title: Trogocytosis-associated cell to cell spread of intracellular bacterial pathogens.
abstract: Macrophages are myeloid-derived phagocytic cells and one of the first immune cell types to respond to microbial infections. However, a number of bacterial pathogens are resistant to the antimicrobial activities of macrophages and can grow within these cells. Macrophages have other immune surveillance roles including the acquisition of cytosolic components from multiple types of cells. We hypothesized that intracellular pathogens that can replicate within macrophages could also exploit cytosolic transfer to facilitate bacterial spread. We found that viable Francisella tularensis, as well as Salmonella enterica bacteria transferred from infected cells to uninfected macrophages along with other cytosolic material through a transient, contact dependent mechanism. Bacterial transfer occurred when the host cells exchanged plasma membrane proteins and cytosol via a trogocytosis related process leaving both donor and recipient cells intact and viable. Trogocytosis was strongly associated with infection in mice, suggesting that direct bacterial transfer occurs by this process in vivo.
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, United States.
authors.forename: Shaun
authors.initials: S
authors.lastname: Steele
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, United States.
authors.forename: Lauren
authors.initials: L
authors.lastname: Radlinski
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, United States.
authors.forename: Sharon
authors.initials: S
authors.lastname: Taft-Benz
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, United States.
authors.forename: Jason
authors.initials: J
authors.lastname: Brunton
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, United States.
authors.forename: Thomas H
authors.identifier: http://orcid.org/0000-0001-7526-5159
authors.initials: TH
authors.lastname: Kawula
mesh_terms: D000818:Animals; D002450:Cell Communication; D002460:Cell Line; D003593:Cytoplasm / Q000382:microbiology*; D004847:Epithelial Cells / Q000382:microbiology / Q000502:physiology; D005604:Francisella tularensis / Q000302:isolation & purification*; D054992:Immunological Synapses / Q000382:microbiology*; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology*; D051379:Mice; D019779:Salmonella enterica / Q000302:isolation & purification*
keywords: cell to cell spread; francisella tularensis; immunology; infectious disease; microbiology; mouse; salmonella typhimurium; trogocytosis