Figure 3.

MM impairs proliferation of murine antigen-specific T cells in an ARG-dependent manner. C57BL/6 mice were i.v. inoculated with 1 × 10⁶ of Vĸ*MYC cells. In the 6th week of MM development, the mice were transferred with 1.5–2 × 10⁶ of CTV-stained CD8⁺ OT-I T cells, followed by the i.v. immunization with 10 µg of OVA protein on the next day. Proliferation of OT-I T cells in the spleens was evaluated in flow cytometry 3 days post immunization. ARG inhibitor INCB01158 was administered twice daily beginning from week 3 post MM induction. (A) Proliferation histograms. (B) Percentage of proliferating OT-I T cells in control (healthy C57BL/6 mice transferred with OT-I T cells and immunized with OVA protein) and MM-bearing mice treated were indicated with ARG inhibitor INCB01158. Graph presents means ± SD, n = 3. P-value was calculated using one-way ANOVA with Tukey’s post-hoc test.