Effects of blockade of KC, MIP-2, or CXCR2 on neutrophil numbers in BAL fluid. Five mice were injected i.p. with anti-KC antibody, anti–MIP-2 serum, anti-KC antibody plus anti–MIP-2 serum, anti-CXCR2 serum, or control serum (normal rabbit serum or normal goat serum) 2 h before infection. Neutrophil numbers in BAL fluid were determined 2 days after infection. An asterisk indicates a P value of < 0.05. Data are means and standard deviations.