Innate TCR-chain engagement drives human T cells toward distinct memory-like effector phenotypes with immunotherapeutic potentials

Clonotypic alpha beta T cell responses to cargoes presented by major histocompatibility complex (MHC), MR1, or CD1 proteins underpin adaptive immunity. Those responses are mostly mediated by complementarity-determining region 3 motifs created by quasi-random T cell receptor (TCR) gene rearrangements, with diversity being highest for TCR gamma delta. Nonetheless, TCR gamma delta also displays nonclonotypic innate responsiveness following engagement of germline-encoded V gamma-specific residues by butyrophilin (BTN) or BTN-like (BTNL) proteins that uniquely mediate gamma delta T cell subset selection. We now report that nonclonotypic TCR engagement likewise induces distinct phenotypes in TCR alpha beta(+) cells. Specifically, antibodies to germline-encoded human TCRV beta motifs consistently activated na & iuml;ve or memory T cells toward core states distinct from those induced by anti-CD3 or superantigens and from others commonly reported. Those states combined selective proliferation and effector function with activation-induced inhibitory receptors and memory differentiation. Thus, nonclonotypic TCRV beta targeting broadens our perspectives on human T cell response modes and might offer ways to induce clinically beneficial phenotypes in defined T cell subsets.