Plant-made vaccines and reagents for the One Health initiative

Rybicki, Edward Peter

Our group accordingly used Agrobacterium-mediated transient expression in N benthamiana plants of a codon-optimised CCHFV N genewhich encodes the genome-associated nucleoprotein (NP) -to make a N-terminal 6xHis-tagged NP, that yielded »2mg protein / kg fresh plant material, was soluble, and was easily purified by a combination of ammonium sulfate precipitation and immobilised metal ion chromatography. The protein was used in an anti-IgG ELISA with a standard panel of 13 serum samples collected 5-15 y post infection from patients confirmed to have anti-CCHFV IgG using commercial immunofluorescent antibody tests. Serum samples from 13 volunteers with no CCHFV infection history were used as a negative control panel. The plant-produced NP detected anti-CCHFV IgG in all positive serum samples, while all negative serum samples gave results below the cut-off value. The results suggest that recombinant NP expressed in plants has significant potential for use in both diagnosis and surveillance, while probably being a better, more easily produced and purified reagent than what is available presently.