Tumor-associated stress antigens recognized by γδ T cell receptor

Tumor-associated stress antigens recognized by the γδ T cell receptor (TCR) represent a specialized class of cell-surface molecules that signal cellular distress, transformation, or infection to the innate-like immune system (Groh et al., 1998, Science). Unlike conventional αβ T cells that require peptide presentation on polymorphic MHC molecules, γδ T cells identify these stress-induced ligands—such as MHC class I polypeptide-related sequence A/B (MICA/B), UL16-binding proteins (ULBPs), and butyrophilin family members (BTN3A1/BTN2A1)—in a largely MHC-independent manner (Rigau et al., 2020, Science; Karunakaran et al., 2014, Immunity). This recognition mechanism allows γδ T cells to provide rapid, non-peptide-restricted immunosurveillance against "altered self" cells, particularly those that have downregulated MHC class I to evade traditional T cell detection. In oncology, these antigens are targeted to harness the potent cytotoxic and pro-inflammatory capabilities of γδ T cells. Therapeutic strategies include the use of aminobisphosphonates (e.g., zoledronic acid) to induce the accumulation of intracellular phosphoantigens that activate Vγ9Vδ2 T cells via butyrophilins, as well as novel monoclonal antibodies (e.g., ICT01) and bispecific γδ T cell engagers designed to bridge these stress antigens with the γδ TCR to trigger tumor lysis (Kunzmann et al., 2000, Blood; ImCheck Therapeutics, 2023).

Other names

Stress-induced γδ TCR ligandsTumor-associated stress antigens (TASA)MHC class I-related stress antigensButyrophilins and MHC-like moleculesNKG2D ligands (in the context of γδ T cell recognition)

Activation of γδ T cells through direct binding to stress-induced surface ligands or induction of endogenous phosphoantigen presentation to trigger anti-tumor cytotoxicity.