title: Fluorescein and radiolabeled Function-Spacer-Lipid constructs allow for simple in vitro and in vivo bioimaging of enveloped virions.
abstract: Tools that can aid in vitro and in vivo imaging and also noninvasively determine half-life and biodistribution are required to advance clinical developments. A Function-Spacer-Lipid construct (FSL) incorporating fluorescein (FSL-FLRO4) was used to label vesicular stomatitis virus (VSV), measles virus MV-NIS (MV) and influenza virus (H1N1). The ability of FSL constructs to label these virions was established directly by FACScan of FSL-FLRO4 labeled VSV and MV, and indirectly following labeled H1N1 and MV binding to a cells. FSL-FLRO4 labeling of H1N1 was shown to maintain higher infectivity of the virus when compared with direct fluorescein virus labeling. A novel tyrosine (125)I radioiodinated FSL construct was synthesized (FSL-(125)I) from FSL-tyrosine. This was used to label VSV (VSV-FSL-(125)I), which was infused into the peritoneal cavity of laboratory mice. Bioscanning showed VSV-FSL-(125)I to localize in the liver, spleen and bloodstream in contrast to the free labels FSL-(125)I or (125)I, which localized predominantly in the liver and thyroid respectively. This is a proof-of-principle novel and rapid method for modifying virions and demonstrates the potential of FSL constructs to improve in vivo imaging of virions and noninvasively observe in vivo biodistribution.
authors.affiliation: Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Hadac
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Federspiel
authors.forename: Evgeny
authors.initials: E
authors.lastname: Chernyy
authors.forename: Alexander
authors.initials: A
authors.lastname: Tuzikov
authors.forename: Elena
authors.initials: E
authors.lastname: Korchagina
authors.forename: Nicolai V
authors.initials: NV
authors.lastname: Bovin
authors.forename: Stephen
authors.initials: S
authors.lastname: Russell
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Henry
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000737:chemistry; D002460:Cell Line; D002522:Chlorocebus aethiops; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D019793:Fluorescein / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry / Q000472:pathogenicity; D007457:Iodine Radioisotopes / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D008459:Measles virus / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D013194:Staining and Labeling / Q000379:methods*; D014018:Tissue Distribution; D014709:Vero Cells; D014721:Vesicular stomatitis Indiana virus / Q000737:chemistry / Q000472:pathogenicity; D014771:Virion / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D007457:Iodine Radioisotopes; D008055:Lipids; D019793:Fluorescein