The risk of reactivity against healthy tissues: Novel CARs demand testing for overlooked binding properties.

A rapidly growing number of chimeric antigen receptors (CARs) is being translated into cell therapy for malignant and autoimmune diseases. While cancer cell-selective CAR targeting is undergoing continuous refinement, specific testing for overlooked recognition of healthy tissues is commonly not performed, which potentially results in underestimating of the risk of severe tissue damage upon CAR T cell application. Using the FcμR/IgM receptor/FAIM3/TOSO-specific CAR, designed to target chronic lymphocytic leukemia cells, we exemplarily outline a screen to uncover reactivities to healthy tissues and discuss the value of such pre-clinical testing to improve safety in CAR T cell application.

Weal and woe of interleukin-18 in the T cell therapy of cancer.

Chimeric antigen receptor (CAR) T cell therapy of solid cancer remains below expectations; adding cytokine help through IL-18 has shown remarkable efficacy in first clinical trials. As IL-18 is also a powerful driver of hyperinflammatory conditions, we discuss to what extent unleashing IL-18 is a double-edged sword in CAR T cell therapies.

Integrating binding affinity and tonic signaling enables a rational CAR design for augmented T cell function.

Background: The success of chimeric antigen receptor (CAR) T cell therapy for hematological malignancies has not yet translated into long-term elimination of solid tumors indicating the need for adequately tuning CAR T cell functionality.

Methods: We leveraged a translational pipeline including biophysical characterization and structural prediction of the CAR binding moiety, evaluation of cellular avidity, synapse formation, T cell motility, and functional capacities under repetitive target challenge and in sustained tumor control.

Results: As an example of clinical relevance, we derived a panel of anti-Her2 CARs covering a 4-log affinity range, all expected to target the same Her2 epitope.