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

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). Immunofluorescence, flowcytometry and RT-PCR were used to analysis PD1 macrophages in ESCC. CD68 PD1 macrophages which can express higher M2 markers in cancer tissues, increased about 4.2-times compared with para-cancer tissues. Additionally, PD1 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. Thus, our findings overall indicate that CD68 PD1 macrophages are tumor associated macrophagess in ESCC, which can forecast the prognosis of ESCC.