Micro- and Nano-particulate Strategies for Antigen Specific Immune Tolerance to Treat Autoimmune Diseases

An improper immune response towards a self-antigen can result in an autoimmune disease. Commonly these diseases are treated with therapies that suppress overall immune responses, which can lead to increased risk of infection and cancer. A more specific method would be to induce immune tolerance in an antigen specific manner. This is much like traditional vaccines that have antigen specificity towards the pathogen they are forming protection. This antigen specific protection is called immune tolerance and has been accomplished by introducing soluble antigen to mucosal routes (e.g. oral, nasal or sublingual). Unfortunately, this approach has shown limited success clinically. Nano and microparticles (MPs) have recently been applied as delivery vehicles to help improve efficacy in immune tolerance. MPs can increase the solubility and circulation of cargo and passively target macrophages and dendritic cells. Fabrication of MPs with diseaseassociated antigens has limited disease progression in animal models of Multiple Sclerosis, Type 1 Diabetes, and Rheumatoid Arthritis, which has corresponded to an antigen specific decrease in inflammatory responses. The use of MPs to induce antigen specific tolerance can limit the current therapeutic shortfalls such as adverse drug side effects and blanket suppression of the immune system, which can lead to an overall significant increase in patient quality of life.