Figure 8.

The armored B2ARM CAR demonstrates high anti-tumor efficacy and increased memory T-cell persistence in vivo. (A) NSG mice were intradermally injected on the abdomen with 8 x10⁶ RPMI-8226 cells with overexpressed TGF-β (n = 5 per group). 2 x 10⁶ CAR+ T-cells were intravenously injected on day 17 after tumor implantation. On the day prior to T-cell infusion (day 16 after tumor implantation), 0.2 ug/ml of TGF-β were intratumorally injected. The exogenous TGF-β treatment was done every 3 days thereafter for a total of 5 injections. The differences in CAR expression levels were normalized by adjusting the total number of infused T-cells. Tumor progression (B–D) and changes in weight (E) were monitored after T-cell infusion. Dotted line denotes the complete resolution of tumors in the armored CAR T group on day 21, to facilitate comparison between treatments. Changes in tumor size were analyzed by one way ANOVA with Dunnett’s multiple comparisons test, ***p<0.001, ns, non-significant. On day 18 after T cell infusion, the absolute counts of (F) CD3+ cells, (G) CD3+CAR+ and (H) CD45RO+ (I) CD45RO+CD62L+, and (J) CD45RO+CD62L- cells in the peripheral blood of the mice were determined by counting beads and flow cytometric analysis. Statistical significance was determined by one way ANOVA with Tukey’s multiple comparisons test *p<0.05, **p<0.01.