Figure 2.

CD4 CAR and CD4-IL15/IL15sushi CAR T cells reduce tumor burden in MOLM13 mouse model. (A) NSG mice were sub-lethally irradiated and intravenously injected with 1.0x10⁶ luciferase-expressing MOLM13 cells, an acute myeloid leukemia cell line that is 100% CD4+ to induce measurable tumor formation. Three days following tumor cell injection, 6 mice were intravenously injected with a course of 8x10⁶ vector control, CD4 CAR, or CD4-IL15/IL15sushi CAR T cells. On days 3, 6, 9, and 11, mice were injected subcutaneously with RediJect D-luciferin and subjected to IVIS imaging to measure tumor burden. (B) Average light intensity (photons/sec) measured for CD4 CAR and CD4-IL15/IL15sushi was compared to that of control to determine the percentage of tumor burden in treated versus control mice. By Day 6, CD4 CAR-treated mice had 52% lower tumor burden relative to control while CD4-IL15/IL15sushi-treated mice had 74% lower. Unpaired t-test analysis revealed a significant difference between control and two treatment groups by Day 9 (P = 0.0045). By Day 11, tumor burden was nearly 100% decreased in both CD4 CAR and CD4-IL15/IL15sushi CAR groups compared to control. (C) Mouse survival was compared across the groups. Log-rank analysis revealed a significant difference in survival of the two treatment groups compared to the control (P = 0.0003). Additionally, the CD4-IL15/IL15sushi CAR treatment group had a significantly improved survival compared to the CD4 CAR treatment group (P = 0.0087). ** means a p-value =< 0.01, also called "very significant".