Fig. 4. H3K27M neoepitope colocalizes with HLA class II-DR on tumor cells and myeloid cells.
a–c, PLA of primary tumor tissue of patient ID 1 (top) and ID 8 (bottom) with H3K27M and HLA-DR antibodies (red) in combination with 4′,6-diamidino-2-phenylindol (DAPI) nuclear staining (blue) alone (a), co-staining with GFAP (green) (b) and co-staining with IBA1 (green) (c). All PLAs were repeated independently twice with similar results. Scale bar in white, 30 μm; in gray, 10 μm. d, Pearson correlation of PLA spots per visual field with immunohistochemistry score of HLA-DR expression across seven patients with available FFPE tissue. A two-sided t-test was used. e, Result of automated segmentation following rolling ball background subtraction, filtering with Gaussian blur and maxima detection. Scale bar in white, 30 μm.