Figure 5.

Intratumoral mPH-762 generates systemic treated-tumor reactive CD8+ memory T cells in peripheral lymphoid organs. IT mPH-762 2 mg generates tumor specific systemic CD8⁺ T cells expanded ex vivo from peripheral lymphoid organs (pooled mesenteric lymph nodes and spleens) isolated on Day 14 of the in vivo study. Samples from individual mice were pooled by in vivo treatment for analysis. (A) Flow cytometry plots show memory reactivity of the ex vivo CD8⁺ CD3⁺ T cells isolated from each in vivo treatment group as marked by intracellular IFN-γ production in response to matched (Hepa1-6) or mismatched (CT26) tumor cell challenge, or to positive control stimulation (PMA/ionomycin) or unstimulated control conditions. (B) Fold-change %IFN-γ ⁺ CD8⁺/CD3⁺ events compared to those observed in the IT PBS treated group by challenge condition. (C) Flow cytometry plots show memory reactivity of the ex vivo CD8⁺ CD3⁺ T cells isolated from each in vivo treatment group as marked by intracellular TNF-α production of the ex vivo CD8⁺ CD3⁺ T cells in response to each challenge. (D) Fold-change of %TNF-α⁺ CD8⁺/CD3⁺ events compared to those observed in the IT PBS treated group by challenge condition.