Smallpox subunit vaccine produced in planta confers protection in mice

doi:10.1073/pnas.0701451104

Smallpox subunit vaccine produced in planta confers protection in mice

*Biotechnology Foundation Laboratories, Thomas Jefferson University, Philadelphia, PA 19107-6799;
^†Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104; and
^‡Icon Genetics, Biozentrum Halle, Weinbergweg 22, D-06120 Halle (Saale), Germany

Contributed by Hilary Koprowski, March 2, 2007 (received for review January 18, 2007)

Abstract

We report here the in planta production of the recombinant vaccinia virus B5 antigenic domain (pB5), an attractive component of a subunit vaccine against smallpox. The antigenic domain was expressed by using efficient transient and constitutive plant expression systems and tested by various immunization routes in two animal models. Whereas oral administration in mice or the minipig with collard-derived insoluble pB5 did not generate an anti-B5 immune response, intranasal administration of soluble pB5 led to a rise of B5-specific immunoglobulins, and parenteral immunization led to a strong anti-B5 immune response in both mice and the minipig. Mice immunized i.m. with pB5 generated an antibody response that reduced virus spread in vitro and conferred protection from challenge with a lethal dose of vaccinia virus. These results indicate the feasibility of producing safe and inexpensive subunit vaccines by using plant production systems.

Footnotes

^§To whom correspondence should be addressed. E-mail: hilary.koprowski{at}jefferson.edu
Author contributions: M.G., S.S., R.B., S.N.I., and H.K. designed research; M.G., S.S., V.A., Y.S., Y.X., N.P., K.M., and S.N.I. performed research; M.G., Y.S., R.B., and Y.G. contributed new reagents/analytic tools; M.G., S.S., V.A., Y.S., Y.X., N.P., K.M., and S.N.I. analyzed data; and M.G., S.S., N.P., and S.N.I. wrote the paper.
The authors declare no conflict of interest.
Abbreviations:

VV,

vaccinia virus;

CT,

cholera toxin;

TSP,

total soluble protein.