T-cell receptor (for T cell component) and NK cell receptor (for NK cell component) (TCR, NK cell receptor)

T-cell receptors (TCRs) are transmembrane protein complexes expressed on T lymphocytes that recognize antigenic peptides presented by self or foreign MHC molecules, initiating T cell activation and adaptive immunity. NK cell receptors encompass several families of receptors on natural killer cells that modulate cytotoxic responses, often via direct recognition of altered or missing self-MHC, or by binding stress-induced ligands. Allogeneic MHC presentation occurs, for example, during transplantation, when TCRs and certain NK cell receptors directly or indirectly recognize non-self (allogeneic) MHC molecules, leading to immune activation, graft rejection, or, conversely, beneficial graft-versus-tumor effects[2][3][6][5]. Both TCRs and NK cell receptors are crucial immune checkpoints and therapeutic targets in transplantation, oncology, and infectious disease.

Other names

TCRNatural killer cell receptorNK cell receptorAlloreactive T-cell receptorKiller-cell immunoglobulin-like receptorKIR

Modulation of immune response via blockade or activation of TCR/NK signaling pathways\nImmune checkpoint inhibition (anti-PD-1, anti-CTLA-4 removes inhibitory signals from T cells)\nActivation/expansion of T/NK cells (adoptive cell therapies)