Abstract
Objective This study was performed to investigate the expression status of CD155 and the association with exhausted CD4 + helper and CD8 + cytotoxic tumor-infiltrating lymphocytes (TILs) and programmed cell death-ligand 1 (PD-L1) in breast cancer microenvironment. Methods 126 breast cancer patients with invasive ductal breast cancer were recruited into this study consecutively. Immunohistochemistry was used to detect the expression CD155, PD-L1 and programmed cell death protein 1 (PD-1) on tumor-infiltrating immune cells and tumor cells in the microenvironment. Results The proportion of patients with CD155 expression was higher in triple negative breast cancer (72.7%) than Luminal A patients (22.2%, p<0.05). Patients with positive CD155 expression had higher percentage of CD4 + /PD-1 + helper TILs (30%) than patients with negative CD155 expression (21%, p<0.05). Patients with positive CD155 expression also had higher cell counts of exhausted CD4+ TILs (47 vs. 20/HPF) and unexhausted CD8+ TILs (30 vs. 17/HPF) than patients with negative expression (p<0.05). CD155 expression was correlated with an increased PD-L1 expression in immune cells, 0.8% and 0.02% immune cells expressing PD-L1 in patients with positive and negative CD155 expression, respectively (p<0.05). Conclusions CD155 was related with an inhibitory immune microenvironment of breast cancer. CD155 was associated with high proportion of exhausted CD4 + and unexhausted CD8 + TILs and high PD-L1 expression in immune cells.
Programmed cell death ligand-1 expression in tumor and immune cells is associated with better patient outcome and decreased tumor-infiltrating lymphocytes in uveal melanoma
