Figure 1:

Current approaches to Treg therapy. A schematic overview of the general Treg therapy approaches that have progressed into clinical trials, created with biorender.com. The left-hand panel illustrates adoptive cellular therapy (ACT) approaches starting with donation of autologous whole blood or a leukapheresis product from which the cell therapy is generated. Broadly, Treg ACTs may be classified as: polyclonal, indicating a broad TCR repertoire within the product; antigen specific, indicating a restricted TCR repertoire; or as Tregs transduced with a CAR comprising an ScFv towards a single antigen. The manufactured product is then infused back to the patient donor. The right-hand panel illustrates the approach taken to preferentially expand endogenous Treg in vivo through low dose IL-2 therapy. Here, exogenously administered IL-2 is expected to preferentially stimulate and expand Treg expressing the high affinity IL2Rα chain CD25 compared with the lower affinity dimeric IL2R expressed by effector cells.