Alloantigen-driven immune response

The alloantigen-driven immune response is a complex immunological process triggered when the immune system recognizes alloantigens—molecules, particularly MHC/HLA proteins, that differ genetically between individuals of the same species. This response underlies transplant rejection and graft-versus-host disease and involves both innate and adaptive immune mechanisms. The process is mediated largely by T lymphocytes that recognize alloantigens via three main pathways: direct, indirect, and semi-direct allorecognition. The interaction of these cells with alloantigen-presenting cells initiates a coordinated cascade of events, including T-cell and B-cell activation, cytokine secretion, and sometimes generation of donor-specific antibodies. Suppressing this response is the cornerstone of transplantation immunosuppression.

Other names

Alloreactive immune responseAlloresponseAlloimmune response

Suppression of T-cell activation; Inhibition of cytokine production; Blocking costimulatory signals (e.g., inhibition of CD28-CD80/CD86 interaction); Depletion of lymphocyte populations