Figure 1.

Tumor-derived CCL20 activated and induced PD-L1 expression on neutrophils. (a) Viability of neutrophils treated with recombinant human CCL20 or supernatant from MDA231cell lines. (b) CCL20 expression as determined by ELISA in cell culture supernatant from breast cancer cell lines. (c) The expression of CCL20, CD66b and PD-L1 in breast cancer tissues (Immunohistochemistry, ×400). (d and e) PD-L1 expression on neutrophils cultured with rhCCL20 and MDA-MB-231 supernatant in the presence of CCL20 neutralizing antibody as determined by immunofluorescence and flow cytometry, respectively