Activated alloreactive T-lymphocyte

Activated alloreactive T-lymphocytes are a subset of donor-derived T-cells that recognize and attack host tissues following a haploidentical hematopoietic stem cell transplant (HSCT) (Ferrara et al., 2009, Lancet). These cells undergo rapid expansion and activation upon encountering mismatched human leukocyte antigens (HLA) in the recipient, serving as the primary mediators of Graft-versus-Host Disease (GvHD) (Luznik et al., 2008, Blood). Therapeutic strategies focus on the selective depletion or suppression of this specific population to prevent GvHD while ideally preserving regulatory T-cells and non-alloreactive memory T-cells that provide anti-pathogen and anti-tumor immunity (Perruccio et al., 2005, Blood). Common pharmacological approaches include the use of post-transplant cyclophosphamide, which selectively eliminates proliferating alloreactive clones, or monoclonal antibodies targeting activation markers like CD25 (Kanate et al., 2016, JAMA Oncology). Managing this target is critical for the success of haploidentical transplants, as it balances the prevention of life-threatening GvHD with the maintenance of the essential graft-versus-leukemia effect (Appelbaum, 2007, NEJM).

Other names

Alloreactive T-cellsHost-reactive T-lymphocytesActivated donor T-cellsAlloreactive donor T-lymphocytes

Selective depletion of rapidly proliferating alloreactive T-cell clones through induction of apoptosis or mitotic arrest, typically sparing non-alloreactive memory T-cells and regulatory T-cells to maintain graft-versus-leukemia effects and immune competence.