Plant-made vaccines against avian reovirus

Viral arthritis, chronic respiratory disease, malabsorption syndrome, hepatitis and myocarditis cause considerable economic losses in the poultry industry and are directly or indirectly linked to avian reovirus (ARV). The outer capsid proteins of the ARV, σC and σB, encoded by the S1 and S3 genome segments, respectively, are the prime candidates for development of a subunit vaccine against ARV infection. To develop a plant-based vaccine for immunizing poultry against ARV infection, transgenic alfalfa, Arabidopsis and tobacco expressing recombinant σC protein have been generated. Transgenic Arabidopsis with the highest expression of σC were used to subcutaneously or orally vaccinate specific-pathogen free (SPF) chickens. The Arabidopsis-expressed recombinant rC protein could induce immune response in chickens and conferred significant protection against viral challenge. Future investigations to improve theσCand/or σB protein levels in edible plants will pave the way for commercially large-scale vaccination against ARVs in the poultry industry.