Retrotransposition and cell-to-cell transfer of foamy viruses.
A remarkable feature of the prototype foamy virus (PFV) replication pathway has been reported to consist of the ability to retrotranspose intracellularly with high efficiency (M. Heinkelein, T. Pietschmann, G. Jármy, M. Dressler, H. Imrich, J. Thurow, D. Lindemann, M. Bock, A. Moebes, J. Roy, O. Herchenröder, and A. Rethwilm, EMBO J. 19:3436-3345, 2000). PFV intracellular retrotransposition (IRT) was reported to be enhanced by coexpression of fusion-defective envelope protein. To investigate the possibility of cell-to-cell transfer of PFV genomes, which could mimic IRT, we performed cocultivation experiments with cells transfected with an IRT-competent and marker gene-expressing PFV vector together with cells expressing a different marker and measured cells positive for both markers. The findings corroborated the initial report on IRT of Env-deficient PFV. Furthermore, they indicated that viral cores that have incorporated fusion-deficient Env can be transferred from cell to cell in a cell type-specific manor. One possible explanation consists of a minor alternative cleavage site in Env that can be used to expose the fusion peptide of the Env transmembrane protein, which appears to be required for virus uptake.
Heinkelein
Martin
M
Institut für Virologie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
Rammling
Matthias
M
Juretzek
Thomas
T
Lindemann
Dirk
D
Rethwilm
Axel
A
D002459:Cell Fusion; D002460:Cell Line; D015686:Gene Products, env / Q000235:genetics*; D005819:Genetic Markers; D005822:Genetic Vectors; D016679:Genome, Viral; D006367:HeLa Cells / Q000821:virology; D006801:Humans; D009154:Mutation; D018626:Retroelements / Q000235:genetics*; D016092:Spumavirus / Q000235:genetics* / Q000502:physiology*; D014162:Transfection
D015686:Gene Products, env; D005819:Genetic Markers; D018626:Retroelements