A Plant-Produced Candidate Subunit Vaccine Reduces Shedding of Enterohemorrhagic Escherichia coli in Ruminants.
Enterohemorrhagic Escherichia coli (EHEC) are commonly present in the gastrointestinal tract of cattle and cause serious infectious disease in humans. Immunizing cattle against EHEC is a promising strategy to decrease the risk of food contamination; however, veterinary vaccines against EHEC such as Econiche have not been widely adopted by the agricultural industry, and have been discontinued, prompting the need for more cost-effective EHEC vaccines. The objective of this project is to develop a platform to produce plant-made antigens for oral vaccination of ruminants against EHEC. Five recombinant proteins were designed as vaccine candidates and expressed transiently in Nicotiana benthamiana and transplastomically in Nicotiana tabacum. Three of these EHEC proteins, NleA, Stx2b, and a fusion of EspA accumulated when transiently expressed. Transient protein accumulation was the highest when EHEC proteins were fused to an elastin-like polypeptide (ELP) tag. In the transplastomic lines, EspA accumulated up to 479 mg kg-1 in lyophilized leaf material. Sheep that were administered leaf tissue containing recombinant EspA shed less E. coli O157:H7 when challenged, as compared to control animals. These results suggest that plant-made, transgenic EspA has the potential to reduce EHEC shedding in ruminants.
['Miletic|Sean|S|', 'Hünerberg|Martin|M|', 'Kaldis|Angelo|A|', 'MacDonald|Jacqueline|J|', 'Leuthreau|Antoine|A|', 'McAllister|Tim|T|', 'Menassa|Rima|R|']
D000284:Administration, Oral D000818:Animals D004195:Disease Models, Animal D054324:Enterohemorrhagic Escherichia coli D004927:Escherichia coli Infections D019453:Escherichia coli O157 D029968:Escherichia coli Proteins D022361:Escherichia coli Vaccines D005243:Feces D018506:Gene Expression Regulation, Plant D007114:Immunization D008297:Male D018515:Plant Leaves D030821:Plants, Genetically Modified D012333:RNA, Messenger D011994:Recombinant Proteins D012418:Ruminants D012756:Sheep D022641:Shiga Toxin 2 D014026:Tobacco D014611:Vaccination D022223:Vaccines, Subunit D037521:Virulence Factors
EHEC veterinary vaccines oral vaccine E. coli O157:H7 molecular farming