Figure 6.

Influence of BPI on TNFα secretion of PBMCs in response to bLPs and lysates of S. pneumoniae D39Δcps. TNFα-ELISA of the supernatants of PBMCs stimulated with TLR-ligands [LPS EC, (R)-Pam₃CSK₄ or (R)-FSL-1] ± rBPI at the indicated concentrations for 18 h (A). Independent titration experiments performed in four different donors are indicated as relative increase compared to cytokine secretion with TLR ligand alone (A). The relative increase in TNFα, IL-6, and IL-8 in the supernatants of PBMCs stimulated with (R)-Pam₃CSK₄ ± rBPI is represented (C). One donor (•) is not shown in (C) for stimulation since IL-6 was beyond the linear range of the ELISA. The relative increase in TNFα in the supernatants of PBMCs stimulated with (R)-Pam₃CSK₄ ± BPI_N(A) or LTA SP ± rBPI is summarized (B,D). PBMCs were stimulated with lysates of S. pneumoniae D39Δcps and S. aureus 113 and the relative change in secreted TNFα, IL-6, and IL-8 caused by the addition of BPI is shown (E,F). Results of independent stimulations of PBMCs of four (A,D) or seven (B,C,E,F) different donors are shown. Each symbol represents an individual donor (B–F). Unless otherwise indicated, the BPI concentration used was 500 nM. Statistics for comparison of the relative cytokine secretion ± BPI were performed with the paired Student's t-test (p-values are indicated, B–F). Results are shown as means ± SEM (A).