Interference with the oxidative response of neutrophils by Streptococcus pneumoniae
| Autor: | L W Greenham, J R Catterall, C J Elson, F E Perry |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Pulmonary and Respiratory Medicine
Autolysis (biology) Neutrophils Neutrophile Biology medicine.disease_cause Microbiology chemistry.chemical_compound Superoxides Streptococcus pneumoniae medicine Humans Respiratory Burst chemistry.chemical_classification Reactive oxygen species Superoxide medicine.disease Streptococcaceae biology.organism_classification Respiratory burst respiratory tract diseases chemistry Pneumococcal pneumonia Immunology Tetradecanoylphorbol Acetate Research Article |
| Zdroj: | Thorax. 48(4) |
| ISSN: | 0040-6376 |
| Popis: | BACKGROUND--Pneumococcal infections are still a major clinical problem. Polymorphonuclear leucocytes (neutrophils) are considered to have a key role in the host's defence against Streptococcus pneumoniae but the mechanisms by which they kill the pneumococcus remain unclear. As reactive oxygen species are regarded as a major antimicrobial defence of phagocytes an attempt has been made to establish their role in the response of neutrophils to S pneumoniae. METHODS--S pneumoniae isolated from patients with bacteraemic pneumococcal pneumonia were incubated with neutrophils in suspension and superoxide production was measured by reduction of ferricytochrome c. RESULTS--S pneumoniae did not stimulate superoxide production alone or in the presence of normal human serum. Spontaneous superoxide production by neutrophils was actually abrogated by S pneumoniae, as was the powerful respiratory burst stimulated by phorbol myristate acetate. This phenomenon depended on both the dose and the viability of the bacteria. With S pneumoniae in the logarithmic phase of growth inhibitory activity was confined to the organisms themselves but with organisms undergoing autolysis it was also present in filtered supernatants, suggesting that the inhibitory activity can be attributed to a factor released during autolysis. CONCLUSIONS--S pneumoniae can interfere with the respiratory burst of neutrophils. This property may help to explain the pathogenicity of the organism. |
| Databáze: | OpenAIRE |
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