Alloreactive activated donor T lymphocyte (Alloreactive T cell)

Alloreactive activated donor T lymphocytes are a specialized subset of T cells from a donor that recognize and respond to the recipient's histocompatibility antigens as foreign. In the context of allogeneic hematopoietic stem cell transplantation, these cells undergo rapid activation and expansion upon encountering host antigens, leading to the systemic inflammatory condition known as Graft-versus-Host Disease (GvHD) (1.1.1, 1.4.3). While they are the primary drivers of tissue damage in the host's skin, liver, and gut, they also play a crucial role in the Graft-versus-Leukemia (GvL) effect by eliminating residual malignant cells (1.4.1, 1.4.4). Therapeutic targeting of these cells is a cornerstone of transplant medicine, utilizing strategies such as selective depletion with post-transplant cyclophosphamide or inhibition of their activation via calcineurin and Janus kinase inhibitors (1.4.1, 1.4.5). Modern clinical approaches strive to achieve a balance by specifically suppressing these alloreactive clones while preserving the broader T-cell repertoire necessary for defending against infections and maintaining anti-tumor immunity (1.2.3, 1.5.1).

Other names

Donor-reactive T lymphocyteHost-reactive T lymphocyteAllospecific T cellGraft-versus-host-reactive T cellAlloreactive donor T cell

Selective depletion of proliferating alloreactive cells, inhibition of T-cell receptor signaling, blockade of cytokine-mediated activation, and induction of apoptosis in host-reactive clones.