Secretory IgA antibodies from plants

Area of Science:

• Biotechnology
• Immunology
• Plant molecular biology

Background:

• Secretory IgA (SIgA) is crucial for mucosal immunity in mammals and birds.
• Monoclonal IgG antibodies are widely used in immunotherapy, but SIgA's potential is emerging.
• Challenges in in vivo SIgA production have limited its therapeutic development.

Purpose of the Study:

• To explore transgenic plants as a system for producing therapeutic SIgA.
• To evaluate the safety and efficacy of a plant-made SIgA (CaroRx) in a human clinical trial.
• To establish a model for developing future plant-derived SIgA therapeutics.

Main Methods:

• Utilizing transgenic tobacco plants for high-level monoclonal SIgA production.
• Characterizing SIgA expression, localization (endoplasmic reticulum), and secretion.
• Developing purification strategies using protein G affinity chromatography.
• Conducting a human clinical trial for topical oral administration.

Main Results:

• Transgenic plants efficiently produced high levels of monoclonal SIgA.
• CaroRx accumulated in tobacco leaves and was effectively purified.
• Topical oral treatment with CaroRx in human subjects demonstrated safety and efficacy.
• The study provides a framework for plant-made therapeutic SIgA development.

Conclusions:

• Transgenic plants are a productive and economical system for SIgA production.
• Plant-made SIgA (CaroRx) is a viable therapeutic candidate for mucosal protection.
• This work paves the way for novel plant-derived immunotherapeutics.