title: Mobilization of full-length Semliki Forest virus replicon by retrovirus particles.
abstract: Conciliating biosafety with efficient gene transfer remains a constant concern in the development of retroviral vectors. Semliki Forest virus (SFV) replicons allow important retroviral vector production with interesting features. It is noteworthy that retroviruses have the ability to package Psi+ and, to some extent, Psi- cellular RNAs. Therefore, it was important to study the retroviral transfer of highly abundant SFV genomes expressing retroviral proteins. Here, we show that full-length SFV-vector replicons, with or without Psi, are efficiently packaged into retrovirus particles. Mechanistically, our data suggest that SFV packaging is the sum of its retroviral nucleocapsid-dependent recruitment together with a passive hijacking of membrane-anchored SFV replicon. A direct consequence of this phenomenon is the formation of particles harboring autonomous replicative abilities and contaminating vector preparations. Importantly, we confirm that retroviral SFV mobilization is not an exclusive feature of murine gamma retroviruses, since it is also observed using lentivectors.
authors.affiliation: Université François Rabelais, INSERM ERI 19, EA 3856-IFR 136, Faculté de Médecine de Tours, 10 Bd Tonnellé, Tours, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Piver
authors.forename: Christine
authors.initials: C
authors.lastname: Collin
authors.forename: Noémie
authors.initials: N
authors.lastname: Renault
authors.forename: Thierry
authors.initials: T
authors.lastname: Bru
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Pagès
mesh_terms: D005822:Genetic Vectors / Q000235:genetics; D012093:Replicon / Q000235:genetics*; D012190:Retroviridae / Q000502:physiology*; D012672:Semliki forest virus / Q000235:genetics*; D014771:Virion / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*