Alloreactive T-lymphocyte response

Alloreactive T-lymphocyte responses against allogeneic hematopoietic stem cells (HSCT) represent the fundamental immunological process underlying both the therapeutic efficacy and the primary complications of bone marrow transplantation. This process occurs when donor-derived T-cells recognize recipient-specific antigens—primarily human leukocyte antigens (HLA) or minor histocompatibility antigens—as foreign (StatPearls, NBK538235). Upon recognition, these T-cells undergo rapid activation, clonal expansion, and differentiation into effector cells that release pro-inflammatory cytokines like IFN-gamma and TNF-alpha (PubMed, 25466600). While this alloreactivity is essential for the Graft-versus-Leukemia (GvL) effect, which eliminates residual malignant cells, it also drives Graft-versus-Host Disease (GvHD), where donor cells attack the recipient's healthy tissues, such as the skin, liver, and gut (Blood, 124/3/331). Pharmacological management focuses on modulating these responses using calcineurin inhibitors, antimetabolites, and targeted agents like JAK inhibitors (e.g., ruxolitinib) or costimulation blockers (e.g., abatacept) (NIH, PMC6626074). The central challenge in HSCT is achieving a 'GvHD-free, relapse-free survival' by balancing the suppression of harmful alloreactivity while preserving beneficial anti-tumor immunity.

Other names

Alloreactive T-lymphocyte responses against allogeneic hematopoietic stem cellsGraft-versus-host reactionT-cell alloreactivityAlloimmune responseGvHD mechanism

Inhibition of T-cell activation, proliferation, and effector function through calcineurin inhibition, JAK/STAT signaling blockade, mTOR inhibition, and costimulation interference.