Rapid production of specific vaccines for lymphoma by expression of the tumor-derived single-chain Fv epitopes in tobacco plants

Rapid production of protein-based tumor-specific vaccines for the treatment of malignancies is possible with the plant-based transient expression syst em described here, We created a modified tobamoviral vector that encodes th e idiotype-specific single-chain Fv fragment (scFv) of the immunoglobulin f rom the 38C13 mouse B cell lymphoma. Infected Nicotiana benthamiana plants contain high levels of secreted scFv protein in the extracellular compartme nt. This material reacts with an anti-idiotype antibody by Western blotting , ELISA, and affinity chromatography, suggesting that the plant-produced 38 C13 scFv protein is properly folded in solution. Mice vaccinated with the a ffinity-purified 38C13 scFv generate >10 mu g/ml anti-idiotype immunoglobul ins. These mice were protected from challenge by a lethal dose of the synge neic 38C13 tumor, similar to mice immunized with the native 38C13 IgM-keyho le limpet hemocyanin conjugate vaccine, This rapid production system for ge nerating tumor-specific protein vaccines may provide a viable strategy for the treatment of non-Hodgkin's lymphoma.