Extended Data Figure 7. Lung cancer and breast cancer cells release extracellular vesicles carrying PD-L1.

a, Immunoblots for PD-L1 in the whole cell lysate (“W”), purified exosomes (“E”), or microvesicles (“M”) from different lung cancer cell lines. The same amounts of proteins were loaded for each fraction. b, Immunoblots for PD-L1 in the whole cell lysate, purified exosomes, or microvesicles from the breast cancer cell line MDA-MB-231. The same amounts of proteins were loaded for each fraction. c, Immunoblots for PD-L1 in the whole cell lysate (“WCL”) or in the purified exosomes (“EXO”) from control (“C”) or IFN-γ-treated (“IFN”) lung cancer cells. The same amounts of exosome proteins from IFN-γ-treated and control cells were loaded (left panel). Quantification of the exosomal PD-L1 level determined by western blot analysis (right panel). d, Immunoblots for PD-L1 in the whole cell lysate or in the purified exosomes from control or IFN-γ-treated the breast cancer MDA-MB-231 cells. The same amounts of exosome proteins from IFN-γ-treated and control cells were loaded (left panel). Quantification of the exosomal PD-L1 level determined by western blot analysis (right panel). e, Representative contour plots of human peripheral CD8 T cells examined for the expression of Ki-67 and GzmB after treatment with H1264 cell-derived exosomes with or without blocking by IgG isotype or PD-L1 antibodies (left). The percentage of Ki-67⁺ or GzmB⁺ CD8 T cells is shown at the right panel. The experiments were repeated twice independently with similar results (a, b). Data represent mean ± s.d. of three (c-e) independent biological replicates. Statistical analyses are performed using two-sided unpaired t-test (c–e). For source data (a–d), see Supplementary Fig. 1.