Fig. 3

PD-1⁺ T cells from myeloma mice expand ex vivo and secrete IFN-γ in response to myeloma following expansion. a Splenic PD-1⁺ and PD-1⁻ CD8⁺ T cells were sorted by flow cytometry, activated with anti-CD3 and anti-CD28, and expanded in culture for 7 days with 20 U/ml IL-2, 5 ng/ml IL-7 and 5 ng/ml IL-15. At the end of expansion, cells were counted and fold-expansion calculated. b The percentages of expanded cells expressing CD44 alone or CD44 and low levels of CD62L (CD62L⁻). The graph is representative of 4 independent experiments, 10–12 were mice pooled in each experiment. c The percentages of expanded PD-1⁺ or PD-1⁻ CD4⁺ T cells expressing Foxp3. The graph is representative of 4 independent experiments, 5 mice were pooled in each experiment. d Frequencies of IFN-γ-producing PD-1⁺ or PD-1⁻ CD8⁺ T cells in response to wild-type 5 T33 myeloma (5T33-WT), 5T33-WT myeloma plus 10 μg/ml anti-PD-L1 (5T33-WT + anti-PD-L1), or 5T33 myeloma cells expressing CD80 (5T33-CD80). The graph is representative of 3 independent experiments. ***p ≤ 0.001