Neutrophils are innate immune cells in chronic inflammatory diseases including chronic obstructive pulmonary disease (COPD) and can be attracted to the site of inflammation via the collagen breakdown product N-acetyl Proline-Glycine-Proline (N-Ac-PGP). To elucidate whether the CXCR2 receptor is involved in N-Ac-PGP-induced neutrophil migration and activation, studies using specific antagonists were performed in vivo. N-Ac-PGP and keratinocyte cell-derived chemokine (KC, CXCL1) were administered in C57Bl/6 mice via oropharyngeal aspiration. Intraperitoneal applications of CXCR2 antagonist SB225002 or SB332235 were administered 1 hour prior and 1 hour after oropharyngeal aspiration. Six hours after oropharyngeal aspiration mice were sacrificed. Neutrophil counts and CXCL1 levels were determined In bronchoalveolar lavage fluid, myleoperoxidase (MPO) levels were measured in lung tissue homogenates and an immunohistological staining for neutrophils was performed on lung tissue. N-Ac-PGP and CXCL1 induced a neutrophil influx in the bronchoalveolar lavage fluid and lung tissue, which was also reflected by increased MPO levels in lung tissue. The N-Ac-PGP- and CXCL1-induced neutrophil influx and the increased pulmonary tissue MPO levels were inhibited by the CXCR2 antagonists SB225002 and SB332235. Moreover, N-Ac-PGP administration enhanced the CXCL1 levels in bronchoalveolar lavage fluid, which could not be attenuated by both CXCR2 antagonists. It can be concluded that neutrophil migration induced by N-Ac-PGP is mediated via direct interaction with CXCR2 or indirectly via the release of CXCL1. The N-Ac-PGP-induced release of CXCL1 is independent of the CXCR2 receptor. Furthermore, N-Ac-PGP is more potent in inducing the neutrophil migration in the pulmonary tissue than into the bronchoalveolar lavage fluid.