Fig. 1From: Differences in systemic adaptive immunity contribute to the ‘frequent exacerbator’ COPD phenotypeGating strategy for adaptive immune cells. Lymphocytes were gated based on their characteristic scatter patterns. Lymphocytes were then classified based on CD3 expression to identify T cells, which were divided into CD4+ and CD8+ T cells, prior to separation into their four main subsets of naive, central memory (Tcm), effector memory (Tem), and end-stage T cells (Tend); this separation was based on the expression of CD45R0 and CD62L. Tcm cells: CD45R0+/CD62L+, Tem cells: CD45R0+/CD62-, Naive T cells: CD45R0-/CD62L+, and Tend cells: CD45R0-/CD62L-. The CD4+ and CD8+ T cells were subsequently analysed (including each of the main subsets) for expression of the markers CD127, HLA-DR, CD25 and PD-1. Regulatory T-cells were identified based on the high expression of CD25 and low expression of CD127 in CD4+ T cellsBack to article page