title: Interactions between brain endothelial cells and human T-cell leukemia virus type 1-infected lymphocytes: mechanisms of viral entry into the central nervous system.
abstract: Human T-cell leukemia virus type 1 (HTLV-1) is associated with a variety of clinical manifestations, including tropical spastic paraparesis or HTLV-1-associated myelopathy (TSP/HAM). Viral detection in the central nervous system (CNS) of TSP/HAM patients demonstrates the ability of HTLV-1 to cross the blood-brain barrier (BBB). To investigate viral entry into the CNS, rat brain capillary endothelial cells were exposed to human lymphocytes chronically infected by HTLV-1 (MT2), to lymphocytes isolated from a seropositive patient, or to a control lymphoblastoid cell line (CEM). An enhanced adhesion to and migration through brain endothelial cells in vitro was observed with HTLV-1-infected lymphocytes. HTLV-1-infected lymphocytes also induced a twofold increase in the paracellular permeability of the endothelial monolayer. These effects were associated with an increased production of tumor necrosis factor alpha by HTLV-1-infected lymphocytes in the presence of brain endothelial cells. Ultrastructural analysis showed that contact between endothelial cells and HTLV-1-infected lymphocytes resulted in a massive and rapid budding of virions from lymphocytes, followed by their internalization into vesicles by brain endothelial cells and apparent release onto the basolateral side, suggesting that viral particles may cross the BBB using the transcytotic pathway. Our study also demonstrates that cell-cell fusion occurs between HTLV-1-infected lymphocytes and brain endothelial cells, with the latter being susceptible to transient HTLV-1 infection. These aspects may help us to understand the pathogenic mechanisms associated with neurological diseases induced by HTLV-1 infection.
authors.affiliation: CNRS UPR 0415, Institut Cochin de Génétique Moléculaire, 75014 Paris, France. i.romero@open.ac.uk
authors.forename: I A
authors.initials: IA
authors.lastname: Romero
authors.forename: M C
authors.initials: MC
authors.lastname: Prevost
authors.forename: E
authors.initials: E
authors.lastname: Perret
authors.forename: P
authors.initials: P
authors.lastname: Adamson
authors.forename: J
authors.initials: J
authors.lastname: Greenwood
authors.forename: P O
authors.initials: PO
authors.lastname: Couraud
authors.forename: S
authors.initials: S
authors.lastname: Ozden
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000821:virology; D002196:Capillaries / Q000166:cytology; D002448:Cell Adhesion / Q000502:physiology; D002459:Cell Fusion; D002463:Cell Membrane Permeability; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D002490:Central Nervous System / Q000098:blood supply / Q000821:virology; D018920:Coculture Techniques; D004705:Endocytosis; D004730:Endothelium, Vascular / Q000166:cytology / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D006801:Humans; D039041:Integrin alpha4beta1; D016023:Integrins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D051379:Mice; D051381:Rats; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism; D013601:T-Lymphocytes / Q000502:physiology / Q000821:virology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D014771:Virion
chemical_list: D039041:Integrin alpha4beta1; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D016201:Receptors, Lymphocyte Homing; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1