Figure 2.

VSV-hgp100 Therapy Induces Acute CD8⁺ Effector Cell Expansion and Marked Expression of PD-1 and TIM-3

(A) Mice were challenged first with B16-OVA s.c. tumor then with i.v. tumor. Beginning on day 9, and continuing every other day during the week, the mice received a total of six doses of VSV-hgp100 or PBS. The mice were sacrificed at the indicated time points. (B) Gating strategy showing representative CD8⁺ effector (CD44^hiCD62L^lo) cells and their expression of PD-1 and TIM-3. (C and D) Blood flow cytometry. The frequencies of effector cells gated on CD8⁺ cells and frequencies of PD-1⁺ TIM-3⁺ cells gated on CD8⁺ effectors are shown. Each of the points represents 3–5 mice/group. (E and F) Splenic frequencies of CD8⁺ CD44⁺ effector cells and PD-1 and TIM-3 double positive effector cells. Each of the points represents 1–5 mice/group. (G and H) Frequencies of PD-1 or TIM-3 double negative, single positive, or double positive cells gated on CD8⁺ effectors in the blood. The above results are representative of three independent experiments with n = 1–5 mice per group. (I and J) Blood tetramer staining for the frequency and number of CD8⁺ effector cells reactive to the immunodominant VSV N peptide. (K and L) Splenic staining for the frequency and number of VSV N Tetramer⁺ CD8⁺ effector cells. The median with interquartile range is shown. ****p < 0.0001, ***p < 0.001, **p < 0.01, and *p < 0.05. The significance was determined at p < 0.05.