Abstract
Immune responses to pathogens occur within the context of current and previous infections. Cross protection refers to the phenomena where infection with a particular pathogen provides enhanced resistance to a subsequent unrelated pathogen in an antigen-independent manner. Proposed mechanisms of antigen-independent cross protection have involved the secretion of IFN-γ, which activates macrophages, thus providing enhanced innate immunity against the secondary viral or bacterial pathogen. Here we provide evidence that a primary infection with the chronic respiratory pathogen, Mycoplasma pulmonis, provides a novel form of cross protection against a secondary infection with Listeria monocytogenes that is not mediated by IFN-γ, but instead relies upon IL-17 and mobilization of neutrophils. Mice infected with M. pulmonis have enhanced clearance of L. monocytogenes from the spleen and liver, which is associated with increased numbers of Gr-1+CD11b+ cells and higher levels of IL-17. This enhanced clearance of L. monocytogenes was absent in mice depleted of Gr-1+ cells or in mice deficient in the IL-17 receptor. Additionally, both the IL-17 receptor and neutrophils were essential for optimal clearance of M. pulmonis. Tbus, a natural component of the immune response directed against M. pulmonis was able to enhance clearance of L. monocytogene.
Original language | English |
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Pages (from-to) | 426-438 |
Number of pages | 13 |
Journal | European Journal of Immunology |
Volume | 39 |
Issue number | 2 |
DOIs | |
State | Published - 2009 |
Keywords
- Bacterial infection
- Cytokine
- Cytokine receptor
- Neutrophil