title: Transient Bluetongue virus serotype 8 capsid protein expression inNicotiana benthamiana.
abstract: Bluetongue virus (BTV) causes severe disease in domestic and wild ruminants, and has recently caused several outbreaks in Europe. Current vaccines include live-attenuated and inactivated viruses; while these are effective, there is risk of reversion to virulence by mutation or reassortment with wild type viruses. Subunit or virus-like particle (VLP) vaccines are safer options: VLP vaccines produced in insect cells by expression of the four BTV capsid proteins are protective against challenge; however, this is a costly production method. We investigated production of BTV VLPs in plants viaAgrobacterium-mediated transient expression, an inexpensive production system very well suited to developing country use. Leaves infiltrated with recombinant pEAQ-HTvectors separately encoding the four BTV-8 capsid proteins produced more proteins than recombinant pTRA vectors. Plant expression using the pEAQ-HTvector resulted in both BTV-8 core-like particles (CLPs) and VLPs; differentially controlling the concentration of infiltrated bacteria significantly influenced yield of the VLPs.In situlocalisation of assembled particles was investigated by using transmission electron microscopy (TEM) and it was shown that a mixed population of core-like particles (CLPs, consisting of VP3 and VP7) and VLPs were present as paracrystalline arrays in the cytoplasm of plant cells co-expressing all four capsid proteins.
authors.affiliation: Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
authors.forename: Albertha R
authors.initials: AR
authors.lastname: van Zyl
authors.affiliation: Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
authors.forename: Ann E
authors.initials: AE
authors.lastname: Meyers
authors.affiliation: Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
authors.forename: Edward P
authors.initials: EP
authors.lastname: Rybicki
keywords: Agroinfiltration; Bluetongue virus; Nicotiana benthamiana; Paracrystalline arrays; Virus-like particle