Mediastinal lymph node removal ameliorates cytotoxic T-lymphocyte functions in patients with non-small cell lung cancer

Abstract

Introduction: Mediastinal lymph node (MLN) removal by video-assisted mediastinoscopic lymphadenectomy (VAMLA) for preoperative cancer staging was reported to be associated with increased survival. The aim of this study was to evaluate the immunologic effects of complete MLN removal by VAMLA on cytotoxic T lymphocyte (CTL) phenotype and function. Methods: Seventeen patients with non-small cell lung cancer (NSCLC) (stage cT1-4N0-3M0-1A) and 20 healthy participants were included in this study. Blood samples were collected before and 4 weeks after the procedure. Lymphocytes were isolated from the removed MLNs. CTL phenotypes and functions were evaluated by flow cytometry. Plasma levels of soluble programmed cell death protein 1 (sPD-1), soluble programmed cell death protein 1 ligand, and soluble CTL antigen 4 (sCTLA-4) were measured with enzyme-linked immunosorbent assay. Results: The ratio of the immunosenescent CTLs (CD3+CD8+CD28−) was increased in peripheral blood and MLNs of the patients with NSCLC compared to controls ( p = 0.037), and MLN removal did not change this ratio. PD-1 and CTL antigen 4 expressions were significantly reduced in peripheral blood CTLs after MLN removal by VAMLA ( p = 0.01 and p = 0.01, respectively). Granzyme A expression was significantly reduced in the peripheral blood CTLs of the patients compared to controls ( p = 0.006) and MLN removal by VAMLA significantly improved Granzyme A expression in CTLs ( p = 0.003). Plasma concentrations of sPD-1 and sCTLA-4 remained unchanged after VAMLA. Conclusion: CTLs in the MLNs and peripheral blood of the patients with NSCLC had an immunosenescent phenotype, increased immune checkpoint receptor expression, and impaired cytotoxicity. MLN removal by VAMLA improved these phenotypic and functional characteristics of CTLs. These changes may explain the potential contribution of VAMLA to improved survival.

Advances in lymphatic metastasis of non-small cell lung cancer

“…Removal of the mediastinal lymph nodes (MLN) increased the anti-tumoral activity of NK cell and reversed its exhaustion [ 113 ]. Meanwhile, MLN removal could improve immunosenescent phenotype, immune checkpoint receptor expression, and cytotoxicity by CTLs [ 114 ].…”

The importance of alterations in innate lymphoid cell subsets in patients with non-small cell lung cancer and their role in tumorigenesis

“…To isolate mononuclear cells, cell suspension was centrifuged by the Ficoll-Hypaque gradient and centrifuged at 800xg for 20 minutes. 16 After centrifugation, lymphocyte-rich mononuclear layer was collected. The washing process was repeated two times then the cells were re-suspended in a complete RPMI-1640 culture medium.…”