PD-L1 expression in the tumor microenvironment after MVA-BN-HER2 therapy.

<p>(<b>A</b>) Mice bearing CT26-HER-2 tumors were treated with MVA-BN-HER2 and tumor volume was measured on day 15 compared to control mice (* p<0.05). (<b>B</b>) Tumors were collected on day 16 and stained for PD-L1 (red), CD3 (green), and nuclei (DAPI, blue). Representative images show the edge of the tumor (periphery, denoted by white dashed line) and center of the tumor. (<b>C</b>) The percent of infiltrating CD3⁺ T was measured by flow cytometry on day 16. (<b>D</b>) The area density of PD-L1 on all cells (IHC, **** p<0.0001). (E) Higher magnification images showing the co-localization of PD-L1 (red) and CD3 (green) after treatment. (<b>F</b>) Tumor sections were stained for PD-L1 (red), HER2 (green), and nuclei (DAPI, blue). n = 4 mice/group.