MCP-1 is critical for early monocyte recruitment and is unaffected by deficient neutrophil recruitment. (A) Time course of cell migration in MCP-1^+/+ (•) and MCP-1^-/- (▴) mice; MCP-1^+/+ and MCP-1^-/- infiltrating cells were compared at each time point (*P ≤ .05). (B) Reduced neutrophil infiltration in LFA-1^-/- () compared with LFA-1^+/+ (□) mice, and further reduction with anti-α4 mAb PS2/3, LFA-1^+/+, and LFA-1^-/- infiltrating cells were compared at each time point (*P ≤ .001). (C) MCP-1 levels in peritoneal lavage of mice (panel B) with blocked neutrophil migration; LFA-1^+/+ and LFA-1^-/- lavages were compared at each time point (P ≥ .05 for all time points). Data shown are representative of 2 or more experiments (means of 4-5 mice per group ±, SEM).