Precision Editing of Cyclophilin A Generates Cyclosporine and Voclosporin Resistant Cellular Therapies
Recipients of allogeneic transplants or patients with autoimmune disease require immune suppression, often with calcineurin inhibitors. There is an expanding repertoire of immune effector cell therapies, including CD19 CAR-T cells and viral-specific T cells, deployed in these patients; however, ongoing calcineurin inhibition may be detrimental to cell therapy function. We developed a CRISPR/Cas9-based approach to engineer dual cyclosporine/voclosporin resistant cell therapies by targeting PPIA (encoding cyclophilin A), a critical binding partner for both drugs. Because Cyclophilin A has homeostatic functions in T cells, a complete knock-out is detrimental to cell viability. We thus targeted its C-terminus, disrupting drug binding while leaving the majority of the protein intact. C-terminal editing was stable throughout expansion and preserved Cyclophilin A expression. Edited CD19 CAR-T cells retained effector function in the presence of cyclosporine and voclosporin, including proliferation, cytokine production, and target cell killing, resulting in improved survival in murine models of CD19+ leukemia. Edited CMV-specific T cells also demonstrated preserved antigen-specific proliferation and cytokine production in the presence of these drugs. C-terminal editing of Cyclophilin A offers a promising avenue for developing next-generation cell therapies for patients receiving calcineurin inhibitors.