Recombinant Hepatitis E virus like particles can function as RNA nanocarriers

Abstract

BackgroundAssembled 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.FindingsWe 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.ConclusionsThese 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.

Preparation of quadri-subtype influenza virus-like particles using bovine immunodeficiency virus gag protein

“…Recombinant VLPs have been used in immunological, structural and virus research including studying virus-host cell interactions (Charpilienne et al, 2002), as surrogates in environmental persistence and inactivation studies (Caballero et al, 2004) and as vehicles to deliver epitopes and genes (Panda et al, 2015; Pushko et al, 2013). Furthermore, VLPs have been often evaluated as safe and effective vaccines for many viruses including influenza (Kushnir et al, 2012; Pushko et al, 2013).…”

Liver-specific Gene Delivery Using Engineered Virus-Like Particles of Hepatitis E Virus

“…Gene delivery to liver-derived cells has already been explored using HBV- and HEV-like particles 33,34 . In those experiments, foreign molecules were displayed on the particle surface by recombinant expression vectors where the viral capsid protein and foreign genes were encoded.…”

Virus-Like Particles as an Instrument of Vaccine Production

“…It has been demonstrated that long DNA and RNA molecules may be incorporated into VLPs. For example, mRNA for the reporter protein, red fluorescent protein, was packaged into particles representing the hepatitis E capsids [50]. The plasmid containing the green fluorescent protein (GFP) gene was encapsidated into the VLPs assembled in vitro from the main capsid protein of the hamster polyoma virus [51].…”