FIG 1.

E. chaffeensis blocks PMA-induced ROS generation by WT BMDM but not by CD147^–/– BMDM. BMDM from WT mice (A and B) or CD147^–/– mice (C and D) were preincubated with luminol in HBSSd for 15 min and then incubated with E. chaffeensis (Ech) isolated from infected DH82 cells, DH82 cell lysate, or HBSSd (control [CTL]) at 37°C for 30 min. ROS generation was continuously recorded as the relative chemiluminescence of oxidized luminol after the addition of PMA (200 nM, indicated by arrows) (A and C). UN, unstimulated BMDM in HBSSd without PMA addition. The area under the curve was measured over 60 min after PMA addition and is shown relative to ROS generation in the control with PMA, which was considered 100% in panels B and D. Results represent the means plus standard deviations (SD) (error bars) from at least three independent experiments and were compared by Student’s t test. Values that are significantly different (P < 0.05) are indicated by a bar and asterisk.