Figure 5

Monocytes recruited into the lungs in response to intraperitoneal LPS do not enhance but rather decrease neutrophilic alveolitis in mice challenged with CCL2 plus LPS. (A) Treatment groups of experiments shown in (B). Mice were either left untreated (bar 1) or received LPS intraperitoneally for 96 h (bar 2) or received intratracheal LPS applications alone for 24 h (bar 3) (1 μg/mouse). In addition, groups of mice received either combined intraperitoneal LPS applications (50 μg/mouse) and 96 h later, an intratracheal LPS application for 24 h (1 μg/mouse) (bar 4) or combined intratracheal applications of CCL2 for 48 h (50 μg/mouse) plus LPS for 24 h (1 μg/mouse) (bar 6) or were pretreated with intraperitoneal LPS for 48 h, followed by instillation of CCL2 (50 μg/mouse) for another 48 h followed by an intratracheal LPS application for 24 h (bar 5). Subsequently, mice were sacrificed and total numbers of alveolar recruited neutrophils were calculated. Values are given as mean ± SEM of at least five mice per treatment group. * indicates p < 0.01 versus control, + indicates p < 0.01 compared to all other treatment groups.