No abstract

The efficacy of a plant-based vaccine produced in maize by expressing F and HN immunogenic proteins under a seed-specific promoter against NDV genotype VII was assessed using cell-mediated responses in chickens. Using real-time PCR, the mRNA expression of F and HN PCR confirmed maize plants was compared to non-transgenic control plants on a relative basis. F and HN genes mRNA expression was found to be 20 and 60 times higher in corn seeds than in leaves, respectively. In maize seeds, 35 ug/ml of F protein, or 0.6 percent of total protein, and 41 ug/ml of HN protein, or 0.85 percent of total protein, were found using ELISA. The boost in cell-mediated immune response was evaluated in chickens fed with transgenic corn seeds in comparison with control groups. The qPCR analysis showed an increase in the expression of Interleukin-1 (IL-1), Interleukin-2 (IL-2), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), interleukin-15 (IL-15), Interferon-α, Interferon-β, Interferon-γ, and CCL3 when evaluated at 0-day, 7th day, 14th day, 21st day, 28th day and 35th day in chickens receiving transgenic diet as compared to group 1 receiving non-transgenic diet. The increase in cytokines production was comparable with group 3 immunized with conventional market vaccine. Furthermore, anti-NDV antibodies were also found in the serum of chickens given maize containing immunogenic proteins, but not in the serum of chickens fed a normal diet, demonstrating the specificity of the antibodies created through feeding. The data suggest that oral edible vaccinations are more useful in the chicken industry than in injectables.