T cells can be re-directed to kill cancer cells using chimeric antigen receptors (CARs) or T cell receptors (TCRs). This approach, however, is constrained by the rarity of tumor-specific single antigens. Targeting antigens also found on bystander tissues can cause life-threatening adverse effects. A powerful way to enhance ON-target activity of therapeutic T cells is to engineer them to require combinatorial antigens. Here, we engineer a combinatorially activated T cell circuit in which a synthetic Notch receptor for one antigen induces the expression of a CAR for a second antigen. These dual-receptor AND-gate T cells are only armed and activated in the presence of dual antigen tumor cells. These T cells show precise therapeutic discrimination in vivo-sparing single antigen "bystander" tumors while efficiently clearing combinatorial antigen "disease" tumors. This type of precision dual-receptor circuit opens the door to immune recognition of a wider range of tumors. VIDEO ABSTRACT.

Redirecting T cells to attack cancer using engineered chimeric receptors provides powerful new therapeutic capabilities. However, the effectiveness of therapeutic T cells is constrained by the endogenous T cell response: certain facets of natural response programs can be toxic, whereas other responses, such as the ability to overcome tumor immunosuppression, are absent. Thus, the efficacy and safety of therapeutic cells could be improved if we could custom sculpt immune cell responses. Synthetic Notch (synNotch) receptors induce transcriptional activation in response to recognition of user-specified antigens. We show that synNotch receptors can be used to sculpt custom response programs in primary T cells: they can drive a la carte cytokine secretion profiles, biased T cell differentiation, and local delivery of non-native therapeutic payloads, such as antibodies, in response to antigen. SynNotch T cells can thus be used as a general platform to recognize and remodel local microenvironments associated with diverse diseases.