Inducing Tolerance with Novel tolDC Systems
A failure of central immune tolerance driven by autoantigen specific T regulatory (Treg) cells is a major cause of many autoimmune diseases. Restoration of proper autoantigen Treg specific response holds promise as a highly effective, long-term therapy for a wide variety of autoimmune diseases. Generating autoantigen specific Tregs remains a challenge due to the non-specific nature of most tolerizing agents and the complexities of generating Tregs in vivo. We have identified a new push/pull method for inducing antigen-specific Treg tolerance via induction of tolerogenic dendritic cells (tolDCs).
We identified a combination of three tolerogenic drugs, dexamethasone, simvastatin and SC-514, which when used in combination with toll-like-receptor (TLR) agonists induces an active tolDC phenotype. When the tolerogenic combination was packaged into a liposome with a model antigen such as ovalbumin (OVA), these tolDCs induce differentiation of OVA specific Tregs both ex vivo and in vivo. We examined the tolerizing potential of the combination in an experimental autoimmune encephalomyelitis (EAE) disease model. Given the antigen specificity of this technique, this paper presents an attractive preclinical autoimmune therapy.
Combining TLR agonist and immunomodulatory drugs generates tolerogenic APCs in vitro.