Mucosal and systemic immunization elicited by Newcastle Disease Virus (NDV) transgenic plants as antigen

A. BERINSTEIN; C. VAZQUEZ-ROVERE; M. JUNCO; O. ZABAL; D. CONTEGRAND; F. ZANETTI; O. TABOGA; E. CARRILLO

Buenos Aires

Conferencia; OIE-IABs International Conference on the Control of Infectious Animal Diseases by Vaccination; 2004

Different studies have shown that it is possible to express viral epitopes and subunits of bacterial toxins in transgenic plants. It was also demonstrated that the recombinant proteins obtained using this technology induce specific immune responses and have several advantages over the commercial vaccines available nowadays. Newcastle disease virus (NDV) is a negative single stranded non segmented RNA virus. Two proteins of NDV envelope, the fusion (F) and haemaglutinin-neuraminidase (HN) proteins, have been related to the induction of protection against viral challenge. As a step towards developing a safe and effective edible vaccine against NDV, we have explored the use of plants genetically engineered to express viral proteins that were capable to induce a specific immune response. We report here the obtaintion of transgenic potato plants bearing the genes coding for immunogenic proteins of NDV under the regulation of CaMV 35S promoter and its immunogenicity in mice when administered parenterally or as edible vaccine. All mice receiving transgenic plant extracts in IFA produced specific anti-NDV antibodies tested by ELISA, demonstrating that NDV proteins were expressed in transgenic potato plants and that they were able to induce the production of anti-NDV antibodies. Animals fed with transgenic leaves showed specific response aganist NDV. Detection of IgA antibodies released from the in vitro-cultured intestinal tissue fragments from orally immunized mice indicated the presence of IgA-secreting cells in the intestinal tissue. This study demonstrates that oral vaccination with transgenic plants is a viable approach to the development of novel anti-NDV vaccines.