Fig. 1

Intracellular cytokine expression by T lymphocytes isolated from COPD patients and controls. Flow cytometry analysis of intracellular cytokine expression (IFN-γ, IL-4 and IL-17A) was performed after anti-CD3/CD28 stimulation of CD4⁺ T-cells or CD8⁺ T-cells sorted from PBMC isolated from COPD patients (n = 29) and controls (n = 13). The plots show sequentially the gating hierarchy of one representative sample: live cells, CD2⁺ T-cells and subsequently activated CD25⁺ CD8⁺ T-cells or activated CD25⁺ CD4⁺ T-cells. The plots on the lowest rows include the cytokine expression gates for either CD8⁺ T-cells or CD4⁺ T-cells. Fluorescence minus one control condition, in which the antibody conjugate in question is omitted, is used to guide creation of the gate that defines positive expression of that target. A total of 20,000 CD4⁺ T-cell events or 20,000 CD8⁺ T-cell events were acquired per sample. Values are expressed as percentage of activated CD4⁺ CD25⁺ or CD8⁺ CD25⁺ T cells expressing each cytokine. *p < 0.05