Production of Monoclonal Antibodies in Plants for Cancer Immunotherapy

Table 3

Comparison of recombinant protein expression in leaves (tobacco) and seeds (rice).

Characteristics	Leaves (tobacco)	Seeds (rice)
Technical feasibility	(i) Easy transformation ability; (ii) Protein production in leaf stem tissues (medium level of expression); (iii) Glycosylation occurs with nuclear transformation; glycosylation occurs with chloroplast transformation, reducing flexibility of protein production	(i) Relatively easy transformation ability; (ii) Stable protein storage in grain (high level of expression); (iii) Glycosylation makes high flexibility in protein production
Production feasibility	(i) Fair germplasm base available; (ii) Easy purification, more difficult with tissue based production; (iii) More byproduct with tissue based production	(i) Very good germplasm base available; (ii) Ease of purification good if targeted to endosperm; (iii) More limited byproduct with grain
Containment	(i) Seed production typically difficult; chloroplast transformation reduces dissemination by seed; (ii) Minimum 1/4 mile isolation distance; (iii) Seed dormancy in soil less than 2 years; (iv) Crop does not persist without intervention	(i) Primarily self-fertilized; (ii) Relatively lower separation requirement; (iii) Presence of weedy red rice (relative) must be determined, mitigated, and monitored; (iv) Seed dormancy in soil is less than 2 years; (v) Crop does not persist without intervention
Environmental impact	Driven by specific protein	Driven by specific protein
Food/feed impact	(i) Nonfood or nonfeed crop; nontarget species unlikely to feed; (ii) Food safety generally not established; (iii) Risk driven by specific protein	(i) Primarily a food crop; (ii) Rice itself is not orally toxic; (iii) Risk driven by specific protein