Alloreactivity (null)

Alloreactivity Overview

Alloreactivity is the ability of immune cells, most notably T lymphocytes, to recognize and respond to antigens (usually MHC molecules) from a genetically different individual of the same species[1][3][5][7]. This immune response is a major barrier to organ and tissue transplantation, as the recipient's immune system may attack the transplanted tissue (graft rejection), or in hematopoietic stem cell transplantation, donor immune cells can attack the host (graft-versus-host disease)[7][9]. Alloreactivity involves direct and indirect recognition: T cells can directly recognize foreign donor MHC-peptide complexes, or indirectly recognize donor antigens presented by self-MHC[7][6]. The phenomenon is not itself a druggable molecular target or receptor, but rather arises from the functional interplay of T cell receptors, MHC molecules, and peptides from donor cells[3][6][8].

Mechanism of Action

Immunosuppression (e.g., drugs reduce T cell alloreactivity by suppressing immune cell activation)

Biological Functions

Safety Considerations