Gene Transfer into Mammalian Cells Using a Self-Deleting Avian Leukemia and Sarcoma Virus-Based Vector

Objectives: We have previously described an avian leukemia and sarcoma virus-based vector containing an additional att sequence in an internal position that is capable of self-deleting most of its 5' viral sequences during one cycle of replication in avian cells [Virus Res 2008; 135: 72-82; Arch Virol 2008; 153: 2233-2243]. Herein, our aim was to test the infectivity and self-deleting properties of this avian retroviral vector in human cells. Methods: Human Hela cells transiently expressing the cellular receptor for avian leukemia and sarcoma viruses (tva) were infected with the avian vector. Molecular analyses of thirteen clones were performed. Results: Data showed that more than 77% of proviruses had lost the 5' part of their genome including the selectable gene. At least 61% of these proviruses were flanked on the left by the additional att sequence and on the right by the LTR. None of the thirteen proviruses was able to express a full-length genomic RNA. Conclusion: This study demonstrates that the self-deleting properties of the avian vector in avian cells may be also applicable to human cells. Copyright (C) 2009 S. Karger AG, Basel