Enhanced inflammation in aged mice following infection with Streptococcus pneumoniae is associated with decreased IL-10 and augmented chemokine production.

Am J Physiol Lung Cell Mol Physiol. 2015 Jan 16:ajplung.00141.2014. doi: 10.1152/ajplung.00141.2014. [Epub ahead of print]

Enhanced inflammation in aged mice following infection with Streptococcus pneumoniae is associated with decreased IL-10 and augmented chemokine production.

Williams AE1, José RJ2, Brown JS2, Chambers RC3.

Author information

Abstract

Streptococcus pneumoniae is the most common cause of severe pneumonia in the elderly. However, the impact of ageing on the innate inflammatory response to pneumococci is poorly defined. We compared the innate immune response in old versus young adult mice following infection with S. pneumoniae. The accumulation of neutrophils recovered from bronchoalveolar lavage fluid and lung homogenates was increased in aged compared to young adult mice, although bacterial outgrowth was similar in both age groups, as were markers of microvascular leak. Aged mice had similar levels of IL-1β, TNF, IFN-γ, IL-17 and G-CSF following S. pneumoniae infection, compared to young mice, but increased levels of CXCL9, CXCL12, CCL3, CCL4, CCL5, CCL11 and CCL17. Moreover, levels of IL-10 were significantly lower in aged animals. Neutralization of IL-10 in infected young mice was associated with increased neutrophil recruitment but no decrease in bacterial outgrowth. Furthermore, IL-10 neutralization resulted in increased levels of CCL3, CCL5 and CXCL10. We conclude that ageing is associated with enhanced inflammatory responses following S. pneumoniae infection as a result of a compromised immunomodulatory cytokine response.

Copyright © 2014, American Journal of Physiology - Lung Cellular and Molecular Physiology.

KEYWORDS:

Pneumonia; ageing; chemokine; inflammation; neutrophil

PMID: 25595646 [PubMed - as supplied by publisher]