Fig. 3: Exosomes derived from tumors induce monocytes into PD1⁺ TAM in vitro.

a–c Exosomes were identified using an electron microscope, Nano-sight, and through western blotting. d, e On day 3, monocytes grown in presence or absence of supernatant or exosomes were enumerated with the help of flow cytometry to estimate the expression of PD1. Representative graphs are shown in d. e Data stand for the average of the three experiments performed independently. f On day 3, monocytes cultured in presence or absence of supernatant or exosomes were evaluated with the help of flow cytometry for evaluating the frequency of CD64, HLA-DR, and CD206 in monocytes. Data stand for average of the three experiments conducted independently b. g Estimation of the repressive property of monocytes cultured in presence or absence of supernatant or exosomes with the help of flow cytometry. Results stand for the mean of the three experiments carried out independently. h, i Estimation of IL-10 (h) and IL12p70 (i) levels in monocytes cultured in presence or absence of exosomes by ELISA. Data represent the average of three independent experiments. j On day 3, monocytes cultured in the medium with exosomes collected from ESCC cells in presence or absence of the exosome release inhibitor spiroepoxide were determined the PD1 level with the help of flow cytometry. *p < 0.05, **p < 0.01, ***p < 0.001 (Student’s t-test)