title: Dendritic cells from aged subjects display enhanced inflammatory responses to Chlamydophila pneumoniae.
abstract: Chlamydophila pneumoniae (CPn) is a common respiratory pathogen that causes a chronic and persistent airway infection. The elderly display an increased susceptibility and severity to this infection. However, the underlying mechanisms are not well understood. Dendritic cells (DCs) are the initiators and regulators of immune responses. Therefore, we investigated the role of DCs in the age-associated increased CPn infection in vitro in humans. Though the expression of activation markers was comparable between the two age groups, DCs from aged subjects secreted enhanced levels of proinflammatory mediators such as TNF-α and CXCL-10 in response to CPn. In contrast, the secretion of IL-10 and innate interferons, IFN-α and IFN-λ, was severely impaired in DCs from aged donors. The increased activation of DCs from aged subjects to CPn also resulted in enhanced proliferation of CD4 and CD8 T cells in a DC-T coculture. Furthermore, T cells primed with CPn-stimulated DCs from aged subjects secreted increased levels of IFN-γ and reduced levels of IL-10 compared to DCs obtained from young subjects. In summary, DCs from the elderly displayed enhanced inflammatory response to CPn which may result in airway remodeling and increase the susceptibility of the elderly to respiratory diseases such as asthma.
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Prakash
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Sudhanshu
authors.initials: S
authors.lastname: Agrawal
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Dandan
authors.identifier: 0000-0002-3380-5249
authors.initials: D
authors.lastname: Ma
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Pathology and Laboratory Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Ellena M
authors.initials: EM
authors.lastname: Peterson
authors.affiliation: Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
authors.forename: Anshu
authors.identifier: 0000-0002-3323-9152
authors.initials: A
authors.lastname: Agrawal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D003713:Dendritic Cells / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055815:Young Adult