[Identification of genotype III Japanese encephalitis virus isolated in Zhejiang province].

OBJECTIVE: To investigate the molecular characteristics and genotype of Japanese encephalitis virus (JEV) found in vector mosquitoes in Zhejiang province from 1982 to 1983. METHODS: A total of 3188 mosquitoes were collected in Dinghai district and Yiwu city in Zhejiang province, during year 1982 and 1983. The virus was isolated by C6/36 cell, and then identified by hemagglutination inhibition test. The isolated strains were activated in year 2011, and plaque forming unit (PFU) were applied to test the virus titer. The suckling rats were tested under intracranial inoculation, where PrM and E genes were amplified and sequenced. Their nucleotide and amino acid sequences were analyzed and compared with the JEV vaccine strain SA14-14-2 and the JEV isolated in Zhejiang province during 2007 and 2010; and phylogenetic tree were constructed by bioinformatic software. RESULTS: From the 3188 mosquitoes captured, eleven virus strains were isolated and found to be able to cause cytopathogenic effect (CPE) in C6/36 cells within 72 hours. Virus titer ranged from 2.5 to 6.47 lg PFU/ml. The suckling rats would die within 72 hours since the inoculation. The phylogenetic analysis with the PrM and E genes showed that the JEV isolated in Zhejiang during 1982 and 1983 belonged to genotype III; while the JEV isolated in Zhejiang during 2007 and 2010 belonged to genotype I. The analysis of E genes from 5 isolated strains found that the homology of nucleotide sequence was over 98.9%, and the homology of amino acid sequence was over 99.8%. The compare between the 5 virus strains and the vaccine strain SA14-14-2 found 10 common amino acid variation sites, and showed that the homology of nucleotide sequence was over 97.7%, and the homology of amino acid sequence was 99.2%. The compare between the 5 virus strains and the JEV isolated in Zhejiang during 2007 and 2010 found a 87.7% - 87.9% nucleotide homology and an over 98.8% amino acid homology. CONCLUSION: The JEV isolated from the mosquitoes in Dinghai district and Yiwu city between year 1982 and 1983, were genotype III.

Association of IGF1R polymorphisms (rs1546713) with susceptibility to age-related cataract in a Han Chinese population.

AIM: To explore the susceptible association between the insulin-like growth factor-1 receptor (IGF1R) single nucleotide polymorphism (SNP) and age-related cataract (ARC), and investigate the underlying mechanisms in human lens epithelium (HLE) cells. METHODS: Totally 1190 unrelated participants, comprising 690 ARC patients and 500 healthy individuals in Han Chinese population were recruited and genotyped for target SNP. The χ 2-test was used to detect genotypic distribution between the patient and control groups and the logistic regression was performed to adjust the age and gender. Meanwhile, different biological experimental methods, such as cell counting kit 8 (CCK-8) assay, flow cytometry, quantitative real time polymerase chain reaction (Q-PCR) and Western blot, were used to detect cell viability, cell cycle progression and apoptosis in HLE cells or IGF1R knockdown HLE cells. RESULTS: The rs1546713 in IGF1R gene was identified (P=0.046, OR: 1.606, 95%CI: 1.245-2.071), which shown a significant relevance with ARC risk under the dominant model. The results demonstrated that IGF1R knockdown inhibited cell proliferation by inducing cell cycle arrested at S phase and promoting apoptosis. Mechanistically, the cell cycle blocked at S phase was linked with the alterations of cyclin A, cyclin B, cyclin E and P21. The pro-apoptosis function of IGF1R may related with stimulating the activation of Caspase-3 and altering the expression levels of apoptotic proteins, including Bcl-2, Bax and Caspase-3. CONCLUSION: This study first report that IGF1R polymorphisms may affect susceptibility to ARCs in Han Chinese population and provide new clues to understand the pathogenic mechanism of ARCs. Notably, IGF1R is likely a potential target for ARC prevention and treatment.

Sero-Molecular Epidemiology of Japanese Encephalitis in Zhejiang, an Eastern Province of China.

BACKGROUND: Sporadic Japanese encephalitis (JE) cases still have been reported in Zhejiang Province in recent years, and concerns about vaccine cross-protection and population-level immunity have been raised off and on within the public health sphere. Genotype I (GI) has replaced GIII as the dominant genotype in Asian countries during the past few decades, which caused considerable concerns about the potential change of epidemiology characteristics and the vaccine effectiveness. The aim of this study was to investigate the prevalence of JE neutralizing antibody and its waning antibody trend after live attenuated JE vaccine immunization. Additionally, this study analyzed the molecular characteristics of the E gene of Zhejiang Japanese encephalitis virus (JEV) strains, and established genetic relationships with other JEV strains. METHODOLOGY/PRINCIPAL FINDINGS: A total of 570 serum specimens were sampled from community population aged from 0 to 92 years old in Xianju county of Zhejiang Province in 2013-2014. Microseroneutralization test results were analyzed to estimate the population immunity and to observe antibody dynamics in vaccinated children. E genes of 28 JEV strains isolated in Zhejiang Province were sequenced for phylogenetic tree construction and molecular characteristics analysis with other selected strains. Positive JE neutralizing antibody rates were higher in residents ≥35 years old (81%~98%) and lower in residents <35 years old (0~57%). 7 or 8 years after the 2nd live attenuated vaccine dose, the antibodies against for 4 different strains with microseroneutralization test were decreased by 55%~73% on seropositive rates and by 25%~38% on GMTs respectively. JEV strains isolated in recent years were all grouped into GI, while those isolated in the 1980s belonged to GIII. On important amino acid sites related to antigenicity, there was no divergence between the Zhejiang JE virus strains and the vaccine strain (SA14-14-2). CONCLUSION/SIGNIFICANCES: JE neutralizing antibody positive rates increase in age ≥10 years old population, likely reflecting natural infection or natural boosting of immunity through exposure to wild virus. JE seropositivity rates were quite low in <35 years old age groups in Zhejiang Province. Waning of neutralizing antibody after live attenuated vaccine immunization was observed, but the clinical significance should be further investigated. Both the peripheral antibody response and genetic characterization indicate that current live attenuated JE vaccine conferred equal neutralizing potency against GI or GIII of wild strains. GI has replaced GIII as the dominant genotype in Zhejiang in the past few decades. Although the chance of exposure to wild JE virus has reduced, the virus still circulates in nature; therefore, it is necessary to implement immunization program for children continually and to conduct surveillance activity periodically.

[Etiological and molecular-epidemiological analysis on enterovirus associated encephalitis in Zhejiang, 2008-2012].

OBJECTIVE: In order to investigate etiology and molecular-epidemiological characteristics of enterovirus associated encephalitis (EAE) in Zhejiang, 2008-2012. Method Cerebrospinal fluid and stool specimens were collected from suspected EAE patients, who were admitted to our hospitals. RD and Hep-2 cell lines were used to isolate enterovirus (EV). Serotypes of these EV isolates were identified through neutralization test by using serotype specific anti-sera. VP1 genes of these isolates were sequenced, compared and used for the construction of phylogenetic tree. RESULTS: 127 (20.6%) human enterovirus (HEV) strains were isolated from 616 samples, which were collected from 610 patients. Serotypes of these EV isolates, including 60 coxsackievirus (CV), and 67 Echovirus (E)appeared to be CVA9, CVB1, CVB3-5, E3, E4, E6, E9, E14, E25 and E30, respectively. Predominant EV serotypes on EAE from 2008 to 2012 were seen as CVB3, CVB5, E6, E30 and E30, respectively. The full length of VP1 genes from different EV isolates was between 834 and 918 nucleotides. The VP1 gene similarities between these isolates and the reference strains were from 76.7% to 85.0% (nucleotides level) and 91.1% to 97.9% (amino acids level). The VP1 genes from E6 serotype isolates appeared most diverged, reaching 20.4% (nucleotides level) and 4.8% (amino acids level). Based on the generated phylogenetic tree, all the EV isolates were fallen on the same branch of HEV-B, and the isolates in the same serotype formed one sub-branch, suggesting there existed geographical and temporal effects. E6 isolates diverged into two branchlets. CONCLUSION: EVs from HEV-B were the etiologic agents for EAE in Zhejiang province from 2008 to 2012. All these EV isolates showed 12 serotypes, with predominant isolates varied every year. E30 was determined as the most dominant serotype while serotype E6 diverged into two sub-gene types.