Requirement of interleukin 17 receptor signaling for lung CXC chemokine and granulocyte colony-stimulating factor expression, neutrophil recruitment, and host …

P Ye, FH Rodriguez, S Kanaly, KL Stocking… - The Journal of …, 2001 - rupress.org
P Ye, FH Rodriguez, S Kanaly, KL Stocking, J Schurr, P Schwarzenberger, P Oliver…
The Journal of experimental medicine, 2001rupress.org
Bacterial pneumonia is an increasing complication of HIV infection and inversely correlates
with the CD4+ lymphocyte count. Interleukin (IL)-17 is a cytokine produced principally by
CD4+ T cells, which induces granulopoiesis via granulocyte colony-stimulating factor (G-
CSF) production and induces CXC chemokines. We hypothesized that IL-17 receptor (IL-
17R) signaling is critical for G-CSF and CXC chemokine production and lung host defenses.
To test this, we used a model of Klebsiella pneumoniae lung infection in mice genetically …
Bacterial pneumonia is an increasing complication of HIV infection and inversely correlates with the CD4+ lymphocyte count. Interleukin (IL)-17 is a cytokine produced principally by CD4+ T cells, which induces granulopoiesis via granulocyte colony-stimulating factor (G-CSF) production and induces CXC chemokines. We hypothesized that IL-17 receptor (IL-17R) signaling is critical for G-CSF and CXC chemokine production and lung host defenses. To test this, we used a model of Klebsiella pneumoniae lung infection in mice genetically deficient in IL-17R or in mice overexpressing a soluble IL-17R. IL-17R–deficient mice were exquisitely sensitive to intranasal K. pneumoniae with 100% mortality after 48 h compared with only 40% mortality in controls. IL-17R knockout (KO) mice displayed a significant delay in neutrophil recruitment into the alveolar space, and had greater dissemination of K. pneumoniae compared with control mice. This defect was associated with a significant reduction in steady-state levels of G-CSF and macrophage inflammatory protein (MIP)-2 mRNA and protein in the lung in response to the K. pneumoniae challenge in IL-17R KO mice. Thus, IL-17R signaling is critical for optimal production of G-CSF and MIP-2 and local control of pulmonary K. pneumoniae infection. These data support impaired IL-17R signaling as a potential mechanism by which deficiency of CD4 lymphocytes predisposes to bacterial pneumonia.
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