Enhanced Suppression of the Xenogeneic T-Cell Response In Vitro by Xenoantigen Stimulated and Expanded Regulatory T Cells

Strategies to prevent xenograft rejection while minimizing long-term immunosuppression need to be developed for successful xenotransplantaion. Polyclonally expanded human regulatory T cells (Treg) are known to suppress xenogeneic responses in vivo and in vitro. However, the risk of opportunistic infection and malignancy and the requirement for large numbers of Treg for effective suppression remain drawbacks to their clinical application. This study aimed to expand human Treg with xenoantigen stimulation and to assess their effectiveness at suppressing the xenoimmune response.