The Conflicting Role of Myeloid Cells in CAR T-Cell Therapy

Chimeric antigen receptor T (CAR T)-cell therapy is revolutionizing cancer treatment in hematologic malignancies, but challenges related to the tumor microenvironment have hindered CAR T success, especially in solid tumors. Myeloid cells in particular have been implicated in CAR T efficacy. In this review, we discuss the roles of myeloid cells in CAR T-associated toxicities, including cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, along with strategies to treat these toxicities by modulating myeloid cells. The review also explores myeloid cell-mediated suppression or enhancement of CAR T function. Finally, strategies used to target myeloid cells in combination with CAR T-cell therapy will be investigated.