Evaluation of Intracellular Signaling Downstream Chimeric Antigen Receptors
Fig 2
The majority of CAR T cells are CD8+ effector or effector memory cells.
Lineage (A; CD3+ CD8+), exhaustion phenotype (B; PD-1+ Tim-3+) and memory/effector status (C) were evaluated by flow cytometry at start and after co-culture with autologous B cells and IL-2 or IL-2 alone. Graphs are showing CAR+ T cells, gated as viable singlet cells expressing CD3 and CAR. For memory/effector status the cells were divided into the following subtypes: naïve: CD45RA+ CCR7+, effector: CD45RA+ CCR7-, central memory (CM): CD45RA- CCR7+ and effector memory (EM): CD45RA- CCR7-. There was no statistical difference in expression of lineage or exhaustion markers between the different time-points or between groups. T cells of effector memory phenotype increased (IL-2 vs B/IL-2 3G: p = 0.0836, 2G: p = 0.1232), while effector cells decreased (start vs B/IL-2 3G: p = 0.0625, 2G: p = 0.0625). There was also a tendency to increased number of central memory cells (start vs B/IL-2 3G: p = 0.0625, 2G: p = 0.0625). Error bars represent SEM. Statistical differences were calculated with unpaired t-test with Welch correction and Wilcoxon matched-pairs signed rank test.