Figure 7.

Testing the therapeutic potency of MSC-IPr

(A) Kaplan-Meier survival curve. Tumor implantation is shown by the blue arrow, whereas vaccination is represented by black arrows. Tumor growth assessment of Ctl mice (black), DC (green), MSCγ (blue), or MSC-IPr (red). The anti-OVA western blot represents (1) OVA protein, (2) EL4, (3) cultured E.G7, and (4) E.G7 isolated from tumor masses.

(B and C) Flow cytometry assessment of immune-checkpoint expression by CD8 T cells isolated from tumor masses.

(D) A pie chart representing CD8 T cells expressing immune checkpoints.

(E) Kaplan-Meier survival curve of mice implanted with EL4 and vaccinated using lysate-pulsed MSC-IPr. MSC-IPr alone are in red, in combination with anti-41BB in dotted black line, anti-LAG3 in yellow, anti-CTLA4 in blue, or anti-PD-1 antibodies in orange. 4-1BB is represented by dotted blue line, anti-LAG3 is in gray, anti-CTL4 is in green, and anti-PD-1 is in purple.

(F) Kaplan-Meier survival curve of mice implanted as in (E) and receiving no treatment (black), anti-PD-1/4-1BB (purple), FTY720 (green), MSC-IPr + PD-1/4-1BB (orange), or MSC-IPr + PD-1/4-1BB and FTY720 (blue).

(G) Representative live in vivo imaging of mice implanted with luciferase-expressing Ctl MSCs versus MSC-IPr.

(H) Assessment of the signal decay for the experiment shown in (G).

(I and J) Experimental design and Kaplan-Meier survival curve of allogeneic vaccination using DCs (green), DCs + αPD-1 (dotted green), MSC-IPr (red), and MSC-IPr + αPD-1 (dotted red). Ctl mice are shown in black, whereas αPD-1 is in dotted black.

For (A) to (F) and (J), n = 10/group; for (G) and (H), n = 6/group, with ∗∗p < 0.01 and ∗∗∗p < 0.001. The log rank statistical test was used for the Kaplan-Meir survival curves. Error bars represent SD. See also Figures S8–S10.