Establishment of a GFP-based indicator cell line to quantitate feline foamy virus

Hang T.T. Phung, Yukinobu Tohya, Masayuki Shimojima, Kentaro Kato, Takayuki Miyazawa, Hiroomi Akashi

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


To quantitate infectious feline foamy virus (FeFV), Crandell feline kidney (CRFK) cells were transfected with the gfp gene under the control of the FeFV long terminal repeat (LTR) for establishing an indicator cell line named FFG cells. The FeFV activates promoter activity of the LTR to express green fluorescent protein (GFP) upon infection. The titers determined by GFP-positive FFG cells (GFP-based assay) were higher than those determined by the cytopathic effects-positive CRFK cells (CPE-based assay). The titers determined by the GFP-based assay reached a plateau at 3-4 days post infection (d.p.i.), while those by the CPE-based assay reached 6-8 d.p.i. When stock viruses of various FeFV strains were titrated by both assays, titers determined by both assays correlated well with each other. The results show that the GFP-based assay is simpler and more rapid and sensitive than the CPE-based assay. Using the GFP-based assay, we examined the in vitro host range of FeFV. It was found that FeFV can productively infect various cell lines derived from cats, dogs, chickens, a human and a bat.

Original languageEnglish
Pages (from-to)125-131
Number of pages7
JournalJournal of Virological Methods
Issue number2
Publication statusPublished - 2003 May


  • Cell-tropism
  • Feline foamy virus
  • GFP
  • Titration
  • Transactivation


Dive into the research topics of 'Establishment of a GFP-based indicator cell line to quantitate feline foamy virus'. Together they form a unique fingerprint.

Cite this