In vivo induction of regulatory T cells promotes allergen tolerance and suppresses allergic contact dermatitis

A low inflammatory, Langerhans cell-targeted microprojection patch to deliver ovalbumin to the epidermis of mouse skin

“…The LCs of the skin are well known to elicit either an antigen-specific immune regulation (e.g. Treg) [68,69] or immune activation (e.g. Th1/Th2) [22,70], however, the inflammatory threshold for LC-induced immune activation is yet to be determined.…”

Engineering Immune Tolerance with Biomaterials

“…However, when these treatments are given as soluble systemic administrations they require frequent dosing due to short half‐life; such regimens result in exposure of non‐target tissues to the treatment. Since particulate materials drive more efficient uptake by APCs—and because biomaterials offer tunable release rates—these carriers have recently been harnessed to overcome the challenges above by providing controlled release of a number of tolerogenic immunomodulators, including immunosuppressants metabolic modulators, TLR agonists, regulatory cytokines, and ligands for receptors that promote tolerogenic function in DCs. However, the vast majority of these investigations have been in preclinical models.…”

“…While these designs do not function as tolerogenic vaccines, they can serve to modulate the phenotype of previously activated T cells, or T cells undergoing priming against self‐antigens being presented as a result of ongoing inflammation. This approach has been applied to locally induce T REG by providing sustained concentrations of regulatory immune signals which favor T REG differentiation over inflammatory T cell phenotypes . Another strategy involves administering MP depots to locally deliver chemoattractants which selectively recruit T REG to sites of inflammation .…”

Regulatory T Lymphocytes in Periodontitis: A Translational View

“…In a recent report, biodegradable poly(ethylene glycol)-poly(lactic- co -glycolic acid) (PEG-PLGA) microparticles were engineered to release TGF- β , RAPA, and IL-2 to locally induce Treg polarization in an in vivo model of allergic contact dermatitis [ 83 ]. The prophylactic treatment with these microparticles increased the Treg/Teff ratio in the skin draining lymph nodes, suppressing the T cell-mediated delayed-type hypersensitivity and rendering systemic and specific tolerance to contact allergens [ 84 ]. In another study, PLGA microspheres encapsulating recombinant mouse CCL22 were formulated to enhance local recruitment of CCR4 + Tregs in a murine model of dry eye disease [ 84 ].…”

“…The prophylactic treatment with these microparticles increased the Treg/Teff ratio in the skin draining lymph nodes, suppressing the T cell-mediated delayed-type hypersensitivity and rendering systemic and specific tolerance to contact allergens [ 84 ]. In another study, PLGA microspheres encapsulating recombinant mouse CCL22 were formulated to enhance local recruitment of CCR4 + Tregs in a murine model of dry eye disease [ 84 ]. The results showed that the microsphere treatment successfully prevents the inflammatory symptomatology by increasing the frequency of Tregs and decreasing the Teff in the lacrimal gland [ 85 ].…”