TILs localization affects NSCLC prognosis; the higher expression of IDO-1 and PD-L1 in poorly differentiated and more aggressive lung adenocarcinomas, as well as the correlation between high PD-L1 expression and squamous cell histotype, confirm the more efficient immunoescaping of these NSCLC subgroups.
In this study, surgically resected primary lung adenocarcinoma specimens from 427 patients were evaluated for IDO1 and PD-L1 expression by immunohistochemistry, and lung adenocarcinoma cell lines were evaluated for IDO1 and PD-L1 protein expression by enzyme-linked immunosorbent assay and flow cytometry and for messenger RNA levels by real-time reverse-transcriptase polymerase chain reaction analysis.