Pneumologie 2019; 73(02): 120
DOI: 10.1055/s-0039-1678417
Abstracts
Georg Thieme Verlag KG Stuttgart · New York

CD11b Protects Against Tissue Damage During S. pneumoniae Lung Infection by Limiting Neutrophil Recruitment

Kristina Zec
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
,
Duc Viet Trieu
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
,
Dirk Theegarten
2   Inst. for Pathology, University Hospital Essen
,
Thilo Bracht
3   Cancer Reaserch, ZKF, University Bochum
,
Nirojah Vijitha
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
,
Stephanie Thiebes
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
,
Jenny Bottek
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
,
Daniel Robert Engel
1   Inst. for Immunology and Imaging, Immunodynamics, University Hospital Essen
› Author Affiliations
Further Information

Publication History

Publication Date:
15 February 2019 (online)

 
 

    CD11b is an integrin of the β2 family important for leukocyte adhesion, immunological synapse formation, as well as regulation of signalling from heterologous receptors. Here, we have investigated the role of CD11b in Streptococcus pneumoniae (S. p.) lung infection. We have found that CD11b−/− mice exhibit exacerbated inflammation to S. p. marked by worsened histopathology score, higher levels of pro-inflammatory cytokines and chemokines and increased neutrophil recruitment into the alveolar space. Lung light sheet microscopy revealed increased destruction of alveolar epithelial cells in CD11b−/− mice compared to wt mice. Furthermore, wt alveolar macrophages (AMs) significantly upregulate CD11b upon S. p. infection, suggesting an important function of CD11b in inflammatory AM phenotype. Indeed, CD11b−/− AMs have higher MPO expression and respiratory burst compared to the wt counterparts. AMs isolated from CD11b−/− mice and challenged with S. p. in vitro produce higher levels of pro-inflammatory cytokines and chemokines such as IL-6 and CXCL1 than wt AMs. Our results demonstrate that CD11b protects against tissue damage by limiting AM activation and neutrophil recruitment.


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