Peripheral circulating Ts (CD8+CD28-)/CD8+is elevated in non small cell lung cancer patients

Antitumor immune response is usually inhibited by immunosuppressive tumor microenvironment. CD8+CD28-T lymphocyte (Ts; or CD8+ Treg) is another regulatory T cell apart from CD4+CD25highCD127low Treg, and it has been detected infiltrating in tumor tissue of various types as well. The aim of this study is to investigate possible role of both Tregs in peripheral circulation of non small cell lung cancer (NSCLC) patients. Twenty-eight eligible NSCLC patients pariticipated this study, and 17 healthy volunteers plus 1 patient of pulmonary bulla and 2 patients of congenital chest wall deformity were also included in this study as control group. Peripheral circulating CTL (CD8+CD28+)/CD8+, Ts or CD8+ Treg (CD8+ CD28-)/CD8+, CD4+ Treg (CD4+CD25highCD127low/CD4+ were assayed by Flow Cytometry. We observed that Ts (CD8+ CD28-)/CD8+ in NSCLC group is significantly higher than that in control group (P=0.0056). CTL (CD8+CD28+)/CD8+ in NSCLC group is significantly lower than that in control group (P=0.0013). CD4+ Treg (CD4+ CD25highCD127low)/CD4+ in NSCLC group is not significantly different from that in control group (P=0.8689). In conclusion, Ts (CD8+ Treg) instead of CD4+ Treg might be an immunosuppressive factor in peripheral circulation of NSCLC patients.