Killer-cell immunoglobulin-like receptor–Human leukocyte antigen interaction axis (KIR–HLA axis)

The Killer-cell immunoglobulin-like receptor–Human leukocyte antigen (KIR–HLA) interaction axis is a fundamental regulatory mechanism of the innate immune system, primarily controlling the activation and effector functions of natural killer (NK) cells (Vivier et al., 2012, Nature). Inhibitory KIRs on NK cells bind to specific HLA class I ligands on the surface of potential target cells, providing an inhibitory signal that prevents the destruction of healthy self tissue (Purdy & Campbell, 2009, Cancer Biology & Therapy). In the context of oncology, many tumors exploit this inhibitory pathway by maintaining HLA expression to evade immune detection and suppress NK cell-mediated surveillance. Therapeutic interventions targeting this axis, such as the monoclonal antibody lirilumab, seek to disrupt these inhibitory signals, thereby releasing the brakes on NK cells to enhance their anti-tumor cytotoxicity (Vey et al., 2012, Blood). Beyond cancer, this axis is a critical determinant in the success of hematopoietic stem cell transplantation and the pathogenesis of various autoimmune and infectious diseases (Ruggeri et al., 2002, Science).

Other names

KIR-MHC class I interactionNK cell inhibitory checkpointKIR-HLA signaling pathwayKIR-MHC class I axis

Checkpoint inhibition via blockade of inhibitory KIR receptors (e.g., KIR2DL1/2/3) to prevent the suppression of natural killer (NK) cell activity and enhance anti-tumor cytotoxicity.