Figure 3

Representative flow cytometry plot (Panel A) showing the expression of both granzyme B and perforin (Panel B) in CD88 ⁺ T lymphocytes, CD56 ^dim CD16 ⁺ NK cells, CD56 ^bright CD16 ^- NK cells and NKT-like (CD56 ⁺ CD3 ⁺ ) cells from non-smoking healthy participants (n = 12), healthy smokers (n = 15) and smokers with COPD (n = 10). Double stained cells (Panel B) are deemed cytotoxic (**; p < 0.01).