Smart probes for optical imaging of T cells and screening of anti-cancer immunotherapies

T cells are an essential part of the immune system with crucial roles in adaptive response and the maintenance of tissue homeostasis. Depending on their microenvironment, T cells can be differentiated into multiple states with distinct functions. This myriad of cellular activities have prompted the development of numerous smart probes, ranging from small molecule fluorophores to nanoconstructs with variable molecular architectures and fluorescence emission mechanisms. In this Tutorial Review, we summarize recent efforts in the design, synthesis and application of smart probes for imaging T cells in tumors and inflammation sites by targeting metabolic and enzymatic biomarkers as well as specific surface receptors. Finally, we briefly review current strategies for how smart probes are employed to monitor the response of T cells to anti-cancer immunotherapies. We hope that this Review may help chemists, biologists and immunologists to design the next generation of molecular imaging probes for T cells and anti-cancer immunotherapies.

Automated summary

T cells play crucial roles in adaptive response and tissue homeostasis in the immune system. Smart probes, including small molecule fluorophores and nanoconstructs, have been developed to image T cells in tumors and inflammation sites by targeting metabolic and enzymatic biomarkers as well as specific surface receptors. This review summarizes recent advancements in the design, synthesis, and application of smart probes for imaging T cells, and discusses their use in monitoring T cell response to anti-cancer immunotherapies.