Extended Data Fig. 5: Flow cytometry analyses of tumor-infiltrating B cells.

a, KPC tumors were resected on Day 14 of the treatment study, dissociated into single cells in suspension by Liberase digestion, and stained for CD19, CD69, and CD44. Viable lymphocytes were then analyzed by FACS. b, Expression of early activation marker CD69 and late activation marker CD44 in tumor-infiltrating B cells. c, B cells count in tumor and draining lymph node. Upper panels: The number of total CD19⁺ B cells or activated B cells per tumor was calculated from the total live cell count after tumor dissociation and the % fractions of these B cells as determined by flow cytometry (Fig. 4a). For each data point, three tumors were pooled, and the obtained cell number was divided by three to yield average B cell count/tumor. Total 6-9 tumors were examined. Lower panels: Similarly, the number of B cells in the draining lymph node was calculated from the total lymphocyte count in each lymph node and the % fraction of B cells in them. A representative result of two independent experiments is shown for each analysis. *p < 0.05; ***p < 0.01; **p < 0.001; ns, not significant. d, Total lymphocyte count in a draining lymph node. For each data point, six draining lymph nodes were pooled and averaged.