|Perez Filgueira, D.m.|
|Dus Santos, M.j.|
Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2004
Publication Date: 8/27/2004
Citation: Perez Filgueira, D., Mozgovoj, M., Wigdorovitz, A., Dus Santos, M., Parreno, V., Trono, K., Fernandez, F., Carrillo, C., Badiuk, L., Morris, T., Borca, M.V. 2004. Passive protection to bovine rotavirus (brv) infection induced by a brv vp8* produced in plants using a tmv-based vector.. Archives of Virology. 149:2337-2348. Interpretive Summary: The report describes the use of TMV as an expression vector for the expression of foreign recombinant antigens in plants. The results showed the feasibility of expressing VP8, a structural protein of the bovine rotavirus, and its use as experimental vaccine in mice. It is shown that suckling mice born of vaccinated dams presented a significant degree of protection against the challenge with virulent rotavirus. This is the first report showing the use of a plant derived rotavirus experimental vaccine.
Technical Abstract: Previously, we have used the tobacco mosaic virus (TMV) vector TMV-30B (Shivprasad et al., 1999) to express foreign viral immunorelevant antigens to be used as experimental immunogens. Here we present the development of a variant of the original TMV-30B vector which resulted from the addition of a 7 histidine sequence at the C-terminal end of the recombinant protein (TMV-30B-HISc). We used the TMV-30B-HISc to express the VP8* fragment from VP4 protein from bovine rotavirus (BRV) strain C-486 in N. benthamiana plants. Leaves were inoculated with the TMV-VP8-His vector and 7 days post-inoculation a recombinant protein of the expected size was purified by immobilized metal affinity chromatography (IMAC) at a concentration of 35 µg/ml of IMAC elution buffer. The plant-produced VP8* was initially detected with an anti-His tag mAb and its antigenicity was confirmed with a set of monoclonal and polyclonal specific sera. Adult female mice were inoculated by the intraperinoteal route with 3 doses of a vaccine containing 5 µg of either the recombinant VP8* or an unrelated protein obtained by the same protocol. Only mice vaccinated with the recombinant VP8* developed a specific and sustained response to the native VP8* from the homologous BRV. A second set of females were immunized with the same protocol and became pregnant between the second and third immunization. Suckling mice from immunized dams were challenged with the homologous virus at the fifth day of age. Eighty five percent of new born mice from mothers vaccinated plant-VP8* and only 35% of the pups from mothers immunized with the control protein were protected, a result statistically significant by the Exact Fisher Test (p<0.0004%). These results effectively indicated that the plant-produced VP8* was able to induce passive protection in the new born through the immunization of their dams suggesting its utility as an alternative source of production of recombinant protein for the development of anti-rotavirus vaccines.