Fig. 1

Immunological mechanism of STAMP application on the skin during the type 1 diabetes treatment. Schematic of STAMP delivering lyophilized Schistosoma japonicum eggs into the skin, and the reaction of dermal inflammation system and insulin secretion of pancreas islets. As the STAMP penetrated the stratum corneum by a thumb press, a shear force was applied to separate the tips off the base layer. The eggs remained in the epidermis after the biodegradation of CA-CMC and sustained the soluble egg antigen (SEA) release, interacting with local antigen-presenting cells (APC). Under the impact of antigen presented by APC, CD4⁺ T cells tended to differentiate into Th2 cells, which could produce protective cytokines (IL-4, IL-5, IL-10 and IL-13) to ameliorate the degree of pancreatic lesions and facilitate insulin secretion. Meanwhile, Th1 cell was down-regulated, leading to less secretion of the inflammatory cytokines (IL-2, IFN-γ, TNF-α and IL-12), thus reducing the damage of pancreatic β cells. Moreover, the regulatory Th cell (Treg cell) was up-regulated, generating more regulatory cytokines (IL-10 and TGF-β) to polarize the Th2 response and suppress the Th1 response