported seeding-induced bFPNws (Men et al., 2009), these auto-biotinylated bFPNws gave greater signal amplification, reduced non-specific binding and improved stability. The auto-biotinylated self-assembled bFPNw molecular biosensors were applied to detect Yersinia pestis (Y. pestis) F1 antigen and showed a 2000- to 4000-fold increase in sensitivity compared to traditional immunoassays, demonstrating the potential use of these self-assembling protein nanowires in biosensing.
Subject(s)
Biosensing Techniques/instrumentation , Immunoassay/instrumentation , Nanowires/chemistry , Antigens, Bacterial/analysis , Awards and Prizes , Bacterial Proteins/analysis , Bacterial Proteins/chemistry , Biosensing Techniques/methods , Biosensing Techniques/statistics & numerical data , Biotinylation , Cross-Linking Reagents/chemistry , Immunoassay/methods , Immunoassay/statistics & numerical data , Nanowires/ultrastructure , Peptide Termination Factors/chemistry , Peptide Termination Factors/ultrastructure , Protein Multimerization , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/ultrastructure , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/ultrastructure , Yersinia pestis/immunologyABSTRACT
Alkaline phosphatases (APs), known inducible enzymes of the Pho regulon and poorly characterized in cyanobacteria, hydrolyze phosphomonoesters to produce inorganic phosphate (P(i)) during P(i) starvation. In this study, two predicted alkaline phosphatase genes in the genome of Anabaena sp. PCC 7120, all2843 and alr5291, were apparently induced during P(i) starvation. Sequence analysis showed that alr5291 encodes a protein that is an atypical alkaline phosphatase like other cyanobacteria PhoAs, but the protein encoded by all2843 is very similar to the classical PhoAs, such as Escherichia coli alkaline phosphatase (EAP). To date, there have been no reports about classical phoA in cyanobacterial genomes. The alkaline phosphatase AP(A), coded by all2843, is characterized as a metalloenzyme containing Mg2+ and Zn2+ with molar ratio of 1 : 2. Site-directed mutagenesis analysis indicated that, though the active center of AP(A) is highly conserved in comparison with EAP, differences do exist between AP(A) and EAP in metal ion coordination. Besides, biochemical analysis revealed that AP(A) is a monomeric protein and inactivated rapidly at 50 degrees C. These results suggest that AP(A) is the first monomeric heat-labile classical PhoA found in cyanobacteria.
Subject(s)
Alkaline Phosphatase/chemistry , Anabaena/enzymology , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Amino Acid Sequence , Anabaena/classification , Catalytic Domain , Hydrogen-Ion Concentration , Kinetics , Metals/chemistry , Molecular Sequence Data , Mutagenesis, Site-Directed , Phosphates/pharmacology , Phylogeny , Sequence Alignment , TemperatureABSTRACT
A thermophilic esterase, SsoPEst, from Sulfolobus solfataricus P2 was cloned and expressed in E. coli AD494 (DE3). Gene sequencing indicated the encoded 353 amino acids had less than 32% identity with reported esterases. The recombinant enzyme hydrolyzed p-nitrophenyl esters but not tributyrin or tricaprylin, exhibiting the highest specific activity (1.1 U/mg) with p-nitrophenyl caprylate. The enzyme was optimally active at pH 5.5 and 80 degrees C. It retained 50% activity after 1 h incubation at 80 degrees C. Activity was significantly inhibited by PMSF. Five SsoPEst mutants were generated by site-directed mutagenesis. One mutant had a higher specific activity of 2.8 U/mg at 37 degrees C and 14 U/mg at 80 degrees C than the wild-type enzyme which exhibited 0.7 U/mg at 37 degrees C and 3.8 U/mg at 80 degrees C against p-nitrophenyl butyrate.
Subject(s)
Esterases/genetics , Esterases/metabolism , Sulfolobus solfataricus/enzymology , Sulfolobus solfataricus/genetics , Amino Acid Sequence , Binding Sites , Cloning, Molecular , Enzyme Stability , Esterases/chemistry , Hydrogen-Ion Concentration , Models, Molecular , Molecular Sequence Data , Mutation , Sequence Alignment , TemperatureABSTRACT
A phage display-based bifunctional display system was developed for simple and sensitive immunoassay. The resulting bifunctional phage could simultaneously display a few single-chain variable fragment (ScFv) and many copies of the gold-binding peptide on its surface, thereby mediating antigen recognition and signal amplification. As a demonstration study, it was possible for bifunctional phage-based immunoassay to identify Bacillus anthracis spores from other Bacillus strains with detection sensitivity 10-fold higher than that of conventional phage enzyme-linked immunosorbent assay (ELISA). This protocol may be applied to build other bifunctional phage clones for broad applications (e.g., immunoassay kits, affinity biosensors, biorecognition assays).
Subject(s)
Bacillus anthracis/isolation & purification , Immunoassay/methods , Peptide Library , Metal Nanoparticles/ultrastructure , Peptides/metabolism , Spores, Bacterial/isolation & purificationABSTRACT
AIM: To investigate the relationship among histamine, tryptase and beta-hexosaminidase in the process of mast cell release and search for the suitable index to describe mast cell degranulation. METHODS: Mast cell degranulation was performed in vitro, in which histamine, tryptase and beta-hexosaminidase are detected by spectrophotometry. RESULTS: The concordance was found to exit among the three mediums, furthermore the study discloses that more similarity was found between tryptase and beta-hexosaminidase. Histamine was difficult and inconstant to be detected. CONCLUSION: Tryptase and beta-hexosaminidase are more suitable and accurately to reflect mast cell degranulation in vitro than histamine. Tryptase is the excellent index to detect mast cell degranulation in vitro.
Subject(s)
Histamine , Tryptases , Cell Degranulation , Histamine Release , Humans , Mast Cells/immunology , Serine Endopeptidases , beta-N-AcetylhexosaminidasesABSTRACT
A functionalized gold nanoparticle (GNP) enhanced ultrasensitive immuno-PCR assay (GNP-IPCR on ELISA plate), which was modified from the recent developed bio-barcode assay (BCA) technique, was developed to detect Hantaan virus nucleocapsid protein (HNP). During the assay, the target antigen HNP was captured by a polyclonal antibody coated on ELISA microplate wells, followed by adding GNP dually modified with oligonucleotides and a HNP specific monoclonal antibody L13 (mAb L13) to form a sandwich immuno-complex. The oligonucleotides on the GNP contained two strands: one as capture DNA immobilized on the surface of the GNP through Au-S bond and the other as signal amplification DNA, which was partially complementary with the capture DNA. After the immuno-complex was formed, the signal DNA was released by heating, and consequently characterized by PCR/gel electrophoresis and SYBR-Green real time PCR. The detection limit of this method could reach down to 10 fg/mL for detecting purified HNP in buffers as well as in human serum, which was approximately 7 orders of magnitude more sensitive than that of conventional ELISA. The current assay format might be adopted for other proteins that need ultra-high sensitive detection.
Subject(s)
Antigens, Viral/blood , Capsid Proteins/blood , Enzyme-Linked Immunosorbent Assay , Gold , Hantaan virus/metabolism , Hantavirus Infections/diagnosis , Metal Nanoparticles , Molecular Probe Techniques , Polymerase Chain Reaction , Viral Core Proteins/blood , Hantavirus Infections/virology , Humans , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
Aiming to build a supersensitive and easily operable immunoassay, bifunctional protein nanowires were generated by seeding-induced self-assembling of the yeast amyloid protein Sup35p that genetically fused with protein G and an enzyme (methyl-parathion hydrolase, MPH), respectively. The protein nanowires possessed a high ratio of enzyme molecules to protein G, allowing a dramatic increase of the enzymatic signal when protein G was bound to an antibody target. As a result, a 100-fold enhancement of the sensitivity was obtained when applied in the detection of the Yersinia pestis F1 antigen.
Subject(s)
Enzyme-Linked Immunosorbent Assay , Nanowires/chemistry , Bacterial Proteins/analysis , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/genetics , Peptide Termination Factors/chemistry , Peptide Termination Factors/genetics , Phosphoric Monoester Hydrolases/chemistry , Phosphoric Monoester Hydrolases/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/genetics , Sensitivity and SpecificityABSTRACT
Food allergy is a major health issue worldwide. Mast cells play a very important role in the immediate hypersensitivity for which mast cell degranulation needs to be studied extensively. In this study, an approach was taken to study the characteristics of sensitized mast cell degranulation in vitro, which associated with the study of mast cells and animal models. BALB/c mice were immunized respectively by several food allergens, then blood and peritoneal mast cells were collected at different time points. A dynamic determination was carried out between mast cells and serumal IgE. Comparative analysis on sequential time points showed that there was a close coincidence between mast cell degranulation and IgE antibody titers in sensitized BALB/c mice. Furthermore, it is interesting that sensitized mast cells could implement specific degranulation against the challenges in vitro, but the closely tropomyosins induced mast cell degranulation displayed cross reactions. This is very similar to IgE resisting the allergens in vivo. The study disclosed some characteristics on mast cells, coming from sensitized BALB/c mice, degranulation in vitro.
Subject(s)
Allergens/immunology , Food Hypersensitivity/immunology , Immunoglobulin E/blood , Mast Cells/metabolism , Tropomyosin/immunology , Animals , Cell Degranulation , Chickens , Cross Reactions/immunology , Eggs , Epitopes , Food Hypersensitivity/pathology , Food Hypersensitivity/physiopathology , Immunization , Mast Cells/immunology , Mast Cells/pathology , Mice , Mice, Inbred BALB C , Milk , Molecular Mimicry , Penaeidae , Peritoneum/pathology , Shellfish , Time FactorsABSTRACT
Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sargassum graminifolium turn (SG), Sargassum thunbergii (STH), and Laminaria japonica (LJ) from China. The ethanol extracts of these brown seaweeds were optimized at 85% (v/v) ethanol for the maximum yield of phlorotannin, an inhibitor against hyaluronidase. Total phlorotannins contained in the crude extracts were measured as 1.71% (SG), 0.74% (STH), 0.97% (LJ), 3.30% (SC), and 5.06% (ST). The 50% inhibitory concentrations (IC(50)) of Pakistani SC and ST were 109.5 and 21 microg/ml, respectively, lower than those of Chinese SG, STH, and LJ (134, 269, and 148 microg/ml, respectively). An antiallergic drug, disodium cromoglycate (DSCG), had an IC(50)=39 microg/ml, and a natural inhibitor of hyaluronidase, catechin, had an IC(50)=20 microg/ml. The IC(50) of ST extract was found similar to that of catechin (21 vs 20 microg/ml) and lower than that of DSCG (21 vs 39 microg/ml). This suggests that ST is a potent inhibitor of hyaluronidase, indicating a promising future development of natural antiallergic medicines or functional foods.