title: Challenges in creating a vaccine to prevent hepatitis E.
abstract: Recombinant hepatitis E virus capsid protein (HEV CP) assembles orally immunogenic virus-like particles (VLP) when expressed in an insect cell system. We used plant expression cassettes, pHEV101 and pHEV110, for transformation of potato to express HEV CP, and 10 independent transgenic lines of HEV101 and 6 lines of HEV110 were obtained. ELISA for HEV CP was performed on tuber extracts. Accumulation of HEV CP in tubers varied from about 5 to 30 microg/g fresh tuber depending on the transgenic plant line. We further compared the expression levels with the yield of tubers for each line. Tuber yield varied less than expression levels, and ranged from about 600 to 1000 g per pot. Although Western blot showed that apparently intact HEV CP accumulated, we observed very limited assembly of virus-like particles in potato tubers. Oral immunization of mice with transgenic potatoes failed to elicit detectable anti-CP antibody response in serum, suggesting that VLP assembly is a key factor in orally delivered HEV CP vaccines.
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, NY, USA.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Maloney
authors.forename: Naokazu
authors.initials: N
authors.lastname: Takeda
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Suzaki
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ami
authors.forename: Tian Cheng
authors.initials: TC
authors.lastname: Li
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Miyamura
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Arntzen
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Mason
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D016751:Hepatitis E / Q000276:immunology* / Q000517:prevention & control*; D051379:Mice; D018515:Plant Leaves / Q000821:virology; D030821:Plants, Genetically Modified / Q000276:immunology*; D011198:Solanum tuberosum; D014614:Vaccines, Synthetic / Q000276:immunology; D014761:Viral Hepatitis Vaccines / Q000276:immunology*
chemical_list: D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines