Oral immunization of mice with transgenic tomato fruit expressing respiratory syncytial virus-F protein induces a systemic immune response

Respiratory syncytial virus (RSV) is one of the most important pathogens of infancy and early childhood. Here a fruit-based edible subunit vaccine aga inst RSV was developed by expressing the RSV fusion (F) protein gene in tra nsgenic tomato plants. The F-gene was expressed in ripening tomato fruit un der the control of the fruit-specific E8 promoter. Oral immunization of mic e with ripe transgenic tomato fruits led to the induction of both serum and mucosal RSV-F specific antibodies. The ratio of immunoglobulin subclasses produced in response to immunization suggested that a type 1 T-helper cell immune response was preferentially induced. Serum antibodies showed an incr eased titer when the immunized mice were exposed to inactivated RSV antigen .