Killer cell lectin-like receptor subfamily K member 1–Retinoic acid early transcript 1 interaction (NKG2D–RAE1 interaction)

The NKG2D–RAE1 interaction (and its human equivalent, the NKG2D–RAET1/ULBP interaction) is a critical immune checkpoint involving the activating receptor NKG2D (KLRK1) and its stress-induced ligands. NKG2D is expressed on natural killer (NK) cells and various T cell subsets, while RAE1/RAET1 ligands are typically absent from healthy cells but upregulated during viral infection, DNA damage, or oncogenic transformation (PMID: 11777960). Engagement of NKG2D by these ligands triggers potent cytotoxic responses and cytokine production, serving as a danger signal to the immune system (PMID: 21737067). In oncology, this interaction is targeted by CAR-T cells (e.g., CYAD-01) and bispecific antibodies to direct immune cells against tumors (PMID: 30104715). Conversely, chronic activation of this pathway is implicated in autoimmune diseases like Crohn's disease and rheumatoid arthritis, where blocking antibodies are being investigated to reduce tissue inflammation (PMID: 25637456). A significant challenge in targeting this interaction is the shedding of soluble ligands by tumor cells, which can act as decoys and downregulate NKG2D expression, leading to immune evasion (PMID: 12114504).

Other names

NKG2D-ULBP interactionKLRK1-RAET1 interactionNKG2D-RAET1 interactionNKG2D-RAE1 complexKiller cell lectin-like receptor subfamily K member 1-Retinoic acid early transcript 1 interaction

Modulation of the NKG2D signaling pathway to either enhance anti-tumor immunity via receptor engagement (agonism/CAR-T) or inhibit pathological inflammation via receptor blockade (antagonism).