Bananas Used for Oral Vaccine to Treat PRRS
TAIWAN - Banana leaves can open new avenues for the production of vaccines against PRRSv according to a study in the Plant Biotechnology Journal.The research team of Hui-Ting Chan, Min-Yuan Chia, Victor Fei Pang, Chian-Ren Jeng, Pung-Ling Huang and Yi-Yin Do from the University of Taiwan examined the Oral immunogenicity of porcine reproductive and respiratory syndrome virus antigen expressed in transgenic banana.
The researchers said that porcine reproductive and respiratory syndrome virus (PRRSV) is a persistent threat of economically significant influence to the swine industry worldwide.
They proposed that recombinant DNA technology coupled with tissue culture technology is a viable alternative for the inexpensive production of heterologous proteins in planta. Embryogenic cells of banana cv. ‘Pei chiao’ (AAA) have been transformed with the ORF5 gene of PRRSV envelope glycoprotein (GP5) using Agrobacterium-mediated transformation and have been confirmed.
Recombinant GP5 protein levels in the transgenic banana leaves were detected and ranged from 0.021 per cent –0.037 per cent of total soluble protein.
Pigs were immunized with recombinant GP5 protein by orally feeding transgenic banana leaves for three consecutive doses at a two week interval and challenged with PRRSV at 7 weeks postinitial immunization.
A vaccination-dependent gradational increase in the elicitation of serum and saliva anti-PRRSV IgG and IgA was observed.
Furthermore, significantly lower viraemia and tissue viral load were recorded when compared with the pigs fed with untransformed banana leaves.
The results suggest that transgenic banana leaves expressing recombinant GP5 protein can be an effective strategy for oral delivery of recombinant subunit vaccines in pigs and can open new avenues for the production of vaccines against PRRSV.