FIG 4.

Regulatory T cell involvement in the reduction of NK cell cytotoxicity after Pseudomonas aeruginosa infection. Histograms illustrating the percentage of CD4⁺ and CD8⁺ cells among lymphocytes (A), CD4⁺ CD25⁺ cells (B), and CD4⁺ CD25⁺ CD127⁻ cells among CD4⁺ cells (C) in noninfected (NI) or 24-h Pseudomonas aeruginosa-infected (PA) conditions. Histograms illustrating CD107a activity (D) and NKG2D mean fluorescence intensity (MFI) (E) in noninfected (NI) or 24-h Pseudomonas aeruginosa-infected (PA) PBMCs depleted in CD4⁺ CD25⁺ cells before infection (see Fig. SA1 and SA2 in the supplemental material). Data is shown as the median and interquartile range of 4 (A, B, and C) and 5 (D and E) distinct healthy donors. NK cells were analyzed in lymphocyte gate by flow cytometry after PerCp-CD3⁻ APC-CD56⁺ eFluor780⁻ staining. *, P < 0.05; NS, nonsignificant difference; B221, 5-h exposition to B221 cells with a B221/PBMC ratio of 1:1.