title: Recombinant Hepatitis E virus like particles can function as RNA nanocarriers.
abstract: BACKGROUND
  Assembled virus-like particles (VLPs) without genetic material, with structure similar to infectious virions, have been successfully used as vaccines. We earlier described in vitro assembly, characterisation and tissue specific receptor dependent Clathrin mediated entry of empty HEV VLPs, produced from Escherichia coli expressed HEV capsid protein (pORF2). Similar VLP's have been described as a potential candidate vaccine (Hecolin) against HEV.
  
  
  RESULTS
  We have attempted to use such recombinant assembled Hepatitis E virus (HEV) VLPs as a carrier for heterologous RNA with protein coding sequence fused in-frame with HEV 5' region (containing cap and encapsidation signal) and investigated, if the relevant protein could be expressed and elicit an immune response in vivo. In vitro transcribed red fluorescent protein (RFP)/Hepatitis B virus surface antigen (HBsAg) RNA, fused to 5'-HEV sequence with cap and encapsidation signal (1-249 nt), was packaged into the recombinant HEV-VLPs and incubated with five different cell lines (Huh7, A549, Vero, HeLa and SiHa). The pORF2-VLPs could specifically transfer exogenous coding RNA into Huh7 and A549 cells. In vivo, Balb/c mice were immunized (intramuscular injections) with 100 µg pORF2-VLP encapsidated with 5'-methyl-G-HEV (1-249 nt)-HBsAg RNA, blood samples were collected and screened by ELISA for anti-pORF2 and anti-HBsAg antibodies. Humoral immune response could be elicited in Balb/c mice against both HEV capsid protein and cargo RNA encoded HBsAg protein.
  
  
  CONCLUSIONS
  These findings suggest that other than being a possible vaccine, HEV pORF2-VLPs can be used as a promising non-replicative tissue specific gene delivery system.
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India. subrat@gmail.com.
authors.forename: Subrat Kumar
authors.initials: SK
authors.lastname: Panda
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India. neekap2008@gmail.com.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Kapur
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India. daizypaliwal@gmail.com.
authors.forename: Daizy
authors.initials: D
authors.lastname: Paliwal
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India. hdurgapal@gmail.com.
authors.forename: Hemlata
authors.initials: H
authors.lastname: Durgapal
mesh_terms: D000818:Animals; D002460:Cell Line; D018014:Gene Transfer Techniques; D006514:Hepatitis B Surface Antigens / Q000235:genetics* / Q000276:immunology; D016752:Hepatitis E virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D056724:Immunity, Humoral; D007114:Immunization; D008807:Mice, Inbred BALB C; D012313:RNA / Q000008:administration & dosage* / Q000235:genetics* / Q000493:pharmacokinetics; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology; D014771:Virion / Q000235:genetics* / Q000276:immunology
chemical_list: D006514:Hepatitis B Surface Antigens; C400971:ORF2 protein, Hepatitis E virus; D014764:Viral Proteins; D012313:RNA