Fig. 1

Gating strategy. A Gating strategy to identify peripheral blood CD4 T cells, classical CD8 T cells, MAIT cells and expression of the activation markers CD38 and LAG-3 on MAIT cells. Gates for CD38 and LAG-3 expression on MAIT cells (orange) were set based on the expression on total T cells (in grey) when a clear negative and positive population could be identified or based on the unstained control (black) otherwise. MAIT cells were identified as CD4-Vα7.2 + CD161 + T cells. For quantification of classical CD8 T cells, MAIT cells were gated out. B Phenotypic comparison of MAIT cells in COPD patients requiring hospitalization or not during the 3-year follow-up. Representative flow cytometry staining of TIM-3, PD1, HLA-DR, CD56, CCR5 and TIGIT on MAIT cells (orange) using the unstained control (black) or the total T cells (grey) as controls to set the gate. The scatter plots display the expression of each marker (median ± IQR) on MAIT cells between Hospitalized (n = 21) and Never Hospitalized (n = 40) COPD patients during the 3-year follow-up. The Mann–Whitney U Test was used to evaluate statistical differences between groups