Effect of Alpha-1-Proteinase Inhibitor on... : American Journal of Respiratory Cell and Molecular Biology (original) (raw)

Effect of Alpha-1-Proteinase Inhibitor on Neutrophil Chemotaxis

American Journal of Respiratory Cell and Molecular Biology

2

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163

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170

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February 1990

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| DOI: 10.1165/ajrcmb/2.2.163

Factors that modulate neutrophil migration into the lung are poorly understood. However, there is evidence that neutrophil activation by formylmethionylleucylphenylalanine (FMLP) depends upon a surface proteinase with chymotrypsin-like activity. This suggests that chymotrypsin inhibitors such as alpha-1-proteinase inhibitor (_α_1PI) could modify neutrophil migration in response to FMLP.

We have studied neutrophil Chemotaxis using the multiple blind well assay system. This article presents evidence that _α_1PI is an inhibitor of neutrophil migration in response to FMLP. The effect is related to the inhibitory function of the protein. Alpha-1-antichymotrypsin is more potent than _α_1PI as an inhibitor of this movement, whereas antileukoprotease is less potent. The results suggest that a cell membrane-bound serine proteinase (perhaps cathepsin G) is necessary for the enhancement of cell movement after receptor binding of FMLP. Oxidized _α_1PI or a 4,000-D peptide cleaved from _α_1PI by porcine pancreatic elastase or human neutrophil elastase are capable of enhancing cell motility. The results suggest that _α_1PI may play a role in cell migration into the lung during acute inflammatory process.