CV1 does not hinder intrinsic CAR effector function. (A) 16 hour tumor lysis by WT and OrexiCAR T cells against CD19+ Raji. Average of 3 donors ± SEM. (B) Cytokine secretion was measured using Luminex after a 24 hour coculture with antigen plus tumor cells. Lines connect matched donors. (C) CD4/8 makeup of transduced cells (CD19–CAR+) was measured via flow cytometry (average of 4 donors). (D) NSG mice that underwent engraftment with Raji tumor cells were treated with WT or OrexiCAR T cells. After 30 days of engraftment, tumors were harvested by intraperitoneal lavage, and infiltrating T cells were analyzed via flow cytometry. (E) Cells isolated from the intraperitoneal cavity were cultured ex vivo and supernatant was analyzed for CV1 secretion, shown as absorbance, via ELISA after 4 days. The same supernatant was used to assess CD47 blocking of Raji tumor cells, shown as the percentage of CD47 cells. R2 value was determined using a standard linear regression analysis. n.s., not significant; SEM, standard error of mean; TNF, tumor necrosis factor.
