Neutrophils play an ongoing role in preventing bacterial pneumonia by blocking the dissemination of S. aureus from the upper to the lower airways.
2020
Staphylococcus aureus is found in the nasal cavity of up to 30% of the human population. Persistent nasal carriage of S. aureus is a risk factor for influenza virus induced secondary bacterial pneumonia. To date, there is limited understanding of the factors that cause S. aureus to shift from the upper to the lower respiratory tract and convert from a commensal organism to an invasive pathogen. Here we show that neutrophils actively prevent S. aureus dissemination. Establishment of a mouse model of localised S. aureus nasal carriage revealed variations in the longevity of persistence of S. aureus isolates. Improved persistence within this site was associated with reduced nasal inflammation, less neutrophil egress into the airways and reduced neutrophil-bacteria association. Neutrophil depletion of mice with localised S. aureus nasal carriage triggered the development of an invasive S. aureus infection. Moreover, utilizing a model of influenza induced staphylococcal pneumonia we showed that treatment with granulocyte-colony stimulating factor (G-CSF), a potent enhancer of neutrophil number and function, significantly reduced bacterial loads in the lung and improved disease outcomes. This data reveals that neutrophils play an important and active role in confining S. aureus to the upper respiratory tract and highlights the use of approaches that improve neutrophil function as effective strategies to attenuate morbidity associated with staphylococcal pneumonia.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
74
References
5
Citations
NaN
KQI