1. Constitutively active MyD88/CD40 costimulation enhances expansion and efficacy of chimeric antigen receptor T cells targeting hematological malignancies.
- Author
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Collinson-Pautz MR, Chang WC, Lu A, Khalil M, Crisostomo JW, Lin PY, Mahendravada A, Shinners NP, Brandt ME, Zhang M, Duong M, Bayle JH, Slawin KM, Spencer DM, and Foster AE
- Subjects
- Animals, Antigens, CD19 immunology, Cell Proliferation drug effects, HEK293 Cells, Humans, Immunotherapy, Adoptive methods, Lymphocyte Activation immunology, Mice, Mice, Inbred NOD, Signal Transduction immunology, THP-1 Cells, CD40 Antigens immunology, CD8-Positive T-Lymphocytes immunology, Hematologic Neoplasms immunology, Hematologic Neoplasms therapy, Myeloid Differentiation Factor 88 immunology, Receptors, Antigen, T-Cell immunology, Receptors, Chimeric Antigen immunology
- Abstract
Successful adoptive chimeric antigen receptor (CAR) T-cell therapies against hematological malignancies require CAR-T expansion and durable persistence following infusion. Balancing increased CAR-T potency with safety, including severe cytokine-release syndrome (sCRS) and neurotoxicity, warrants inclusion of safety mechanisms to control in vivo CAR-T activity. Here, we describe a novel CAR-T cell platform that utilizes expression of the toll-like receptor (TLR) adaptor molecule, MyD88, and tumor-necrosis factor family member, CD40 (MC), tethered to the CAR molecule through an intentionally inefficient 2A linker system, providing a constitutive signal that drives CAR-T survival, proliferation, and antitumor activity against CD19
+ and CD123+ hematological cancers. Robust activity of MC-enhanced CAR-T cells was associated with cachexia in animal models that corresponded with high levels of human cytokine production. However, toxicity could be successfully resolved by using the inducible caspase-9 (iC9) safety switch to reduce serum cytokines, by administration of a neutralizing antibody against TNF-α, or by selecting "low" cytokine-producing CD8+ T cells, without loss of antitumor activity. Interestingly, high basal activity was essential for in vivo CAR-T expansion. This study shows that co-opting novel signaling elements (i.e., MyD88 and CD40) and development of a unique CAR-T architecture can drive T-cell proliferation in vivo to enhance CAR-T therapies.- Published
- 2019
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