Huanle Luo

Publications (3)10.51 Total impact

• Article: Identification and Characterization of Complex Dual Nuclear Localization Signals in Human Bocavirus NP1.

  Qian Li, Zhenfeng Zhang, Zhenhua Zheng, Xianliang Ke, Huanle Luo, Qinxue Hu, Hanzhong Wang
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  ABSTRACT: Human bocavirus (HBoV), closely related to canine minute virus (MVC) and bovine parvovirus (BPV), is a new member of the Bocavirus genus within the Parvoviridae family. The non-structural protein NP1 of HBoV is a nuclear localized protein and plays important role in DNA replication as well as in the evasion of host innate immunity. In the current study, we provide the first evidence that NP1 possesses a non-classical nuclear localization signal (ncNLS) (amino acids 7-50). Embedded within this ncNLS is a classical bipartite nuclear localization signal (cNLS) (amino acids 14-28), capable of promoting a heterologous cytoplasmic protein β-galactosidase fusion protein (β-gal-EGFP) to the nucleus via the classical importin α/β1-mediated pathway. Amino acids 7-50 containing the cNLS and the ncNLS of NP1 or full-length NP1 interact with importin α1, importin β1 and importin β1Δ which lacks the importin α binding domain, indicating that the nuclear import of NP1 is through both conventional importin α/β1 heterodimer- and non-classical importin β1-mediated pathways. Given that the arrangement of a cNLS embedded within an ncNLS is unusual in viral proteins, our data together reveal a novel molecular mechanism underlying the nuclear import of HBoV NP1, providing basis for further understanding its biological function.
  Journal of General Virology 02/2013; · 3.36 Impact Factor
• Article: Human bocavirus NP1 inhibits IFN-β production by blocking association of IFN regulatory factor 3 with IFNB promoter.

  Zhenfeng Zhang, Zhenhua Zheng, Huanle Luo, Jin Meng, Hongxia Li, Qian Li, Xiaowei Zhang, Xianliang Ke, Bingke Bai, Panyong Mao, Qinxue Hu, Hanzhong Wang
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  ABSTRACT: Human bocavirus (HBoV) mainly infects young children. Although many infected children suffer from respiratory or gastroenteric tract diseases, an association between HBoV and these diseases is not definite. Because modulation of type I IFN is crucial for viruses to establish efficient replication, in this study, we tested whether HBoV modulates type I IFN production. We observed that a nearly full-length HBoV clone significantly reduced both Sendai virus (SeV)- and poly(deoxyadenylic-thymidylic) acid-induced IFN-β production. Further study showed that NP1 blocked IFN-β activation in response to SeV, poly(deoxyadenylic-thymidylic) acid, and IFN-β pathway inducers, including retinoic acid-inducible protein I, mitochondrial antiviral signaling protein, inhibitor of κB kinase ε, and TANK-binding kinase 1. In addition, NP1 interfered with IRF-3-responsive PRD(III-I) promoter activated by SeV and a constitutively active mutant of IRF-3 (IRF-3/5D). Although NP1 suppressed the IRF-3 pathway, it did not affect IRF-3 activation processes, including phosphorylation, dimerization, and nuclear translocation. Coimmunoprecipitation assays confirmed the interaction between NP1 and IRF-3. Additional deletion mutagenesis and coimmunoprecipitation assays revealed that NP1 bound to the DNA-binding domain of IRF-3, resulting in the interruption of an association between IRF-3 and IFNB promoter. Altogether, our results indicate that HBoV NP1 blocks IFN production through a unique mechanism. To our knowledge, this is the first study to investigate the modulation of innate immunity by HBoV. Our findings suggest a potential immune-evasion mechanism used by HBoV and provide a basis for better understanding HBoV pathogenesis.
  The Journal of Immunology 06/2012; 189(3):1144-53. · 5.79 Impact Factor
• Article: H5N1 influenza virus-like particles produced by transient expression in mammalian cells induce humoral and cellular immune responses in mice.

  Ling Tao, Jianjun Chen, Zhenhua Zheng, Jin Meng, Zhenfeng Zhang, Yao Chen, Huanle Luo, Hongxia Li, Ze Chen, Qinxue Hu, Hanzhong Wang
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  ABSTRACT: Vaccination is an effective way to protect from influenza virus infection. Among the new candidates of influenza vaccines, influenza virus-like particles (VLPs) seem to be promising. Here, we generated 2 types of H5N1 influenza VLPs by co-expressing influenza virus Env (envelope protein) and murine leukemia virus (MLV) Gag-Pol. VLPs generated by co-transfection of pHCMV-wtH5 or pHCMV-mtH5 with pSV-Mo-MLVgagpol and pHCMV-N1 were named as wtH5N1 VLPs or mtH5N1 VLPs. The plasmid of pHCMV-wtH5 encoded the wild-type hemagglutinin (HA) (wtH5) from A/swine/Anhui/ca/2004 (H5N1) with a multibasic cleavage site, while pHCMV-mtH5 encoded the modified mutant-type (mtH5) with a monobasic cleavage site. Influenza virus HA VLPs were characterized and equal amounts of them were used to immunize mice subcutaneously, intraperitoneally, or intramuscularly. The levels of HA-specific IgG1, IFN-γ, and neutralization antibodies were significantly induced in mice immunized with wtH5N1 VLPs or mtH5N1 VLPs via all 3 routes, while HA-specific IgG2a was barely detectable. IL-4 secretion was detected in mice subcutaneously immunized with wtH5N1 VLPs or mtH5N1 VLPs, or intramuscularly immunized with mtH5N1 VLPs. Our results indicated that both H5N1 influenza VLPs could induce specific humoral and cellular immune responses in immunized mice. In conclusion, our study provides helpful information for designing new candidate vaccines against H5N1 influenza viruses.
  Canadian Journal of Microbiology 03/2012; 58(4):391-401. · 1.36 Impact Factor