Absence of PKR attenuates the anti-HSV-1 activity of an adenoviral vector expressing murine IFN-beta.

Abstract

A study was undertaken to evaluate the efficacy of an adenoviral vector containing the murine interferon-beta (IFN-beta) transgene (Ad:IFN-beta) against herpes simplex virus type 1 (HSV-1) infection in two transduced cell lines. The transduction of the adenoviral vector efficiency, ranging from 2% to 100%, was dependent on the multiplicity of infection (moi) (0.4-50 plaque-forming units [pfu]/cell). Supernatants from cells transduced with the Ad:IFN-beta but not the adenoviral null vector (Ad:Null) contained biologically active IFN-beta (6.6-106 U/ml depending on the moi). Cells transduced with the Ad:IFN-beta displayed up to 25-fold reduction in viral titers compared with cells transduced with the Ad:Null or nontransduced cell controls. The suppression in viral titer correlated with a reduction in viral gene (alpha, beta, and gamma) and protein expression. The expression of IFN beta-responsive genes, including protein kinase R (PKR) and 2',5'-oligoadenylate synthetase (OAS), were significantly elevated in the Ad:IFN-beta-transduced cells by 12-fold and 25-fold, respectively. However, after infection with HSV-1, a transient but significant drop in PKR but not OAS gene expression was observed 10 h postinfection. The absence of PKR but not RNase L significantly attenuated the antiviral efficacy of the transgene. Collectively, these results illustrate the feasibility of employing a viral vector to deliver a potent antiviral gene to targeted cells without any obvious detriment to the vector itself and support an important role for PKR as a mediator of the anti-HSV-1 activity of type I IFN.

• Authors: Khaldun Al-Khatib, Bryan R G Williams, Robert H Silverman, William P Halford, Daniel J J Carr
• Journal: Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research (J Interferon Cytokine Res) Vol. 22 Issue 8 Pg. 861-71 (Aug 2002) ISSN: 1079-9907 [Print] United States
• PMID: 12396725 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Recombinant Fusion Proteins
• Viral Proteins
• Interferon-beta
• eIF-2 Kinase
• 2',5'-Oligoadenylate Synthetase
• Endoribonucleases
• 2-5A-dependent ribonuclease

Topics

• 2',5'-Oligoadenylate Synthetase (biosynthesis, genetics)
• Adenoviridae (genetics)
• Animals
• Cell Line (virology)
• Chlorocebus aethiops
• Endoribonucleases (deficiency, physiology)
• Enzyme Induction
• Feasibility Studies
• Fibroblasts (virology)
• Gene Expression Regulation, Viral
• Genetic Therapy
• Genetic Vectors (genetics, pharmacology)
• Interferon-beta (biosynthesis, genetics, physiology)
• L Cells (virology)
• Mice
• Recombinant Fusion Proteins (biosynthesis, physiology)
• Simplexvirus (physiology)
• Transduction, Genetic
• Vero Cells
• Viral Proteins (biosynthesis, genetics)
• eIF-2 Kinase (biosynthesis, deficiency, genetics, physiology)