Tumor-associated stress ligand recognized by natural killer cell receptor

Tumor-associated stress ligands recognized by natural killer (NK) cell receptors comprise a group of cell surface molecules that are minimally expressed on healthy cells but become strongly upregulated on cells exposed to various forms of cellular stress, notably during malignant transformation or viral infection[1][2][3][6]. The principal family recognized by the NK activating receptor NKG2D includes the MHC class I chain-related proteins A and B (MICA and MICB), as well as the UL16-binding protein (ULBP) family (ULBP1–ULBP6) in humans. These ligands signal to NK cells (and certain T cells) that a target cell is stressed or transformed, leading to immune-mediated cell killing. Tumor-associated stress ligand expression is closely regulated, and its manipulation is a target for cancer immunotherapy. Overexpression is associated with favorable prognosis in some cancers, while tumor-driven downregulation or shedding confers immune escape and therapeutic resistance[1][3][6]. Note: The query refers to a *class* of ligands and not a single molecular entity; this complicates mapping to a single canonical name. For structure, each ligand (e.g., "MHC class I chain-related protein A (MICA)") should ideally be represented as its own target for precise annotation. The form "Tumor-associated stress ligands recognized by natural killer cell receptors" is **not** a standard canonical entity, but a descriptive category[1][3][6]. Summary of inaccuracy/ambiguity: - The entry refers to a group/family, not a single molecule, so is_incorrect: true. - Canonical entries should point to specific ligands such as "MICA", "MICB", or "ULBP2".[3][6]

Other names

NKG2D ligandStress-induced ligandMICAMICBULBP1ULBP2ULBP3UL16-binding proteinMHC class I chain-related A/B

Activation of natural killer (NK) cells and cytotoxic T cells via recognition and binding of upregulated ligands on stressed/tumor/infected cells, resulting in targeted cell lysis[1][3][6].