Mucosal and systemic immunization elicited by Newcastle disease virus (NDV) transgenic plants as antigens

As a step towards developing a safe and effective edible vaccine against Newcastle disease virus (NDV), we have explored the use of plants genetically engineered to express viral proteins. We report the construction of transgenic potato plants expressing the genes coding for immunogenic proteins of NDV under the regulation of CaMV 35S promoter and its immunogenicity in mice. All mice receiving transgenic plant extracts in icomplete Freund adjuvant produced specific anti-NDV antibodies. Animals fed with transgenic leaves showed a specific response aganist NDV. Detection of IgA released from in vitro-cultured intestinal tissue fragments indicated the presence of IgA-secreting cells in the gut.