title: [Intercellular transmission of HTLV-1: not all mechanisms have been revealed].
abstract: HTLV-1 is the etiological agent of Adult T cell Leukemia/Lymphoma (ATLL) and of HTLV-1-Associated Myelopathy/tropical spastic paraparesis (HAM/TSP). It is mainly detected in CD4+ lymphocytes in vivo, but proviral genomes have also been detected although less frequently, in CD8+ T lymphocytes, B lymphocytes, monocytes, macrophages, dendritic cells and other non-lymphoid cells. Virus spread is highly dependent on cell-cell contact. This mode of transmission is correlated with an increased ability of infected cells to migrate, a property linked to cytoskeleton reorganization induced by the viral Tax protein. Cell-to-cell transmission relies on at least three non-exclusive molecular pathways. First, a specialized area, the "virological synapse'' (VS) promotes direct transmission of budding HTLV-1 particles into a synaptic cleft formed between infected and uninfected cells. Second, HTLV-1 particles accumulate at the plasma membrane of infected cells in a biofilm-like extracellular viral assembly that resembles a bacterial biofilm. Viral biofilm is rapidly transmitted to uninfected cells when infected cells contact target cells. Finally, membrane extensions called inter-cellular conduits facilitate HTLV-1 proteins transfer from infected to uninfected target cells, and may stabilize cell-cell contacts. The aim of this review is to summarize the molecular mechanisms of these HTLV-1 transmission pathways.
authors.affiliation: Équipe oncogenèse rétrovirale ; équipe labellisée Ligue nationale contre le cancer ; centre international de recherche en infectiologie, Inserm U1111-CNRS UMR5308, Lyon, France - École normale supérieure de Lyon, 46, allée d'Italie, 69007 Lyon, France - Université Lyon 1, Lyon Cedex 07, 69364, France.
authors.forename: Gerges
authors.initials: G
authors.lastname: Rizkallah
authors.affiliation: Équipe oncogenèse rétrovirale ; équipe labellisée Ligue nationale contre le cancer ; centre international de recherche en infectiologie, Inserm U1111-CNRS UMR5308, Lyon, France - École normale supérieure de Lyon, 46, allée d'Italie, 69007 Lyon, France - Université Lyon 1, Lyon Cedex 07, 69364, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Mahieux
authors.affiliation: Équipe oncogenèse rétrovirale ; équipe labellisée Ligue nationale contre le cancer ; centre international de recherche en infectiologie, Inserm U1111-CNRS UMR5308, Lyon, France - École normale supérieure de Lyon, 46, allée d'Italie, 69007 Lyon, France - Université Lyon 1, Lyon Cedex 07, 69364, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Dutartre
mesh_terms: D000328:Adult; D000818:Animals; D018441:Biofilms / Q000254:growth & development; D002450:Cell Communication; D002465:Cell Movement; D016764:Cell Polarity; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D006801:Humans; D056189:Viral Tropism / Q000502:physiology; D053586:Virus Internalization