CF but not COPD monocytes fail to induce TREM-1 expression after LPS stimulation.

<p>(A) Cultures of human monocytes from healthy volunteers (control, gray bars, n = 10) CF patients (CF, solid bars, n = 20) and COPD patients (COPD, hatched bars, n = 10) were treated with 10 ng/ml LPS for indicated times. Next, cells were harvested and stained with anti-TREM-1-FITC and analyzed by flow cytometry. The fraction of positive cells is given as % of total cells (A) and MFIs (B). The percentage of CD14 and TREM-1 positive cells was analyzed in monocytes from five of each of the studied groups (i.e., CF patients, COPD patients and healthy individuals; all samples were randomly selected), treated or not <i>ex vivo</i> with LPS for 1 hour. The flow cytometry analysis of these cells simultaneously stained with CD14-APC and TREM-1-FITC is shown (C). Supernatants from the same experiment (shown in panels A and B) were centrifuged at 400×g to remove detached cells and possible cellular debris. The concentration of sTREM-1 in the supernatants was analyzed with a commercial ELISA. The mean concentration of sTREM-1 in ng/ml is given (D). *, p<0.05 and **, p<0.01 with respect to similarly treated monocytes from healthy individuals.