Abstract

A.K. El Attar, A. M. Shamloul, A.A. Shalaby, B.Y. Riad, A. Saad, H.M. Mazyadand J.M. Keith

Hepatitis C virus (HCV) is the major etiologic agent of blood transfusion–associated and sporadic non-A non-B hepatitis affecting more than 180 million worldwide. Vaccine development for HCV has been difficult and there is no vaccine or effective therapy against this virus. In this paper, we describe the development of an experimental plantderived subunit vaccine against HCV. Our subunit vaccine originates from a consensus HCV-HVR1 epitope (R9) that antigenically mimics many natural HVR1 variants. This HVR1 sequence was cloned into the open reading frame of a plant virus, Alfalfa Mosaic Virus (ALMV) coat protein (CP) . The chimeric ALMV RNA4 containing sequence-encoding R9 epitope was introduced into full-length infectious ALMV-RNA3 that was utilized as an expression vector. The recombinant chimeric protein is expressed in transgenic tobacco plants (P12) expressing ALMV RNA1 and 2. Plant– derived HVR1/ALMV-CP reacted with HVR1 and/or ALMV-CP specific monoclonal antibodies and immune sera from individuals infected with HCV. Using plant-virus based transient expression to produce this unique chimeric antigen will facilitate the development and production of an experimental HCV vaccine. A plant derived recombinant HCV vaccine can potentially reduce expenses normally associated with production and delivery of conventional vaccine.