Fig. 3: The juxtaposition and interactions between LAMP3⁺DCs and CXCL13-expressing T cells contribute to better ICB response.

a Bubble plots represent the expression profiling of PDCD1 and CD274 in single cell clusters from scRNA-seq dataset. The plots are sized by the fraction of cells with positive gene expression, while the color represents the gene expression level. b The interactions among indicated cell clusters through PD1-PD-L1 axis from scRNA-seq dataset. c The box and whisker plot shows show the nearest distance from DC_LAMP3 to CD4_CXCL13 (N number of the counted cell-cell distances: distant stroma =918, boundary region=1867; tumor center=251) or (d) to CD8_CXCL13 (N number of the counted cell-cell distances: distant stroma =368, boundary region=567; tumor center=45) in distance stroma, tumor-stroma boundary and tumor center from treatment naïve dMMR patients. Data are represented as mean±IQR and analyzed by unpaired 2-tailed Student t test. ns, not significant; *, p < 0.05; **, p < 0.01. Pie charts represent the fractions of CD4_CXCL13 or CD8_CXCL13 in the indicated regions stratified by colors in accordance with (c) d. Data are analyzed by unpaired Student-t test. ns, not significant; ****, p < 0.0001. e Representative mIF images of panCK, COL1A1, PD-L1 and PD1 in treatment naïve dMMR patients (5 samples were analyzed). DAPI was used as a positive control for cell nuclei staining. Scale bars were set as 5 mm for global image (left) and 50μm for FOVs (middle and right). f The box and whisker plot shows the nearest distances from PD1⁺cells to PDL1⁺cells in distance stroma, tumor-stroma boundary and tumor center from 7 treatment naïve dMMR patients. Each dot represents a PD1-expressing cell. N number of the counted cell-cell distances: stroma = 750; boundary = 935; tumor = 892. Data are represented as mean ± IQR and analyzed by unpaired 2-tailed Student t test with Bonferroni correction. Ns, not significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001; ***, p < 0.0001. g The box and whisker plot shows the T cell exhaustion scores in the distant stroma, tumor-stroma boundary and tumor center from treatment naïve dMMR patients. Data are represented as mean±IQR and analyzed by unpaired 2-tailed Student t test. Ns not significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001; ***, p < 0.0001. N number of the spots: distant stroma =86, boundary region=12; tumor center=287. h Representative images of H&E staining, FOV, and spatial map of T cell exhaustion scores in the tumor-stroma boundary of the treatment naïve dMMR patient #56. Scale bars were set as 1.5 mm for global image (left) and 500 μm for FOVs⁷¹. i Heatmap of PDCD1 and CD274 expressions in the distant stroma, tumor-stroma boundary and tumor center of treatment naïve dMMR patients.