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1.
Pediatr Res ; 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38438553

ABSTRACT

BACKGROUND: To facilitate the identification of less common clinical phenotypes of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in children. METHODS: We retrospectively reviewed medical records of 236 patients with MOGAD. The following phenotypes were considered to be typical for MOGAD: ADEM, ON, TM, and NMOSD. Less common onset clinical phenotypes were screened out; their clinical and magnetic resonance imaging (MRI), diagnosis, treatment, and prognosis were summarized and analyzed. RESULTS: 16 cases (6.8%) presented as cortical encephalitis, with convulsions, headache, and fever as the main symptoms. 15 cases were misdiagnosed in the early period. 13 cases (5.5%) showed the overlapping syndrome of MOGAD and anti-N-methyl-D aspartate receptor encephalitis (MNOS), with seizures (92.3%) being the most common clinical symptom. 11 cases (84.6%) showed relapses. The cerebral leukodystrophy-like phenotype was present in seven cases (3.0%), with a recurrence rate of 50%. Isolated seizures without any findings on MRI phenotype was present in three cases (1.3%), with the only clinical symptom being seizures of focal origin. Three cases (1.3%) of aseptic meningitis phenotype presented with prolonged fever. CONCLUSION: 40/236 (16.9%) of children with MOGAD had less common phenotypes. Less common clinical phenotypes of pediatric MOGAD are susceptible to misdiagnosis and deserve more attention. IMPACT: This is the first comprehensive analysis and summary of all less commonl clinical phenotypes of MOGAD in children, while previous studies have only focused on a specific phenotype or case reports. We analyzed the characteristics of MOGAD in children and further revealed the reasons why these less common clinical phenotypes are prone to misdiagnosis and deserve more attention. Our research on treatment has shown that early detection of MOG antibodies and early treatment are of great significance for improving the prognosis of these patients.

2.
Front Pharmacol ; 13: 974216, 2022.
Article in English | MEDLINE | ID: mdl-36210813

ABSTRACT

Background: The florets of Carthamus tinctorius L. (Safflower) is an important traditional medicine for promoting blood circulation and removing blood stasis. However, its bioactive compounds and mechanism of action need further clarification. Objective: This study aims to investigate the effect and possible mechanism of 6-hydroxykaempferol 3,6-di-O-glucoside-7-O-glucuronide (HGG) from Safflower on endothelial injury in vitro, and to verify its anti-thrombotic activity in vivo. Methods: The endothelial injury on human umbilical vein endothelial cells (HUVECs) was induced by oxygen-glucose deprivation followed by reoxygenation (OGD/R). The effect of HGG on the proliferation of HUVECs under OGD/R was evaluated by MTT, LDH release, Hoechst-33342 staining, and Annexin V-FITC apoptosis assay. RNA-seq, RT-qPCR, Enzyme-linked immunosorbent assay and Western blot experiments were performed to uncover the molecular mechanism. The anti-thrombotic effect of HGG in vivo was evaluated using phenylhydrazine (PHZ)-induced zebrafish thrombosis model. Results: HGG significantly protected OGD/R induced endothelial injury, and decreased HUVECs apoptosis by regulating expressions of hypoxia inducible factor-1 alpha (HIF-1α) and nuclear factor kappa B (NF-κB) at both transcriptome and protein levels. Moreover, HGG reversed the mRNA expression of pro-inflammatory cytokines including IL-1ß, IL-6, and TNF-α, and reduced the release of IL-6 after OGD/R. In addition, HGG exhibited protective effects against PHZ-induced zebrafish thrombosis and improved blood circulation. Conclusion: HGG regulates the expression of HIF-1α and NF-κB, protects OGD/R induced endothelial dysfunction in vitro and has anti-thrombotic activity in PHZ-induced thrombosis in vivo.

3.
J Food Sci ; 87(11): 4905-4916, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36303405

ABSTRACT

The flavan-3-ols of 10 primarily plant food byproducts, including Muscat Hamburg grape seed, hawthorn sarcocarp, litchi pericarp, cocoa bean, peanut skin, lotus seedpod, Xinyang Maojian green tea, Cinnamomi cortex, Sargentodoxa cuneata stem, and Cyperus esculentus, leaves were analyzed. Ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry was used for the analysis. Cyperus esculentus leaves contained a high amount of procyanidin B1 (198.9 mg/100 g), second only to Muscat Hamburg grape seed (292.9 mg/100 g). Unlike grape seed that contained several procyanidin B isomers with very similar retention times, C. esculentus leaves contained primarily procyanidin B1 with few isomers. Procyanidin B1 was enriched in the ethyl acetate fraction of a 70% methanol extract of C. esculentus leaves and purified at 95% purity by two runs of open column chromatography. Direct chromatography of the plant extract on octadecylsilane and Sephadex LH20 open columns improved the yield of the resultant leaf procyanidin B1 (95% purity) to 0.21‰. The present research demonstrated that the leaves of C. esculentus, byproducts of tigernut, are ideal plant sources for isolating and providing high-purity procyanidin B1. PRACTICAL APPLICATION: Procyanidin B1 has a broad range of health benefits. Cyperus esculentus is cultivated in many countries with nearly 6190 square hectares (hm2 ) in the Spanish Mediterranean region in 2020-2021 and over 16,700 hm2 in China in recent years, primarily for its tubers. The byproducts, the leaves of C. esculentus, contain high levels of procyanidin B1, with few isomers that interfere with its isolation and purification. Thus, the leaves of this plant provide a viable source for preparing high-purity procyanidin B1.


Subject(s)
Crataegus , Cyperus , Cyperus/chemistry , Plant Extracts/chemistry , Antioxidants
4.
Comput Math Methods Med ; 2022: 5417753, 2022.
Article in English | MEDLINE | ID: mdl-35903433

ABSTRACT

Objective: A case-control study was conducted to explore the efficacy of cohort study and value of CT perfusion imaging in patients with metastatic osteosarcoma after chemotherapy. Methods: Eighty patients with metastatic osteosarcoma treated in our hospital from March 2020 to December 2021 were divided into two groups. According to their different treatment methods, the chemotherapy+antiangiogenesis group had 36 cases and the chemotherapy group had 44 cases. All patients were scanned by 64-slice spiral CT before and after treatment. The differences of tumor volume and perfusion parameters before and after treatment were compared, and the correlation between perfusion parameters and tumor microvessel density (MVD) was analyzed. The receiver working curve (ROC curve) was used to evaluate the efficacy of the two groups after chemotherapy. Results: Blood flow (BF), blood volume (BV), Pallak blood volume (PBV), and time to start (TTS) in the antitumor angiogenesis+chemotherapy group were significantly lower than those before treatment (P < 0.05). Microvessel density was positively correlated with PS, BF, BV, and PBV (P < 0.05). The reduction rate of BV and BF in the remission group after treatment was significantly higher than that in the nonremission group. When the BV and BF decline rates were 47.37% and 21.53% and the areas under the curve were 0.968 and 0.916, respectively, the diagnostic effect was the best. When the decrease rate of BV was 47.48% and the decrease rate of BF was 21.55%, the sensitivity was 94.72% and 89.56% and the specificity was 91.31% and 91.31%. Conclusion: The reduction rate of BV and BF in CT perfusion imaging is of high value in evaluating the efficacy of radiotherapy and chemotherapy in patients with NSCLC and can provide more objective basis for observing the changes and judging the prognosis of osteosarcoma after treatment.


Subject(s)
Lung Neoplasms , Osteosarcoma , Case-Control Studies , Cohort Studies , Humans , Lung Neoplasms/pathology , Osteosarcoma/diagnostic imaging , Osteosarcoma/drug therapy , Perfusion Imaging/methods , Tomography, X-Ray Computed/methods
5.
Seizure ; 99: 105-112, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35636157

ABSTRACT

BACKGROUND: We aimed to study seizure characteristics during the acute phase of Japanese encephalitis (JE) in children, determine the risk factors of postencephalitic epilepsy (PEE), establish a risk prediction model for the disease, and construct a nomogram to visualize the model. METHODS: We retrospectively analyzed the clinical data and follow-up results of 328 children with JE who were hospitalized between January 2011 and December 2020. Risk factors were screened using univariable analysis, a predictive model was built using binary logistic analysis, lasso regression was used for variable screening, and a nomogram was developed. RESULTS: Of the 328 children with JE enrolled in the study, 216 (65.9%, 216/328) had seizures in the acute phase. The incidence of PEE was 14.7% (39/264), The cumulative percentages of PEE after discharge was 10.6% (28/264)at 6 months, which increased to 13.6%(36/264)at 3 years. 38.5% of patients with PEE had generalized onset seizures, and 17.9% had focal motor seizures. Univariable analysis revealed that 22 clinical indicators were related to the PPE; Multivariable analysis identified seizure number >5 (OR (95%CI) = 3.013 (1.046-8.676), P = 0.041), status epilepticus (OR (95%CI) = 3.918 (1.212-12.669), P = 0.023), and Coma (OR (95%CI) = 22.495 (8.686-58.285), P<0.001) as independent risk factors for PEE. The risk prediction model: ln(p/1p)= -3.533 + 1.103 × (seizures number > 5) +1.366 × (status epilepticus) + 3.113 × (Coma) was developed, and a nomogram was constructed. The area under the ROC curve (AUC), calibration plot, and Hosmer-Lemeshow test showed that the model had good discrimination and calibration. Ordinary bootstrapping was used for internal validation, and the predictive results of the original and test sets were consistent. CONCLUSIONS: Seizure is a common manifestation during acute encephalitis and sequelae in children with JE. The nomogram constructed in this study could be used for early prediction, and could facilitate early intervention.


Subject(s)
Encephalitis, Japanese , Epilepsy , Status Epilepticus , Child , Coma , Encephalitis, Japanese/complications , Encephalitis, Japanese/epidemiology , Epilepsy/diagnosis , Epilepsy/epidemiology , Epilepsy/etiology , Humans , Retrospective Studies , Risk Factors , Seizures/complications , Status Epilepticus/etiology
6.
Front Pediatr ; 9: 676616, 2021.
Article in English | MEDLINE | ID: mdl-34041212

ABSTRACT

Objectives: To study the genetic and clinical characteristics of Chinese children with pathogenic proline-rich transmembrane protein 2 (PRRT2) gene-associated disorders. Methods: Targeted next generation sequencing (NGS) was used to identify pathogenic PRRT2 variations in Chinese children with epilepsy and/or kinesigenic dyskinesia. Patients with confirmed PRRT2-associated disorders were monitored and their clinical data were analyzed. Results: Forty-four patients with pathogenic PRRT2 variants were recruited. Thirty-five of them (79.5%) had heterozygous mutations, including 30 frameshifts, three missenses, one nonsense, and one splice site variant. The c.649dupC was the most common variant (56.8%). Eight patients (18.2%) showed whole gene deletions, and one patient (2.3%) had 16p11.2 microdeletion. Thirty-four cases (97.1%) were inherited and one case (2.9%) was de novo. Forty patients were diagnosed with benign familial infantile epilepsy (BFIE), two patients had paroxysmal kinesigenic dyskinesia (PKD) and two had infantile convulsions and choreoathetosis (ICCA). Patients with whole gene deletions had a later remission than patients with heterozygous mutations (13.9 vs. 7.1 months, P = 0.001). Forty-two patients were treated with antiseizure medications (ASMs). At last follow-up, 35 patients, including one who did not receive therapy, were asymptomatic, and one patient without ASMs died of status epilepticus at 12 months of age. One patient developed autism, and one patient showed mild developmental delay/intellectual disability. Conclusion: Our data suggested that patients with whole gene deletions could have more severe manifestations in PRRT2-associated disorders. Conventional ASMs, especially Oxcarbazepine, showed a good treatment response.

7.
Front Pediatr ; 8: 574803, 2020.
Article in English | MEDLINE | ID: mdl-33240831

ABSTRACT

Objective: This study aims to analyze the electroclinical characteristics and gene test results of children on the severe end of the epilepsy aphasia spectrum (EAS) and also the correlation of EAS-related GRIN2A genes to explore the genotype-phenotype relationships, as well as potential pathogenic mechanism of EAS. Methods: A retrospective study was conducted on the participants diagnosed with Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS), and atypical benign partial epilepsy (ABPE) at the Children's Hospital of Chongqing Medical University from January 2013 to June 2019. Whole-exome sequencing was performed in six patients, and epileptic panel was carried out in two. In addition, we reviewed all the published literatures reporting EAS patients with pathogenic variants until June 2019 and conducted Gene Ontology (GO) analysis, as well as protein-protein interaction (PPI) network. Results: The mean age at seizure onset was 55.4 ± 27.0 months. The baseline severity of the spike-wave index (SWI) was not significantly correlated with intellectual disability (ID) level. Two pathogenic de novo GRIN2A null variants were identified in patients with ABPE who had less severe ID, despite the electrical status epilepticus during slow-wave sleep (ESES). By literature reviewing, 18 GRIN2A missense mutations and 11 GRIN2A truncating mutations which lead to N-methyl-d-aspartate receptors' loss of function has been reported. Of these mutations, 9 (31.0%) are situated in amino (N)-terminal domain, 6 (20.7%) in linger-binding domain S1, and 10 (34.5%) in linger-binding domain S2. EAS-related genes were enriched in the biological process of chemical synaptic transmission and vocalization (FDR, <0.01). The hub protein in PPI network is GluN2A, which might affect language function via foxp2-srpx2/uPAR signal network. Conclusion: Our data suggested that when children suspected with benign epilepsy of children with centrotemporal spikes (BECTs) have early-onset age, changed seizure semiology, and deterioration of behavior/cognition/motor function, neurologists should be alert of the appearance of ESES. The neuropsychological deterioration in children with EAS might not only be completely affected by electric discharge severity but also genetic etiology. Our finding also enforced the current genotype-phenotype relationship theory about EAS. For EAS children, GRIN2A-FOXP2-SRPX2/uPAR signal network might contribute to the mechanism of their language deficit.

8.
Exp Ther Med ; 16(3): 2087-2093, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30186444

ABSTRACT

The aim of the current study was to discuss and analyze computerized tomography (CT) features and clinicopathological characteristics of patients with Kimura disease in head and neck. CT and clinicopathological data of 12 patients with Kimura disease diagnosed between May 2011 and May 2015 were analyzed. The mean age was 43.9 years and the disease course varied from 1 week-20 years. The mean absolute value of eosinophil granulocytes was 1.95×109/l. Multiple nodules were detected in 4 patients with Kimura disease. Main symptoms included multiple enlarged lymph nodes in neck and submaxillary regions. CT imaging of nodular lesions revealed a clear boundary, with moderate to marked homogeneous enhancement. Diffuse mass lesions were observed in 6 patients with Kimura disease. Main symptoms included subcutaneous diffuse soft tissue mass in parotid gland and maxillofacial regions. CT imaging of diffuse mass revealed unclear boundaries, adjacent skin thickness and moderate heterogeneous enhancement. In some cases, the diffuse mass involved soft mass with unclear boundaries. Pathological symptoms of Kimura disease included infiltration of eosinophilia, lymphocytic proliferation, formation of lymphatic follicles and variable degrees of fibrosis and vascular proliferation. Diagnosis of Kimura disease in head and neck regions may be improved based on lesions with clear or unclear boundaries, homogeneous or heterogeneous enhancement, with or without lymphadenectasis and by the presence of peripheral blood eosinophilia. However, a final diagnosis relies on a pathological examination.

9.
Zhongguo Dang Dai Er Ke Za Zhi ; 18(7): 573-6, 2016 Jul.
Article in Chinese | MEDLINE | ID: mdl-27412536

ABSTRACT

OBJECTIVE: To investigate the differences in clinical features of childhood purulent meningitis (PM) caused by Escherichia coli and Streptococcus pneumoniae, and to provide help for the selection of antibiotics for PM children with unknown etiology. METHODS: A retrospective analysis was performed for the clinical data of children with PM caused by Escherichia coli (12 children) or Streptococcus pneumoniae (15 children). RESULTS: Compared with the Streptococcus pneumoniae infection group, the Escherichia coli infection group had a significantly higher proportion of children with an age of onset of <3 months and a significantly higher incidence rate of convulsion, but significantly lower incidence rates of severe fever (>39°C) and disturbance of consciousness and a significantly lower proportion of children with an increased leukocyte count at diagnosis (>12×10(9)/L). The results of routine cerebrospinal fluid test and biochemical examinations showed no significant differences between the two groups. Escherichia coli and Streptococcus pneumoniae were resistant to cephalosporins and had a sensitivity to chloramphenicol more than 90%. Escherichia coli was fully sensitive to meropenem and Streptococcus pneumoniae was fully sensitive to vancomycin. CONCLUSIONS: PM caused by Escherichia coli and Streptococcus pneumoniae has different clinical features. As for PM children with severe fever, disturbance of consciousness, and an increased leukocyte count, the probability of Streptococcus pneumoniae infection should be considered. For PM children with an age of onset of <3 months, medium- and low-grade fever, frequent convulsions, and a leukocyte count of <12×10(9)/L, the probability of Escherichia coli infection should be considered.


Subject(s)
Meningitis, Escherichia coli/diagnosis , Meningitis, Pneumococcal/diagnosis , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Meningitis, Escherichia coli/drug therapy , Meningitis, Pneumococcal/drug therapy , Microbial Sensitivity Tests , Retrospective Studies , Suppuration
10.
Chin J Nat Med ; 13(11): 873-880, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26614463

ABSTRACT

The present study was designed to investigate the bioactive constituents of Xanthoceras sorbifolia in terms of amounts and their antioxidant, DNA scission protection, and α-glucosidase inhibitory activities. Simultaneous quantification of 10 X. sorbifolia constituents was carried out by a newly established ultra-high performance liquid chromatography-quadrupole mass spectrometry method (UHPLC-MS). The antioxidant activities were evaluated by measuring DPPH radical scavenging and DNA scission protective activities. The α-glucosidase inhibitory activities were investigated by using an assay with α-glucosidase from Bacillus Stearothermophilus and disaccharidases from mouse intestine. We found that the wood of X. sorbifolia was rich in phenolic compounds with the contents of catechin, epicatechin, myricetin, and dihydromyricetin being 0.12-0.19, 1.94-2.16, 0.77-0.91, and 6.76-7.89 mg·g(-1), respectively. The four constituents strongly scavenged DPPH radicals (with EC50 being 4.2, 3.8 and 5.7 µg·mL(-1), respectively) and remarkably protected peroxyl radical-induced DNA strand scission (92.10%, 94.66%, 75.44% and 89.95% of protection, respectively, at a concentration of 10 µmol·L(-1)). A dimeric flavan 3-ol, epigallocatechin-(4ß→8, 2ß→O-7)-epicatechin potently inhibited α-glucosidase with an IC50 value being as low as 1.2 µg·mL(-1). The established UHPLC-MS method could serve as a quality control tool for X. sorbifolia. In conclusion, the high contents of antioxidant and α-glucosidase inhibitory constituents in X. sorbifolia support its use as complementation of other therapeutic agents for metabolic disorders, such as diabetes and hypertension.


Subject(s)
Antioxidants/pharmacology , DNA Damage , DNA/drug effects , Glycoside Hydrolase Inhibitors/pharmacology , Plant Extracts/pharmacology , Sapindaceae/chemistry , alpha-Glucosidases/metabolism , Antioxidants/analysis , Biphenyl Compounds/metabolism , Catechin/analogs & derivatives , Catechin/analysis , Catechin/pharmacology , Chromatography, High Pressure Liquid , Flavonoids/analysis , Flavonoids/pharmacology , Glycoside Hydrolase Inhibitors/analysis , Mass Spectrometry , Picrates/metabolism , Plant Extracts/chemistry , Triterpenes/analysis , Triterpenes/pharmacology , Wood/chemistry
11.
J Food Sci ; 79(10): C1970-83, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25227714

ABSTRACT

Ten compounds were isolated and purified from the peels of gold-red apple (Malus domestica) for the 1st time. The identified compounds are 3ß, 20ß-dihydroxyursan-28-oic acid (1), 2α-hydroxyoleanolic acid (2), euscaphic acid (3), 3-O-p-coumaroyl tormentic acid (4), ursolic acid (5), 2α-hydroxyursolic acid (6), oleanolic acid (7), betulinic acid (8), linolic acid (9), and α-linolenic acid (10). Their structures were determined by interpreting their nuclear magnetic resonance and mass spectrometry (MS) spectra, and by comparison with literature data. Compound 1 is new, and compound 2 is herein reported for the 1st time for the genus Malus. α-Glucosidase inhibition assay revealed 6 of the triterpenoid isolates as remarkable α-glucosidase inhibitors, with betulinic acid showing the strongest inhibition (IC50 = 15.19 µM). Ultra-performance liquid chromatography-electrospray ionization MS analysis of the fruit peels, pomace, flesh, and juice revealed that the peels and pomace contained high levels of triterpenes, suggesting that wastes from the fruit juice industry could serve as rich sources of bioactive triterpenes.


Subject(s)
Fruit/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Malus/chemistry , alpha-Glucosidases/metabolism , Glycoside Hydrolase Inhibitors/chemistry , Magnetic Resonance Spectroscopy , Oleanolic Acid/analogs & derivatives , Pentacyclic Triterpenes , Spectrometry, Mass, Electrospray Ionization , Triterpenes , alpha-Linolenic Acid/analysis , Betulinic Acid , Ursolic Acid
12.
J Food Sci ; 77(10): C1097-102, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22938385

ABSTRACT

UNLABELLED: The apple-shaped pear, the fruit of the Pyrus pyrifolia cv. pingguoli (Rosaceae) tree, is one of the most popular fruits in the northern part of China. The current study is the 1st report of its bioactive components. We identified 10 metabolites from the peels (exocarp) of apple-shaped pear and assessed their toxicity. We then compared the anti-oxidant activity, amount of total phenolic compounds, and total condensed tannin content of the peels and flesh (mesocarp) of apple-shaped pear. The 6 major components in the peels and flesh of this fruit were quantified with Ultra Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry. Results revealed that the peels possessed stronger anti-oxidant activity and contained larger amounts of phenolic compounds than the flesh. These results provide insights into the potential health benefits of this fruit and support the use of the fruit peels and products containing peels or peel components. PRACTICAL APPLICATION: The present research provided evidences that the pulp and peel waste from the juice industry of apple-shaped pear may be a source of useful compounds.


Subject(s)
Antioxidants/analysis , Fruit/chemistry , Pyrus/chemistry , Beverages/analysis , China , Phenols/analysis , Plant Extracts/analysis , Spectrometry, Mass, Electrospray Ionization , Tannins/analysis
13.
Food Chem ; 135(4): 2425-9, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-22980823

ABSTRACT

Eleven compounds were isolated from potato peels and identified. Their structures were determined by interpretation of UV, MS, 1D, and 2D NMR spectral data and by comparison with reported data. The main components of the potato peels were found to be chlorogenic acid and other phenolic compounds, accompanied by 2 glycoalkaloids, 3 low-molecular-weight amide compounds, and 2 unsaturated fatty acids, including an omega-3 fatty acid. The potato peels showed more potent radical scavenging activity than the flesh. The quantification of the 11 components indicated that the potato peels contained a higher amount of phenolic compounds than the flesh. These results suggest that peel waste from the industry of potato chips and fries may be a source of useful compounds for human health.


Subject(s)
Alkaloids/chemistry , Amides/chemistry , Fatty Acids, Unsaturated/chemistry , Phenols/chemistry , Plant Extracts/chemistry , Plant Tubers/chemistry , Solanum tuberosum/chemistry , Alkaloids/isolation & purification , Amides/isolation & purification , Fatty Acids, Unsaturated/isolation & purification , Molecular Structure , Phenols/isolation & purification , Plant Extracts/isolation & purification
14.
J Gen Virol ; 93(Pt 1): 50-60, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21940411

ABSTRACT

West Nile virus (WNV) non-structural protein 1 (NS1) elicits protective immune responses during infection of animals. WNV NS1-specific antibody responses can provide the basis for serological diagnostic reagents, so the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the conservation of these sites among the Japanese encephalitis virus (JEV) serocomplex members also needs to be defined. The present study describes the mapping of linear B-cell epitopes in WNV NS1. We screened eight NS1-specific mAbs and antisera (polyclonal antibodies; pAbs) from mice immunized with recombinant NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. The screen using mAbs identified four WNV-specific (including Kunjin virus) epitopes, located at aa 21-36, 101-116, 191-206 and 261-276 in WNV NS1. However, using pAbs, only three WNV-specific epitopes were identified, located at positions 101-116, 191-206 and 231-246. Two of these epitopes (aa 21-36 and 261-276) had different reactivity with mAbs and pAbs. The knowledge and reagents generated in this study have potential applications in differential diagnostics and epitope-based marker vaccine development for WNV and viruses of the JEV serocomplex.


Subject(s)
Encephalitis Virus, Japanese/immunology , Encephalitis, Japanese/virology , Epitope Mapping , Epitopes, B-Lymphocyte/immunology , Viral Nonstructural Proteins/immunology , West Nile Fever/virology , West Nile virus/immunology , Amino Acid Sequence , Animals , Antibodies, Viral/immunology , Cell Line , Encephalitis Virus, Japanese/chemistry , Encephalitis Virus, Japanese/genetics , Encephalitis, Japanese/immunology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/genetics , Female , Humans , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Sequence Alignment , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , West Nile Fever/immunology , West Nile virus/chemistry , West Nile virus/genetics
15.
BMC Microbiol ; 11: 160, 2011 Jul 06.
Article in English | MEDLINE | ID: mdl-21729328

ABSTRACT

BACKGROUND: The West Nile virus (WNV) nonstructural protein 1 (NS1) is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified. RESULTS: The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs) 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 ((895)LTATTEK(901) and (925)VVDGPETKEC(934)). Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that (896)TATTEK(901) and (925)VVDGPETKEC(934) are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV) serocomplex. CONCLUSIONS: We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.


Subject(s)
Epitopes, B-Lymphocyte/immunology , Peptide Library , Viral Nonstructural Proteins/immunology , West Nile virus/immunology , Animals , Antibodies, Monoclonal/isolation & purification , Antibodies, Viral/blood , Blotting, Western , Epitopes, B-Lymphocyte/genetics , Horse Diseases/immunology , Horses , Mass Screening , Mice , Mice, Inbred BALB C , Viral Nonstructural Proteins/genetics , West Nile Fever/immunology , West Nile Fever/veterinary , West Nile virus/genetics
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