Immune system modulation via transient donor chimerism

Transient donor chimerism refers to the temporary coexistence of donor and recipient hematopoietic or immune cells after transplantation, established through protocols involving hematopoietic cell transplantation and immunosuppression[1][2][4][5]. This state aims to induce donor-specific immune tolerance, allowing the recipient to accept transplanted organs or tissues without permanent immunosuppression[4][5]. Mechanistically, it promotes tolerance through a combination of central (thymic deletion of alloreactive T cells) and peripheral (regulatory T cell-mediated) mechanisms[2][4][5]. Unlike stable chimerism, which retains long-term donor cell persistence, transient chimerism wanes over time but can suffice to induce long-lasting organ-specific transplant tolerance in some protocols[4]. This approach is not a molecular target per se, but a cellular or immunological strategy, with significant potential and notable risks (e.g., GvHD, infection) in clinical transplantation settings[1][4]. This entry is considered “incorrect” as a target since it is a process, not a distinct molecular entity, receptor, or enzyme.

Other names

transient mixed chimerismtransient hematopoietic chimerismdonor chimerismdonor-derived chimerism

Induction of immune tolerance by temporary coexistence of donor and host immune cells Central deletion of alloreactive T cells in the thymus (central tolerance) Peripheral regulation through induction of regulatory T cells (peripheral tolerance)