Dipeptidyl peptidase I activates neutrophil-derived serine proteases and regulates the development of acute experimental arthritis
J. Clin. Invest. April M. Adkison, et al. 109:363 doi:10.1172/JCI13462 [Go to this article.]

Figure 4
In vitro neutrophil degranulation and TNF-α production in DPPI^–/– mice. (a) Purified PMNs (10⁷/ml) were incubated with 50 ng/ml PMA for 15 minutes, and cell-free supernatants were analyzed by gelatin zymography. Note that DPPI^–/– and WT PMNs released equivalent levels of MMP-9. (b) TNF-α production 90 minutes after intraperitoneal injection of 100 μg LPS. Open circles represent TNF-α levels prior to LPS injection. Serum TNF-α levels (filled circles) after LPS injection were equivalent in WT mice and DPPI^–/– mice.