Production of proinflammatory cytokines by expressing Newcastle disease
vaccine candidates in corn
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.