Nanoparticle-mediated delivery of cytokines for maintenance of the regulatory T cell phenotype

Compositions for delivery of growth factors needed for stable Tregs and methods of use thereof are provided. In preferred embodiments, the compositions can induce, increase, or enhance a functionally robust induced CD4 Treg population (e.g., Foxp3+ Treg) in vivo or ex vivo. The compositions generally include delivery vehicles including TGF-β and IL-2. Delivery vehicles include, for example, polymeric particles, silica particles, liposomes, or multilamellar vesicles. The TGF-β and IL-2 are typically co-loaded into, attached to the surface of, and/or enclosed within the delivery vehicle into the same particle for simultaneous co-delivery to cells such as T cells. Preferably the delivery vehicles are targeted to CD4. The compositions and cells treated therewith can be used in various methods of treating, for example, inflammation, inflammatory and autoimmune diseases and disorders, and inducing or maintaining tolerance including graft and transplant tolerance.