Ectopic lymphoid tissue formation in the lungs of mice infected with Chlamydia pneumoniae is associated with epithelial macrophage inflammatory protein-2/CXCL2 expression

• Published in: Clinical and experimental immunology 2010-11, Vol.162 (2), p.372-378
• Main Authors: Fitch, P.M, Wheelhouse, N.M, Bowles, P, Paterson, M, Longbottom, D, Entrican, G, Howie, S.E.M
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Animal Models; Animals; Antibody response; Biological and medical sciences; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - cytology; Bronchoalveolar Lavage Fluid - immunology; Cell Line; Chemokine CXCL2 - genetics; Chemokine CXCL2 - metabolism; Chlamydia; Chlamydia pneumoniae; Chlamydophila Infections - metabolism; Chlamydophila Infections - microbiology; Chlamydophila Infections - pathology; Chlamydophila pneumoniae; Choristoma - immunology; Choristoma - pathology; CXCL2/MIP-2; DNA; DNA, Bacterial - metabolism; Epithelial cells; Epithelial Cells - drug effects; Epithelial Cells - metabolism; epithelium; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Gene Expression - genetics; Helper cells; Immunoglobulin A - immunology; Immunoglobulin A - metabolism; Immunoglobulin G - blood; Immunoglobulin G - immunology; Infections; Inflammation; Inflammation - pathology; Leukocytes (neutrophilic); Lipopolysaccharides; Lipopolysaccharides - immunology; Lipopolysaccharides - pharmacology; Lung; Lung - metabolism; Lung - microbiology; Lung - pathology; Lungs; lymphocytes; Lymphocytes - pathology; Lymphocytes T; Lymphoid tissue; Lymphoid Tissue - immunology; Lymphoid Tissue - pathology; Macrophage inflammatory protein; Mice; Mice, Inbred C57BL; Mucosa; Neutrophilia; Neutrophils - pathology; Pneumonia; Respiratory Mucosa - metabolism; Respiratory Mucosa - pathology; Time Factors
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2010.04231.x

Infection with Chlamydia pneumoniae (Cp) accounts for around 10% of community acquired bacterial pneumonia and has been associated with other chronic inflammatory conditions. We describe a C57/Bl6 murine model of Cp lung infection characterized by a dose-dependent, resolving neutrophilia followed by lymphocytic infiltration of the lungs. By 21 days post-infection, mice exhibit a T helper type 1 (Th1) polarized serum antibody response with local mucosal antibody secretion and organization of ectopic lymphoid tissue which persisted in the absence of detectable Cp DNA. Macrophage inflammatory protein (MIP)-2/CXCL2, which recruits neutrophils and lymphocytes and is associated with ectopic lymphoid tissue formation, was secreted in the lungs post-infection. In vitro, lung epithelial cells up-regulated MIP-2/CXCL2 in response to both rough lipopolysaccharide (reLPS) and Cp infection. We conclude that Cp infection can have long-term inflammatory effects on tissue that persist after clearance of active infection.