Figure 5. The anti-tumor response to combined IL-6 and PD-L1 blockade is CD8⁺ T cell dependent.

Panc02 murine pancreatic tumor cells were subcutaneously injected into C57BL/6 mice with treatment beginning when tumors reached 50–100mm³. Mice were also depleted of either CD4⁺ or CD8⁺ T cells by injecting depletion antibodies on days 5, 6, 8, 11, and 14. A) Representative flow cytometry and B) quantification of CD4 and CD8 staining of splenocytes to confirm depletion. Means ± SD; *p<0.001. C) On day 7, mice were treated with 200 μg (intraperitoneal injection 3 times/week) of isotype controls or anti-IL-6 and anti-PD-L1 antibodies combined (n=5 mice/group) until mice met pre-specified IACUC-approved early removal criteria. Means ± SD; *p<0.001 compared to isotype; ^†p<0.002 CD8 depletion vs CD4 depletion.