Proinflammatory interactions of pneumolysin with human neutrophils

Research output: Contribution to journalArticlepeer-review


  • R Cockeran
  • A J Theron
  • H C Steel
  • N M Matlola
  • C Feldman

Colleges, School and Institutes


The effects of pneumolysin on the proinflammatory activity of human neutrophils, as well as on cation fluxes in these cells, have been investigated. Superoxide production, release of elastase, CR3 expression, phospholipase A2 activity, and alterations in membrane potential were measured by use of lucigenin-enhanced chemiluminescence and colorimetric, flow cytometric, radiometric, and spectrofluorimetric procedures, respectively; and cation fluxes were measured by use of 45Ca2+ and 86Rb+ and by fura-2 spectrofluorometry. Pneumolysin at concentrations >1.67 ng/mL caused influx of Ca2+ and increased phospholipase A2 activity and CR3 expression, which were associated with enhanced superoxide production and release of elastase after activation of the cells with the chemotactic tripeptide FMLP. At the same concentrations, pneumolysin caused efflux of K+ and membrane depolarization. The effects of pneumolysin on cation fluxes were not attributable to inhibition of Ca2+-adenosine triphosphatase (ATPase) or Na+, K+-ATPase. Pneumolysin potentiates the proinflammatory activities of neutrophils by a pore-forming mechanism resulting in Ca2+ influx.


Original languageEnglish
Pages (from-to)604-11
Number of pages8
JournalThe Journal of Infectious Diseases
Issue number4
Publication statusPublished - 15 Feb 2001


  • Adenosine Triphosphate, Bacterial Proteins, Calcium, Calcium-Transporting ATPases, Cell Degranulation, Escherichia coli, Humans, Inflammation, Macrophage-1 Antigen, Membrane Potentials, Neutrophils, Pancreatic Elastase, Phospholipases A, Phospholipases A2, Potassium, Recombinant Proteins, Sodium-Potassium-Exchanging ATPase, Streptolysins, Superoxides