94-OR: Lipid Nanoparticle-Mediated Delivery of Enhanced Costimulation Blockade to Prevent Type 1 Diabetes

Abstract

Type 1 diabetes (T1D) remains an untreatable autoimmune disease caused by the destruction of pancreatic beta cells by autoreactive T cells. Because of its complex etiology, many immunotherapy strategies have been investigated, but with disappointing results. Costimulation blockade, blocking the CD28 pathway via administration of CTLA4-Ig, is a promising approach, but recent observations suggest its efficacy is antagonized by inflammatory factors. As antigen presenting cells malfunctions and aberrant accumulation of type 1 interferons are associated with T1D, we pose that inhibiting the signaling of inflammatory cytokines via Tofacitinib (Tofa), a JAK inhibitor, would enhance the efficacy of CTLA4-Ig to prevent T1D development. The objective of this study was to design the controlled and localized delivery of Tofa via implementation of biocompatible lipid nanoparticles, Nanostructured Lipid Carrier (NLC), and assess the immunomodulatory impact of this strategy. We identified a specific composition of NLC that had negligible toxicity, could be readily taken up by multiple immune cells, and had a favorable Tofa encapsulation efficiency. Live animal imaging using fluorescently-labeled NLC confirmed that these particles have the unique property of accumulating in lymphoid tissues. Moreover, when administrated via oral gavage, they bypassed first-pass metabolism and accumulated in spleen, pancreatic and mesenteric lymph nodes. Ex-vivo, Tofa- NLC rapidly delivered Tofa to mouse antigen presenting cells preventing their maturation and the release of inflammatory cytokines. Ongoing experiments show that short-term administration of Tofa-NLC via oral gavage at early (3-week-old) or late (10-week-old) stage in NOD promotes a significant reduction of T1D onset. Overall, Tofa-NLC represent a promising strategy to complement CTLA4-Ig (currently investigated) and we envision this combination strategy could enhance the efficacy of antigen specific immunotherapy. Disclosure Y. Zhang: None. J. Wang: None. X. Calderon-Colon: None. O. Tiburzi: None. M. Iglesias Lozano: None. J. Patrone: None. G. Raimondi: None.