Combined OX40L and mTOR blockade controls effector T cell activation while preserving T reconstitution after transplant.

A critical question facing the field of transplantation is how to control effector T cell (T) activation while preserving regulatory T cell (T) function. Standard calcineurin inhibitor-based strategies can partially control T, but breakthrough activation still occurs, and these agents are antagonistic to T function. Conversely, mechanistic target of rapamycin (mTOR) inhibition with sirolimus is more T-compatible but is inadequate to fully control T activation.