Natural Killer cell activating receptor ligands (NKARLs)

Natural Killer (NK) cell activating receptor ligands are a diverse group of cell surface proteins that are typically upregulated on cells undergoing malignant transformation, viral infection, or significant cellular stress [2, 3]. These ligands include the MHC class I polypeptide-related sequence A and B (MICA/B), the UL16-binding protein (ULBP) family, and nectin family members like CD155 and CD112 [2, 5]. They function as critical recognition signals for activating receptors on NK cells, such as NKG2D and DNAM-1, facilitating the immune system's ability to identify and eliminate abnormal cells [3]. In the context of SNK01, an autologous non-genetically modified NK cell therapy, these ligands serve as the primary targets for the expanded and highly activated NK cells [1, 4]. SNK01 is specifically engineered to maintain high expression of the receptors that bind these ligands, allowing for potent cytotoxicity even within immunosuppressive tumor microenvironments [1, 4]. The interaction between these ligands and SNK01 receptors leads to the targeted lysis of tumor cells through the release of cytotoxic granules and pro-inflammatory cytokines [4]. Because these ligands are often overexpressed in various solid tumors and hematologic malignancies while remaining largely absent from healthy tissues, they represent a vital axis for selective cancer immunotherapy [2, 5].

Other names

NKG2D ligandsDNAM-1 ligandsStress-induced ligandsNatural cytotoxicity receptor ligandsNCR ligandsTumor-associated NK ligands

SNK01 NK cells express high levels of activating receptors, including NKG2D, DNAM-1, NKp30, NKp44, and NKp46, which bind to their corresponding ligands on tumor cells [1, 4]. This binding triggers an intracellular signaling cascade within the NK cell, leading to the polarization of cytotoxic granules and the release of perforin and granzymes into the immunological synapse, ultimately inducing apoptosis in the target tumor cell [2, 5].