Recent Patents on Immunoregulatory DNA Vaccines for Autoimmune Diseases and Allograft Rejection

The goal of immunoregulatory DNA vaccination is the antigen- and tissue-specific suppression of pathological inflammation that underlies immune-mediated inflammatory disorders like autoimmune diseases and allograft rejection. Recent patents and patent applications have applied immunoregulatory DNA vaccines in rodent model systems and human clinical trials using plasmid DNA coding for autoantigens such as insulin and glutamic acid decarboxylase for type 1 diabetes, myelin-associated proteins for multiple sclerosis, and heat sock protein 60 for rheumatoid arthritis. In these cases, the objective is to induce a homeostatic-like regulatory immune response to suppress pathological inflammation. In addition, patent applications have disclosed the use of DNA vaccines encoding the pro-inflammatory MIF cytokine and the CD25 IL-2 receptor subunit to interfere with the inflammatory process. Approaches have also been taken to improve DNA vaccination efficacy, including covalent modification of plasmid DNA, engineering secretion of vaccine-encoded antigen, and co-delivery of DNA coding for anti-inflammatory cytokines, a mutant co-stimulatory molecule, a growth factor, or a pro-apoptotic protein. Furthermore, a patent application has disclosed the use of a DNA vaccine previously shown to treat successfully an autoimmune disease to prolong allograft survival. Taken together, these patents and patent applications indicate a promising bench-to-bedside potential for immunoregulatory DNA vaccination applied to autoimmune diseases and allograft rejection.