Specific cytotoxicity of BAR CD8s in vitro and in vivo. (A-B) Quantification of FVIII-specific spots formed by 3G6 and 413 hybridomas after coculture with BAR effector CD8 T cells (P = .0157). (C) Dose-dependent killing of target cells (BO2C11) by C2-BAR–expressing human CD8 T cells. (D) Loss of FVIII-specific IgG antibody secretion by BO2C11 cells at increasing effector:target (E:T) ratio of C2-BAR human CD8 T cells compared with controls (P < .05). (E) Schematic diagram of adoptive cell transfer into NSG mice and sample collection. (F) Kaplan-Meier survival analysis of NSG mice injected with BO2C11 hybridoma cells (n = 5). Log-rank (Mantel-Cox) test P = .0104. CPM, counts per minute; hCD8⁺, human CD8⁺; SD, standard deviation; SEM, standard error of the mean.