title: Chlamydia trachomatis Cellular Exit Alters Interactions with Host Dendritic Cells.
abstract: The strategies utilized by pathogens to exit host cells are an area of pathogenesis which has received surprisingly little attention, considering the necessity of this step for infections to propagate. Even less is known about how exit through these pathways affects downstream host-pathogen interactions and the generation of an immune response.Chlamydia trachomatisexits host epithelial cells through two equally active mechanisms: lysis and extrusion. Studies have characterized the outcome of interactions between host innate immune cells, such as dendritic cells and macrophages, and free, extracellularChlamydiabacteria, such as those resulting from lysis. Exit via extrusion generates a distinct, host-membrane-bound compartment ofChlamydiaseparate from the original infected cell. In this study, we assessed the effect of containment within extrusions upon the interaction betweenChlamydiaand host dendritic cells. Extrusion dramatically affected the outcome ofChlamydia-dendritic cell interactions for both the bacterium and the host cell. Dendritic cells rapidly underwent apoptosis in response to engulfment of an extrusion, while uptake of an equivalent dose of freeChlamydiahad no such effect. Containment within an extrusion also prolonged bacterial survival within dendritic cells and altered the initial innate immune signaling by the dendritic cell.
authors.affiliation: Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Sherrid
authors.affiliation: Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA khybiske@uw.edu.
authors.forename: Kevin
authors.identifier: http://orcid.org/0000-0002-2967-3079
authors.initials: K
authors.lastname: Hybiske
mesh_terms: D000818:Animals; D017209:Apoptosis; D002470:Cell Survival; D002478:Cells, Cultured; D002692:Chlamydia trachomatis / Q000472:pathogenicity*; D003713:Dendritic Cells / Q000276:immunology* / Q000382:microbiology*; D005347:Fibroblasts / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D008810:Mice, Inbred C57BL; D050296:Microbial Viability
keywords: Chlamydia; apoptosis; dendritic cell; extrusion