Tumor cell surface ligands recognized by lymphokine-activated killer (LAK) cell receptors (LAK cell ligands)

Tumor cell surface ligands recognized by lymphokine-activated killer (LAK) cell receptors are a heterogeneous group of proteins upregulated on malignant cells in response to cellular stress, DNA damage, and transformation (Grimm et al., 1982, J. Exp. Med.). LAK cells, which primarily consist of natural killer (NK) cells and certain T cells activated by high-dose Interleukin-2 (IL-2), identify these ligands through a suite of specialized activating receptors such as NKG2D, DNAM-1, and Natural Cytotoxicity Receptors (NCRs) like NKp30 (Waldhauer & Steinle, 2008, Oncogene). Key ligands include MHC class I polypeptide-related sequences A and B (MICA/B), UL16-binding proteins (ULBPs), and B7-H6, which are typically absent or lowly expressed in healthy tissues but highly prevalent in various carcinomas and hematological malignancies (Brandt et al., 2009, J. Exp. Med.). Upon binding to these ligands, LAK cells execute a potent cytotoxic program involving the release of perforin and granzymes, which induce rapid apoptosis in the target tumor cell. Historically, LAK cell therapy was a pioneering form of adoptive immunotherapy for advanced cancers, though its clinical utility was often limited by the systemic toxicity of the high-dose IL-2 required for cell generation. Modern therapeutic strategies focus on preventing the proteolytic shedding of these ligands—a common immune evasion tactic used by tumors—or utilizing them as targets for chimeric antigen receptor (CAR) based therapies and bispecific killer cell engagers (BiKEs). Understanding the complex interaction between these ligands and LAK cell receptors remains a critical area of research for developing next-generation innate immune-based oncology treatments.

Other names

LAK cell targetsNK cell activating ligandsStress-induced ligandsNKG2D ligandsNatural cytotoxicity receptor ligandsNCR ligandsMICA/BULBPsB7-H6

Recognition of stress-induced ligands by activated LAK cell receptors triggers the release of cytotoxic granules (perforin and granzymes) and pro-inflammatory cytokines, leading to tumor cell lysis.