Figure 4.

Defective IL-1β generation in DPPI^−/− monocytes and neutrophils stimulated with anti-MPO IgG. Murine bone marrow neutrophils (PMN) and monocytes (Mono) were primed with TNFα for 30 minutes and subsequently stimulated with anti-BSA IgG (αBSA) and anti-MPO IgG (αMPO) or left unstimulated (unstim). Supernatants were collected after 4 hours and analyzed for IL-1β by ELISA. Anti-MPO IgG stimulation resulted in robust IL-1β release in WT monocytes (Mono) and to a lesser extent in WT neutrophils (PMN), but release was significantly reduced in cells from DPPI^−/− mice. Two independent experiments using a total of 24 mice were performed. Each experiment used pooled bone marrow neutrophils and bone marrow monocytes from six WT and six DPPI^−/− mice, respectively. *P<0.05.