Table 2.

Treg cell-focused approaches to prevent transplant rejection and graft versus host disease (GvHD).

Type of therapy	Clinical/preclinical model	Outcomes
Corticosteroids	Immunosuppression in transplant patients affects Treg number and function, reviewed in (11)	Effective in preventing rejection, associated with short- and long-term adverse events (81)
Adoptive transfer(PolyTregs)	Phase I clinical trial demonstrating safety of polyTreg therapy in addition to IL-2 therapy (68)	Operational tolerance achieved in 7/10 patients (71) Risk of infection
Adoptive transfer (arTregs)	arTregs successfully home to the liver and prevent allograft rejection in preclinical skin graft model (82)	arTregs are significantly more effective than polyTregs (64, 82)
CAR-Tregs	Tailored Treg specificity using CARs specific for antigens relevant to liver transplantation. (83–86)	Encouraging results in human and preclinical skin allograft models (87, 88)
Enclysis Inhibitor	Enclysis inhibitors should be tested alongside current immunosuppression regimens in liver transplantation	Enclysis inhibitors could potentiate immunosuppression

PolyTreg, Polyclonally-expanded regulatory T cells; arTreg, Alloantigen-reactive regulatory T cells; CAR, Chimeric Antigen Receptor.