title: Cryptococcal transmigration across a model brain blood-barrier: evidence of the Trojan horse mechanism and differences between Cryptococcus neoformans var. grubii strain H99 and Cryptococcus gattii strain R265.
abstract: Cryptococcus neoformans (Cn) and Cryptococcus gattii (Cg) cause neurological disease and cross the BBB as free cells or in mononuclear phagocytes via the Trojan horse mechanism, although evidence for the latter is indirect. There is emerging evidence that Cn and the North American outbreak Cg strain (R265) more commonly cause neurological and lung disease, respectively. We have employed a widely validated in vitro model of the BBB, which utilizes the hCMEC/D3 cell line derived from human brain endothelial cells (HBEC) and the human macrophage-like cell line, THP-1, to investigate whether transport of dual fluorescence-labelled Cn and Cg across the BBB occurs within macrophages. We showed that phagocytosis of Cn by non-interferon (IFN)-γ stimulated THP-1 cells was higher than that of Cg. Although Cn and Cg-loaded THP-1 bound similarly to TNF-activated HBECs under shear stress, more Cn-loaded macrophages were transported across an intact HBEC monolayer, consistent with the predilection of Cn for CNS infection. Furthermore, Cn exhibited a higher rate of expulsion from transmigrated THP-1 compared with Cg. Our results therefore provide further evidence for transmigration of both Cn and Cg via the Trojan horse mechanism and a potential explanation for the predilection of Cn to cause CNS infection.
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia. Electronic address: tania.sorrell@sydney.edu.au.
authors.forename: Tania C
authors.initials: TC
authors.lastname: Sorrell
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia; Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Westmead 2145, Australia; Vascular Immunology Unit, Department of Pathology, School of Medical Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Pierre-Georges
authors.initials: PG
authors.lastname: Juillard
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia; Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Westmead 2145, Australia.
authors.forename: Julianne T
authors.initials: JT
authors.lastname: Djordjevic
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia; Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, Westmead 2145, Australia.
authors.forename: Keren
authors.initials: K
authors.lastname: Kaufman-Francis
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria; Vascular Immunology Unit, Department of Pathology, School of Medical Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Anelia
authors.initials: A
authors.lastname: Dietmann
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria; Vascular Immunology Unit, Department of Pathology, School of Medical Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Alban
authors.initials: A
authors.lastname: Milonig
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia; Vascular Immunology Unit, Department of Pathology, School of Medical Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Valery
authors.initials: V
authors.lastname: Combes
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney and Westmead Millennium Institute for Medical Research, Westmead, NSW 2145, Australia; Vascular Immunology Unit, Department of Pathology, School of Medical Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Georges E R
authors.initials: GE
authors.lastname: Grau
mesh_terms: D001812:Blood-Brain Barrier / Q000382:microbiology*; D002465:Cell Movement; D002478:Cells, Cultured; D056285:Cryptococcus gattii / Q000502:physiology*; D003455:Cryptococcus neoformans / Q000502:physiology*; D042783:Endothelial Cells / Q000502:physiology; D006801:Humans; D008264:Macrophages / Q000382:microbiology*; D008954:Models, Biological
keywords: Brain endothelium; Cryptococcus; Monocytes; Phagocytosis; Transmigration