Abstract: The invention describes particles having a polypeptide shell. The polypeptide shell comprises at least one immunomodulatory polypeptide. Particles may be ultrasound-responsive particles, providing the ability to administer particles trandermally, or deliver particles to selected sites by use of ultrasound. Administration of the particles generates immunologic response to the polypeptide in the shell of the particle. The particles are therefore useful in methods of immunotherapy.