|Perez Filgueira, D.|
|Del Medico Zajac, M.|
Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2003
Publication Date: 10/20/2003
Citation: Perez Filgueira, D.M., Zamorano, P.I., Dominguez, M.G., Taboga, O., Del Medico Zajac, M.P., Puntel, M., Romera, S.A., Morris, T.J., Borca, M.V., Sadir, A.M. 2003. Bovine herpes virus g-d protein produced in plants using a recombinant tobacco mosaic virus (tmv) vector possesses authentic antigenicity. Vaccine. 21(27-30):4201-4209. Interpretive Summary: The tobacco mosaic virus as a vector to express recombinant foreign proteins during their infection cycle has been increasingly used. gD is the major immunogenic glycorotein of BHV-1, an important pathogen that produce abortion in cattle. Recombinant gD, produced in other expression systems has been shown to induce protection in experimentally vaccinated cattle. In this report a novel TMV-based vector was utilized for expression of the bovine herpesvirus 1 (BHV-1) protein gD (gD). Recombinant gDc protein of expected accumulated in the gD-TMV inoculated leaves to a concentration of about 20 µg/g of fresh leaf tissue. Oil-based vaccines were formulated with crude foliar extracts to immunize mice parentally, which, after a single injection, developed an anti-BHV-1 specific immune response to the native virus particles. Interestingly, cattle vaccinated with the same gDc containing vaccine developed specific humoral and cellular immune responses and, importantly, animals vaccinated with the plant-produced gDc were protected after challenge with the virulent BHV-1. Virus excretion was drastically reduced in these animals, reaching levels comparable to animals vaccinated with a commercial BHV-1 vaccine. This constituted the first report where a plant expressed recombinant immunogenic protein (gD) is successfully used to formulate an experimental vaccine that induce protection against the disease in the natural host (cattle).
Technical Abstract: A tobacco mosaic virus (TMV)-based vector was utilized for expression of a cytosolic form of the bovine herpesvirus type I(BHV-1) protein glycoprotein D (gDc). Nicotiana benthamiana plants were harvested 7 days after inoculation with RNA transcripts derived from the TMV-gDc recombinant virus. Recombinant gDc protein of expected electrophoretic mobility accumulated in inoculated leaves to a concentration of about 20 ug/g of fresh leaf tissue. Oil-based vaccines were formulated with crude foliar extracts to immunize mice parentally. After a single injection, animals developed a sustained and specific response to both the isolated gD and native virus particles. Cattle vaccinated with the same gDc containing extracts developed specific humoral and cellular immune responses directed against both the viral gD and BHV-1 particles. Most importantly, animals vaccinated with the plant-produced gDc showed good levels of protection after challenge with the virulent BHV-1. Virus excretion was drastically reduced in these animals, reaching levels comparable to animals vaccinated with a commercial BHV-1 vaccine. The positive immunological characterization obtained for the gDc, indicated that an important part of the natural conformation was retained in the plant recombinant protein.