Inhibition of vesicular stomatitis virus infection in epithelial cells by alpha interferon-induced soluble secreted proteins.
Interferons (IFNs) are potent antiviral cytokines that inhibit infection by a wide spectrum of viruses by activating the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. Several IFN-induced antiviral proteins including 2',5'-oligoadenylate synthetase, dsRNA-activated protein kinase and Mx play a critical role in conferring the antiviral properties of IFN. However, studies have shown that additional antiviral factors are involved in addition to these proteins during IFN-mediated antiviral action. In an effort to characterize these novel antiviral factors, the antiviral mechanism of alpha IFN (IFN-alpha) against vesicular stomatitis virus (VSV) was investigated in human lung epithelial A549 cells. These studies demonstrated that soluble secreted antiviral proteins as the constituents of conditioned medium prepared from IFN-alpha-treated cells reduced VSV infectivity by more than 2 logs, compared with a 4 log inhibition observed following treatment of cells with IFN-alpha. The antiviral mechanism of these secreted proteins appeared to act at the level of cellular entry of VSV. Interestingly, the IFN-alpha-induced antiviral proteins were secreted independently of STAT1 (an essential component of the JAK/STAT pathway), demonstrating that the release of such extracellular soluble antiviral proteins from cells may represent an alternative mechanism of the antiviral defence strategy of IFN towards VSV infection.
Basu
Mausumi
M
Department of Molecular Genetics/Virology Section, The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Maitra
Ratan K
RK
Virus Core Facility, The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Xiang
Yan
Y
Department of Microbiology and Immunology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MC 7758, San Antonio, TX 78229-3900, USA.
Meng
Xiangzhi
X
Department of Microbiology and Immunology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MC 7758, San Antonio, TX 78229-3900, USA.
Banerjee
Amiya K
AK
Department of Molecular Genetics/Virology Section, The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Bose
Santanu
S
Department of Microbiology and Immunology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MC 7758, San Antonio, TX 78229-3900, USA.
D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism; D002460:Cell Line; D017077:Culture Media, Conditioned; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism / Q000821:virology; D006801:Humans; D016898:Interferon-alpha / Q000037:antagonists & inhibitors / Q000502:physiology*; D014176:Protein Biosynthesis; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D050794:STAT1 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D012995:Solubility; D014721:Vesicular stomatitis Indiana virus / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity
D000998:Antiviral Agents; D017077:Culture Media, Conditioned; D016898:Interferon-alpha; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human