The interferon-inducible antiviral protein Daxx is not essential for interferon-mediated protection against avian sarcoma virus
Immune Cell Development and Host Defense Program, Fox Chase Cancer Center, Room 422 Reimann Building, 333 Cottman Ave., 19111 Philadelphia, PA, USA
Virology Journal 2014, 11:100 doi:10.1186/1743-422X-11-100Published: 28 May 2014
The antiviral protein Daxx acts as a restriction factor of avian sarcoma virus (ASV; Retroviridae) in mammalian cells by promoting epigenetic silencing of integrated proviral DNA. Although Daxx is encoded by a type I (α/β) interferon-stimulated gene, the requirement for Daxx in the interferon anti-retroviral response has not been elucidated. In this report, we describe the results of experiments designed to investigate the role of Daxx in the type I interferon-induced anti-ASV response.
Using an ASV reporter system, we show that type I interferons are potent inhibitors of ASV replication. We demonstrate that, while Daxx is necessary to silence ASV gene expression in the absence of interferons, type I interferons are fully-capable of inducing an antiviral state in the absence of Daxx.
These results provide evidence that Daxx is not essential for the anti-ASV interferon response in mammalian cells, and that interferons deploy multiple, redundant antiviral mechanisms to protect cells from ASV.