Characterization of the high anti-MM activities within the memory subsets of BCMA iPSC–T cells. (A, top) Representative flow cytometric analyses of the naïve:memory phenotype in BCMA iPSC–CD8⁺ T cells differentiated from BCMA-iPSC clones 1, 2, and 3. (A, bottom) Summary of total nonmemory (CD45RO⁻) and memory (CD45RO⁺) cell distribution on gated viable CD8⁺ T cells of the BCMA iPSC–T cells (N = 3; mean ± SD). (B) Summary of naïve (CD45RO⁻ CCR7⁺), CM (CD45RO⁺ CCR7⁺), EM (CD45RO⁺ CCR7⁻), and terminal effector (TE; CD45RO⁻ CCR7⁻) cell frequencies in BCMA iPSC–CD8⁺ T cells differentiated from each individual BCMA-iPSC clone. (C, top) Representative flow cytometric analyses demonstrating higher levels of CD107a degranulation and IFN-γ production within the CM and EM cell subsets of BCMA iPSC–CD8⁺ T cells than TE cells in response to U266 MM cells (effector-to-target cell ratio, 1:1). (C, bottom) Summary of 3 independent analyses (N = 3; mean ± SD). (D, top) Representative flow cytometric analyses demonstrating a significant induction of CD107a degranulation and Th1-type cytokine (IFN-γ/IL-2/TNF-α) production by CD45RO⁺ memory cells within BCMA iPSC–CD8⁺ T cells, not by CD45RO⁻ nonmemory cells, in response to U266 MM cells. Effector-to-target cell ratio, 1:1. (D, bottom) Summary of 3 independent analyses (N = 3; mean ± SD). (E, top) Representative flow cytometric analyses showing higher granzyme B production by the CM and EM cell subsets within BCMA iPSC–CD8⁺ T cells compared with TE cells in response to U266 MM cells. Effector-to-target cell ratio, 1:1. (E, bottom) Summary of 3 independent analyses (N = 3; mean ± SD). (F) Identification of unique clonotype TCRα and TCRβ sequences based on single cell sequencing (N = 88; single cells analyses) in the complementarity-determining region 3 of BCMA iPSC–T cells.