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Chen S.,Beijing Institute of Microbiology and Epidemiology
Infection, Genetics and Evolution | Year: 2011

Phylogenetic analysis suggested that the DENV1 strains isolated in the DF outbreak in Guangdong province in 2006 were likely to be imported from Southeast Asian. Specifically, viruses isolated from Shantou and Chaozhou were imported from Singapore; viruses isolated from Guangzhou, Yangjiang, and Foshan were imported from Thailand/Vietnam. Therefore, importation of DENV1 from Southeast Asia was an important contributory factor of the 2006 DF outbreak in Guangdong province. © 2011 Elsevier B.V. Source

Li L.,Beijing Institute of Microbiology and Epidemiology
AIDS research and human retroviruses | Year: 2012

Zhengzhou is the capital of Henan province, where severe HIV prevalence was found in former paid plasma donors. In recent years, the HIV epidemic in men who have sex with men (MSM) increased rapidly in the city. To explore the subtype distribution and genetic characterization of HIV in MSM in Zhengzhou city, phylogenetic analysis was fulfilled based on the full-length gag, pol, and partial env gene. A total of 31 HIV-1-seropositive MSM individuals were enrolled. The full length gag, pol, and partial env gene were amplified and sequenced. Multiple subtypes, including CRF01_AE (45.2%), subtype B (38.7%), and CRF07_BC (16.1%), were identified. Close phylogenetic relationships among our strains with strains from the Henan local area, Hebei MSM population, Beijing area, and Liaoning area were found, suggesting a multiple introduction of HIV into the population. The results will provide clues for prevention and for changes in behavior in the Henan MSM population and also detailed sequence data for vaccine design. Source

Cao R.Y.,Beijing Institute of Microbiology and Epidemiology
Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology | Year: 2011

Enterovirus type 71 (EV71) causes large outbreaks with significant mortality among young children, and no specific antiviral treatment is currently available. Antibody-based therapy represents a promising alternative strategy for lethal EV71 infection. Our previous data has shown that anti-EV71 neutralization antibodies were present in a significant proportion of blood donors in China. To produce a new human intravenous immunoglobulin (IVIG) product containing high titer anti-EV71 neutralizing antibodies and investigate its therapeutic efficacy against lethal EV71 infection in a murine model. Plasma units that contained high titer neutralizing antibodies from selected Chinese donors were pooled and processed into pharmaceutical grade IVIG preparations according to the standard procedure. The efficacy of these EV71-specific IVIG product was characterized in vitro by neutralization assay and in vivo by suckling mouse protection testing. The therapeutic effects against lethal EV71 challenge were further assayed in a suckling mouse model. About 12% of the normal plasma units were selected and pooled to manufacture the EV71-IVIG preparations, and in vitro and in vivo efficacy data showed that these EV71-specific IVIG preparations were enriched with neutralizing antibodies against EV71. Furthermore, treatment with EV71-specific IVIG was evidenced to confer protection against lethal EV71 challenge in a dose- and time-dependent manner in the suckling mouse model. This preclinical study indicates that these "tailor-made" EV71-IVIG preparations manufactured from selected plasma donors in EV71-endemic areas may represent a promising therapeutic option for the lethal EV71 infections, and further clinical trials should be warranted in the future. Copyright © 2011 Elsevier B.V. All rights reserved. Source

Yan Y.,Beijing Institute of Microbiology and Epidemiology
PloS one | Year: 2013

Small non-coding RNAs (sRNAs) facilitate host-microbe interactions. They have a central function in the post-transcriptional regulation during pathogenic lifestyles. Hfq, an RNA-binding protein that many sRNAs act in conjunction with, is required for Y. pestis pathogenesis. However, information on how Yersinia pestis modulates the expression of sRNAs during infection is largely unknown. We used RNA-seq technology to identify the sRNA candidates expressed from Y. pestis grown in vitro and in the infected lungs of mice. A total of 104 sRNAs were found, including 26 previously annotated sRNAs, by searching against the Rfam database with 78 novel sRNA candidates. Approximately 89% (93/104) of these sRNAs from Y. pestis are shared with its ancestor Y. pseudotuberculosis. Ninety-seven percent of these sRNAs (101/104) are shared among more than 80 sequenced genomes of 135 Y. pestis strains. These 78 novel sRNAs include 62 intergenic and 16 antisense sRNAs. Fourteen sRNAs were selected for verification by independent Northern blot analysis. Results showed that nine selected sRNA transcripts were Hfq-dependent. Interestingly, three novel sRNAs were identified as new members of the transcription factor CRP regulon. Semi-quantitative analysis revealed that Y. pestis from the infected lungs induced the expressions of six sRNAs including RyhB1, RyhB2, CyaR/RyeE, 6S RNA, RybB and sR039 and repressed the expressions of four sRNAs, including CsrB, CsrC, 4.5S RNA and sR027. This study is the first attempt to subject RNA from Y. pestis-infected samples to direct high-throughput sequencing. Many novel sRNAs were identified and the expression patterns of relevant sRNAs in Y. pestis during in vitro growth and in vivo infection were revealed. The annotated sRNAs accounted for the most abundant sRNAs either expressed in bacteria grown in vitro or differentially expressed in the infected lungs. These findings suggested these sRNAs may have important functions in Y. pestis physiology or pathogenesis. Source

Sun S.,Beijing Institute of Microbiology and Epidemiology
PloS one | Year: 2011

Fulminant hepatic failure (FHF) is a clinically severe type of liver injury with an extremely high mortality rate. Although the pathological mechanisms of FHF are not well understood, evidence suggests that the complement system is involved in the pathogenesis of a variety of liver disorders. In the present study, to investigate the role of complement in FHF, we examined groups of mice following intraperitoneal injection of LPS/D-GalN: wild-type C57BL/6 mice, wild-type mice treated with a C3aR antagonist, C5aR monoclonal antibody (C5aRmAb) or CR2-Factor H (CR2-fH, an inhibitor of the alternative pathway), and C3 deficient mice (C3-/- mice). The animals were euthanized and samples analyzed at specific times after LPS/D-GalN injection. The results show that intraperitoneal administration of LPS/D-GalN activated the complement pathway, as evidenced by the hepatic deposition of C3 and C5b-9 and elevated serum levels of the complement activation product C3a, the level of which was associated with the severity of the liver damage. C3a receptor (C3aR) and C5a receptor (C5aR) expression was also upregulated. Compared with wild-type mice, C3-/- mice survived significantly longer and displayed reduced liver inflammation and attenuated pathological damage following LPS/D-GalN injection. Similar levels of protection were seen in mice treated with C3aR antagonist,C5aRmAb or CR2-fH. These data indicate an important role for the C3a and C5a generated by the alternative pathway in LPS/D-GalN-induced FHF. The data further suggest that complement inhibition may be an effective strategy for the adjunctive treatment of fulminant hepatic failure. Source

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