Review Charts Shift Toward Treg-Based Active Tolerance in Solid Organ Transplantation
A 2026 review outlines the shift in solid organ transplantation from broad immunosuppression to Treg-based active tolerance. It covers polyclonal Tregs, CAR-Tregs and CRISPR-edited off-the-shelf products.
A review published April 30, 2026 in Immunity & Inflammation summarizes the trajectory of regulatory T cell therapies in solid organ transplantation from polyclonal expansion to gene-edited products. The article says achieving donor-specific immune tolerance while minimizing global immunosuppression has become the central goal of transplant immunology, and describes CAR-Tregs and hypoimmunogenic off-the-shelf Tregs as key steps in that shift.
Organ transplantation remains the cornerstone treatment for end-stage organ failure. While conventional broad-spectrum immunosuppression effectively controls acute rejection, it fails to address chronic rejection and carries long-term side effects including infection, malignancy, and metabolic disorders.
The review first summarizes the universal mechanisms by which Tregs function in solid organ transplantation. Through the secretion of inhibitory cytokines such as IL-10 and TGF-β, induction of effector T cell apoptosis, and modulation of dendritic cell function, Tregs establish durable immune tolerance both locally and systemically. The article says this multi-dimensional regulatory toolbox provides the fundamental biological basis for addressing rejection across different organs including the liver, kidney, and heart.
The review then traces the technological evolution of Treg therapy from bench to bedside. The initial phase involved polyclonal Tregs, with early research focused on expanding autologous Tregs ex vivo; while safety was established, this approach faced limitations including insufficient specificity and challenges in expansion efficiency.
The next phase brought CAR-Tregs. The introduction of CAR technology equipped Tregs with a "navigation system," enabling them to precisely recognize graft antigens and exert potent local immunosuppressive effects.
The most recent breakthrough involves off-the-shelf universal products. Gene-editing technologies such as CRISPR-Cas9 are being used to create hypoimmunogenic Tregs, and by knocking out human leukocyte antigen molecules, these engineered Tregs can evade the recipient's immune system, enabling standardized, scalable off-the-shelf availability.
The review says this stepwise technological evolution is driving transplant medicine away from a highly personalized and complex surgical procedure toward standardized, accessible cell drug therapy. It adds that integrating universal technology platforms such as universal CAR-Tregs with a deep understanding of organ-specific immune microenvironments is central to efforts to provide durable, stable immune tolerance across solid organ transplantation.