Abstract
Hepatitis E virus (HEV) is a causative agent of hepatitis E. Recently, a novel hepatitis E-like virus was isolated from Norway rats in Germany. However, the antigenicity, pathogenicity and epidemiology of this virus are unclear because of the lack of a cell-culture system in which to grow it. In this study, an N-terminally truncated ORF2 protein was expressed in insect Tn5 cells using a recombinant baculovirus expression system and a large amount of 53 kDa protein was expressed and efficiently released into the supernatant. Electron microscopic analyses of the purified 53 kDa protein revealed that the protein self-assembled into two types of empty HEV-like particles (rat HEVLPs). The smaller rat HEVLPs were estimated to be 24 nm in diameter, which is similar to the size of genotype G1, G3 and G4 HEVLPs. The larger rat HEVLPs were estimated to measure 35 nm in diameter, which is similar to the size of native rat HEV particles. An ELISA to detect antibodies was established using rat HEVLPs as the antigens, which demonstrated that rat HEVLPs were cross-reactive with G1, G3 and G4 HEVs. Detection of IgG and IgM antibodies was performed by examination of 139 serum samples from wild rats trapped in Vietnam, and it was found that 20.9 % (29/139) and 3.6 % (5/139) of the samples were positive for IgG and IgM, respectively. In addition, rat HEV RNA was detected in one rat serum sample that was positive for IgM. These results indicated that rat HEV is widespread and is transmitted among wild rats.
Highlights
Hepatitis E virus (HEV) is the causative agent of hepatitis E, a viral disease that manifests as acute hepatitis (Emerson & Purcell, 2003)
Rat HEV is a new genotype of HEV, and nucleotide sequence identities with HEV G1–4 were 55.1–55.9 %
Because no cell-culture system has yet been developed for rat HEV, it remains necessary to express the capsid protein and generate virus-like particles (VLPs) in order to analyse the antigenicity and immunogenicity of this pathogen; these recombinant molecules are extremely useful for seroepidemiological studies of rat HEV infection in wild rats
Summary
Hepatitis E virus (HEV) is the causative agent of hepatitis E, a viral disease that manifests as acute hepatitis (Emerson & Purcell, 2003). 034835 G 2011 SGM Printed in Great Britain public health problem in developing countries and is transmitted primarily by the faecal–oral route (Balayan et al, 1983). A number of sporadic cases have been described, and the disease is primarily transmitted in a zoonotic fashion (Meng, 2010). The HEV genome is approximately 7.2 kb, containing a 59 non-coding region (27–35 nt) followed by three overlapping ORFs and a 39 non-coding region of approximately 65–74 nt followed by a poly(A) tail. ORF3, which partially overlaps with ORF2, encodes a cytoskeletonassociated phosphoprotein with multiple functions (Korkaya et al, 2001; Meng et al, 1997; Zafrullah et al, 1997)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
