Stem Cell-Based Strategies for Immune Modulation to Achieve Transplantation Tolerance Without Rejection

Transplantation rejection continues to pose a major obstacle in clinical practice, requiring lifelong immunosuppression that carries substantial adverse effects. Therapies derived from stem cells, especially those employing mesenchymal stem cells (MSCs), have arisen as potential approaches to regulate immune reactions and promote acceptance of non-native tissues. We conducted a systematic review of existing literature to assess the capacity of stem cells to induce transplantation tolerance while avoiding rejection, with particular attention to their immunological features, therapeutic uses, and clinical results. The review highlights the dual role of MSCs in suppressing effector immune cells while promoting regulatory mechanisms, thereby creating an immunomodulatory microenvironment conducive to graft acceptance. Clinical research indicates the viability of MSC-based treatments in lowering rejection incidents, yet differences in methods and results highlight the necessity for uniform methodologies. Furthermore, we investigate the application of MSC-derived products, including extracellular vesicles, which preserve immunomodulatory properties and reduce potential hazards linked to whole-cell therapies. The results indicate stem cell-based approaches possess considerable promise, yet additional mechanistic research and extensive trials are needed to improve their effectiveness and safety. This review synthesizes current understanding and pinpoints essential deficiencies, establishing a basis for subsequent investigations focused on employing stem cells to attain lasting transplantation tolerance.