PD1+ tumor associated macrophages predict poor prognosis of locally advanced esophageal squamous cell carcinoma

Aim: Tumor associated macrophages are the most abundant cancer immune cells. However, little was known about the identity of CD68(+)PD1(+) macrophages as well as the contributions in the prognosis of esophageal squamous cell carcinoma (ESCC). Methods & methods: Immunofluorescence, flowcytometry and RT-PCR were used to analysis PD1(+) macrophages in ESCC. Results: CD68(+)PD1(+) macrophages which can express higher M2 markers in cancer tissues, increased about 4.2-times compared with para-cancer tissues. Additionally, PD1(high) macrophages were significantly correlated with more malignant phenotypes and poor prognosis. PD1 treatment can enhance phagocytosis of cultured macrophages and redirect this macrophage to M1-like phenotype. Conclusion: Thus, our findings overall indicate that CD68(+)PD1(+) macrophages are tumor associated macrophagess in ESCC, which can forecast the prognosis of ESCC.