LNFPIII and GAS6 Signaling Nanoparticles for Tolerance Delivery in T1D

Objective: The overall objective of this proposal is to develop and validate a novel nanoparticle-based immunomodulatory platform for effective tolerance induction for T1D. The innovative aspect of this proposal lies explicitly in the engineering of two signaling molecules to the surface of nanoparticles to enhance their tolerogenic interaction with host cells, leading to the induction of suppressor cells capable of effectively controlling autoimmunity. Background/Rationale: We have previously established an effective tolerogenic vaccine for controlling autoimmunity. The tolerogenic vaccine is manufactured by crosslinking the autoantigen of interest to self spleen cells via a chemical crosslinker called ethylene carbodiimide and is then given intravenously. To circumvent the need for processing large numbers of patient cells for manufacturing the tolerogenic vaccine, we have recently tested bioengineered nanoparticles as carriers for antigen delivery. We observed that plain nanoparticles carrying antigens are suboptimal as tolerogenic vaccines compared with spleen cells carrying antigens. This observation prompted us to rationalize that there must exist additional tolerogenic signals on spleen cells that are not on nanoparticles. Through our preliminary studies, we identified two such missing signals from nanoparticles: CD209 and Mer. Therefore, we hypothesize that engineering the signaling capacity for CD209 and Mer to nanoparticles will significantly enhance the tolerogenicity of nanoparticle vaccines. We propose to test our hypothesis by two specific aims: (1) To develop synthetic nanoparticles decorated with two signaling molecules for CD209 and Mer called LNFPIII and GAS6 respectively, and to determine if the modified nanoparticles can effectively induce tolerogenic features when interacting with murine macrophages in cultures; (2) To test the efficacy of the decorated nanoparticles carrying a modified β cell autoantigen in preventing and reverting clinical diabetes in NOD mice. Anticipated Outcome: We anticipate that engineering signaling molecules for CD209 and Mer signaling to nanoparticles will significantly enhance their tolerogenic interaction with host cells, and when loaded with a relevant β cell autoantigen will result in effective control of autoimmunity in NOD mice. Relevance to Type 1 Diabetes: Critical knowledge gained by our proposed studies will provide valuable insights for the eventual design of a nanoparticle-based immune tolerance delivery platform for effective tolerance induction in T1D patients.