Acinetobacter baumannii reinforces the pathogenesis by promoting IL-17 production in a mouse pneumonia model.

Abstract

Interleukin-17 (IL-17) is involved in host defense against bacterial infection. Little is known about the role of IL-17 in A. baumannii-infected pneumonia. Our objective was to investigate the role of IL-17 in pulmonary A. baumannii infection in a mouse model. We infected C57BL/6 mice intra-tracheally (i.t.) with A. baumannii to establish pneumonia model and found A. baumannii infection elevated IL-17 expression in lungs. IL-17-deficient (Il17-/-) mice were resistant to pulmonary A. baumannii infection, showing improved mice survival, reduced bacteria burdens, and alleviated lung inflammation. Further, treatment of A. baumannii-infected Il17-/- mice with IL-17 exacerbated the severity of pneumonia. These data suggest a pathogenic role of IL-17 in pulmonary A. baumannii infection. Further, the infiltration and phagocytic function of neutrophils in broncho-alveolar lavage fluid were detected by flow cytometry. The results showed that Il17-/- mice had increased neutrophil infiltration and enhanced phagocytosis in neutrophils at the early time of infection. Treatment of mice with IL-17 suppressed phagocytic function of neutrophils. All data suggest that IL-17 promotes susceptibility of mice to pulmonary A. baumannii infection by suppressing neutrophil phagocytosis at early time of infection. Targeting IL-17 might be a potential therapeutic strategy in controlling the outcome of A. baumannii pneumonia.

• Authors: Yangyang Zhou, Chuanying Xiang, Ning Wang, Xiaomin Zhang, Yu Xie, Hong Yang, Gang Guo, Kaiyun Liu, Yan Li, Yun Shi
• Journal: Medical microbiology and immunology (Med Microbiol Immunol) Vol. 212 Issue 1 Pg. 65-73 (Feb 2023) ISSN: 1432-1831 [Electronic] Germany
• PMID: 36463365 (Publication Type: Journal Article)
• Copyright: © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Chemical References

• Interleukin-17
• Il17a protein, mouse

Topics

• Animals
• Mice
• Acinetobacter baumannii
• Acinetobacter Infections (microbiology, pathology)
• Disease Models, Animal
• Interleukin-17
• Lung (pathology)
• Mice, Inbred C57BL
• Neutrophils (pathology)
• Pneumonia (pathology)