Neutralizing antibodies against rotavirus produced in identity¿preserved purple tomatoes

Abstract

Edible fruits are inexpensive biofactories of recombinant molecules for oral intake, which can be then delivered as crude extracts or partially purified formulations. Our group aims at the production of human antibodies for passive protection against mucosal pathogens in identitypreserved fruits. Tomato plants were transformed with a recombinant human immunoglobulin A (IgA_2A1) selected against the VP8* peptide of rotavirus SA11 strain. The expression levels of IgA_2A1 reached up to 5% of the total soluble protein in the transgenic fruit. Tomato crude extracts showed specific anti-VP8* binding activity up to 1/192 (FreshWeight:volume) dilutions, confirming the efficient assembly of IgA molecules with specific antigen-binding activity. Moreover, transgenic tomato extracts showed neutralizing activity against rotavirus SA11 strain in an in vitro neutralization assay. In order to make IgA_2A1 tomatoes easily distinguishable from the wild type, IgA_2A1 lines were crossed with metabolically¿engineered purple tomatoes expressing Anthirrhinum majus Rosea1 and Delila transcription factors. As a result, identity-preserved tomato fruits were obtained whose purple¿coloured juice contained high levels of health-promoting anthocyanins in combination with neutralizing anti¿rotavirus human IgA.