MDSC subtypes and CD39 expression on CD8+ T cells predict the efficacy of anti PD-1 immunotherapy in patients with advanced NSCLC.

The major suppressive immune cells in tumor sites are myeloid derived suppressor cells (MDSCs), tumor associated macrophages (TAMs), and regulatory T (Treg) cells, and the major roles of these suppressive immune cells include hindering T cell activities and supporting tumor progression and survival. In this study, we analyzed the pattern of circulating MDSC subtypes in patients with non-small cell lung cancer (NSCLC) whether those suppressive immune cells hinder T cell activities leading to poor clinical outcomes. First, we verified polymorphonuclear -MDSCs (PMN-MDSCs), Monocytic-MDSCs (M-MDSCs), and Treg cells increased according to the stages of NSCLC, and MDSCs effectively suppressed T cell activities and induced T cell exhaustion. The analysis of NSCLC patients treated with anti PD-1 immunotherapy demonstrated that low PMN-MDSCs, M-MDSCs, and CD39+ CD8+ T cells as an individual and all together were associated with longer progression free survival and overall survival, suggesting PMN-MDSCs, M-MDSCs, and CD39+ CD8+ T cells frequencies in peripheral blood might be useful as potential predictive and prognostic biomarkers. This article is protected by copyright. All rights reserved.