Regulation of response to antigen peptides is independent of peptide distribution in lymph node therapeutics

Autoimmune disease occurs when immune cells mistakenly identify specific molecules, termed antigens, on healthy cells. There are no cures for these diseases, and existing treatments - including monoclonal antibodies - do not specifically target dysfunctional cells. These challenges have motivated interest in therapies that could achieve antigen-specific immune tolerance. One concept involves co-delivery of self-antigens and regulatory cues to selectively redirect the response to self-antigen. Biomaterials have been investigated in this context owing to the control these technologies offer. We have shown degradable polymer depots encapsulating a self-antigen and delivered to lymph nodes enable reversal of autoimmune paralysis with a single treatment. However, human autoimmune disease is complex and often involves reactivity against sets of autoantigens, highlighting the need to deliver multiple antigens in new immunotherapies. Here we used these depots to encapsulate peptide antigens in distinct loading configuration - either with multiple peptides in a single particle or a single peptide in distinct particles. We show that both formulations are taken up by cells, and drive equivalent T cell responses both in vitro and in vivo. Notably, when loaded with an immunomodulatory cue, both formulations drive efficient polarization of antigen-specific T cells to regulatory T cells, supporting equivalency of both configurations for tolerizing therapy. Further, MPs can also be loaded with dynamic cargo loading levels without impacting size. The comparability of these two formulations holds significant promise to support simplified mix-and-match design and CMC development of peptide-loaded MPs as a flexible approach for autoimmune therapies.