Interferon-Induced Transmembrane Protein 3 Inhibits Hantaan Virus Infection, and Its Single Nucleotide Polymorphism rs12252 Influences the Severity of Hemorrhagic Fever with Renal Syndrome.

Hantaan virus (HTNV) causes hemorrhagic fever with renal syndrome (HFRS). Previous studies have identified interferon-induced transmembrane proteins (IFITMs) as an interferon-stimulated gene family. However, the role of IFITMs in HTNV infection is unclear. In this study, we observed that IFITM3 single nucleotide polymorphisms (SNP) rs12252 C allele and CC genotype associated with the disease severity and HTNV load in the plasma of HFRS patients. In vitro experiments showed that the truncated protein produced by the rs12252 C allele exhibited an impaired anti-HTNV activity. We also proved that IFITM3 was able to inhibit HTNV infection in both HUVEC and A549 cells by overexpression and RNAi assays, likely via a mechanism of inhibiting virus entry demonstrated by binding and entry assay. Localization of IFITM3 in late endosomes was also observed. In addition, we demonstrated that the transcription of IFITM3 is negatively regulated by an lncRNA negative regulator of interferon response (NRIR). Taken together, we conclude that IFITM3, negatively regulated by NRIR, inhibits HTNV infection, and its SNP rs12252 correlates with the plasma HTNV load and the disease severity of patients with HFRS.

Construction of eukaryotic expression vector expressing hepatitis C virus NS5B and EGFP fusion protein and establishment of stable transfected HepG2 cell line / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct a eukaryotic expression vector for expressing hepatitis C virus (HCV) recombinant NS5B-EGFP fusion protein and obtain a stable transfected HepG2 cell line.</p><p><b>METHODS</b>The coding region of NS5B gene of HCV was amplified by PCR and was digested by Xho I/Kpn I. This fragment was inserted into pEGFPN3 with T4 ligase and transformed E. coli TG1. The positive recombinant plasmid was selected, then the recombinant plasmid was transfected into HepG2 cell by Lipofectin AMINE 2000. Cells containing stable transformants were selected by the ability of resistance to G418 and isolated with a limited dilution. The stable transfected cell line expressing high level NS5B-EGFP fusion protein was obtained.</p><p><b>RESULTS</b>The eukaryotic expression vector named pEGFPN3-ns5b was successfully constructed and the stable transfected HepG2 cell line expressing NS5B-EGFP fusion protein was obtained.</p><p><b>CONCLUSION</b>The stable transfected HepG2 cell line could express NS5B-EGFP fusion protein, could be used for anti-HCV infection with ns5b gene as the target.</p>

Identification of oligopeptides mimicking the virus attachment protein of hantaan virus / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To identify and characterize the epitope associated with the virus attachment protein (VAP) of hantaan virus.</p><p><b>METHODS</b>The monoclonal antibody 3G1 was used as the ligand to biospan from a phage-displayed 12-amino acid peptide library, then the positive phage clones were chosen and sequenced. The amino acid sequences of them were compared with that of hantaan virus G2 in homology. The characteristics of positive phage were studied by IFA and ELISA. A decapeptide combining to cell membrane was observed under laser scanning confocal microscope (LSCM).</p><p><b>RESULTS</b>The conservative motif PX(1-2) HX(0-2) H displaying on positive clones shared homologous amino acid sequence with G2 96YPWHTAKCHY105.</p><p><b>CONCLUSION</b>G2 96YPWHTAKCHY105 might play some roles in virus binding to host cell, and might be a possible key epitope of hantaan virus VAP.</p>