Purpose of review: To evaluate the potential for mesenchymal stromal cells (MSCs) to regulate T-cell responses responsible for graft destruction following allogeneic islet transplantation (AIT).
Recent findings: Despite a high level of primary graft function being observed in most individuals following AIT, the majority of recipients require exogenous insulin within 5 years, presumably due to graft attrition. Although this process is not fully understood, recent evidence suggests that a combination of chronic allograft rejection and/or the recrudescence of anti-islet autoimmunity govern islet loss. Emerging reports highlight that the pathology of AIT may involve the proliferation, effector function and homeostatic expansion of alloreactive and autoreactive T-cell pools. MSCs exhibit several desirable characteristics, which may advocate their use in AIT. This includes the capacity to suppress alloreactive and autoimmune T-cell responses, and promote a cytokine environment that is likely to be graft protective. However, further work is needed to clarify if MSCs can function in the setting of immune suppression and discern how they may effect T-cell effector functions and influence homeostatic expansion.
Summary: MSCs exhibit the potential to regulate the T-cell-driven processes that underlie disease pathology in AIT, but further study may be required to maximize their therapeutic efficacy.