Kinetics of DC activation upon administration of LPS and anti-CD40 antibody. Eight- to 10-week-old C57BL/6 mice (n = 4 per cohorts) received LPS (100 μg/mouse) plus anti-CD40 antibody (100 μg/mouse; red line), or anti-CD40 antibody alone (blue line), or PBS (green line). Cells from draining lymph nodes (A) and splenocytes (B) were collected at 6, 24, 72, and 120 hours after injection and stained for cell surface antigens of CD11c (top panel), CD80 (middle panel), and CD86 (bottom panel). The cells were first gated on the CD11c⁺ population of live cells. Expression of CD80 and CD86 was determined from the gated CD11c population. A representative of 2 independent experiments for each time point is shown.