Pneumolysin induces release of matrix metalloproteinase-8 and -9 from human neutrophils

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Colleges, School and Institutes


The research question addressed in the current study was: does the pneumococcal pore-forming toxin, pneumolysin, mobilise matrix metalloproteinase (MMP) -8 and -9 from isolated human blood neutrophils at sublytic concentrations of 5, 10 and 20 ng.mL(-1)? MMPs were measured in the supernatants of unstimulated neutrophils and of cells exposed to pneumolysin and the chemoattractant N-formyl-L-methionyl-l-leucyl-l-phenylalanine (f-MLP; 0.1 microM), individually and in combination, using ELISA procedures, and alterations in cytosolic Ca(2+) concentrations were monitored using a fura-2 acetoxymethyl ester (fura-2/AM)-based spectrofluorimetric method. Treatment of neutrophils with pneumolysin alone caused dose-related release of both MMPs, whereas f-MLP caused modest increases; the combination of both activators was, however, most effective. Pneumolysin/f-MLP-activated release of the MMPs from the cells was paralleled by increases in cytosolic Ca(2+). Exposure of human neutrophils to pneumolysin is accompanied by mobilisation of MMPs, which is potentiated by f-MLP. If operative in vivo, pneumolysin-mediated release of MMPs from neutrophils and other cell types may contribute to the pathogenesis of severe pneumococcal disease.


Original languageEnglish
Pages (from-to)1167-70
Number of pages4
JournalThe European respiratory journal
Issue number5
Publication statusPublished - Nov 2009


  • Bacterial Proteins, Calcium, Chemotactic Factors, Cytosol, Enzyme-Linked Immunosorbent Assay, Fura-2, Humans, Inflammation, Matrix Metalloproteinase 8, Matrix Metalloproteinase 9, N-Formylmethionine Leucyl-Phenylalanine, Neutrophils, Spectrometry, Fluorescence, Streptolysins