Interferons (IFN) are proteins produced by cells in response to virus infection. There are three major IFN types, alpha, beta, and gamma. IFNs are not directly antiviral, but induce their antiviral actions by binding to cell receptors and inducing the production of a group of 20 or more proteins, some of which have been shown to be responsible for antiviral activity. IFNs play important roles in the response to herpes simplex virus (HSV) infections, including ocular infections causing herpetic keratitis and acute retinal necrosis. IFN-alpha combined with acyclovoir, an inhibitor of HSV DNA synthesis, produced synergistic anti-HSV activity in cornea stromal cells. In these cells IFN-alpha was found to reduce the level of several members of the early temporal class of proteins. These affected proteins are enzymes responsible for nucleoside metabolism and for viral DNA replication. Although early proteins levels are decreased, the mRNA levels which encode these enzymes were increased. Three mechanisms for this regulation will be investigated; (i) a decrease in mRNA association with polysomes, (ii) a decrease rate of translation, or (iii) an increase in the degradation of protein. The function of four IFN- inducible proteins with known antiviral action against other viruses will be studied: (i) The activity of the double-stranded RNA-activated protein kinase that phosphorylates a factor required for initiation of translation will be measured; (ii) The binding of IFN-induced RNA-binding proteins, for example 9-27, will be detected by gel shift assay; (iii) The binding of HSV early protein to the p15 protein, a protein with sequence homology to ubiquitin, the protein that binds to and targets proteins for degradation will be examined by immunoprecipitation and immunoblot; and (iv) The Mx protein that appears to function in protein transport within the cells will be assessed by immunofluorescence for co-localization with HSV proteins. The three major types of IFNs will be tested to determine whether their combined function in cornea stromal cells is synergistic with each other and with acyclovir in the inhibition of HSV replication and whether they also inhibit early protein synthesis or function by different mechanisms. Finally, we will examine the effects of IFN's on HSV replication in retinal pigment epithelial cells, a target cell for the virus infection in acute retinal necrosis. The mechanism of action of IFNs in these retinal cells will be assessed to determine whether IFNs effects are the same as in cornea stromal cells. These studies will allow us to understand how endogenously produced IFNs function to restrict HSV replication during ocular infection and how they may be used exogenously alone or with conventional antiviral agents to treat HSV ocular infections.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY006990-11
Application #
2414996
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1987-05-01
Project End
1999-04-30
Budget Start
1997-05-01
Budget End
1998-04-30
Support Year
11
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Medical College of Wisconsin
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
073134603
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Taylor, J L; Unverrich, D; O'Brien, W J et al. (2000) Interferon coordinately inhibits the disruption of PML-positive ND10 and immediate-early gene expression by herpes simplex virus. J Interferon Cytokine Res 20:805-15
O'Brien, W J; Narasimhan, J; Guy, J et al. (1998) The effects of interferon-alpha and acyclovir on herpes simplex virus type-1 ribonucleotide reductase. Antiviral Res 38:107-16
Taylor, J L; Grossberg, S E (1998) The effects of interferon-alpha on the production and action of other cytokines. Semin Oncol 25:23-9
Taylor, J L; Witt, P L; Irizarry, A et al. (1995) 2',5'-oligoadenylate synthetase in interferon-alpha- and acyclovir-treated herpes simplex virus-infected cells. J Interferon Cytokine Res 15:27-30
Taylor, J L; Tom, P; Guy, J et al. (1994) Regulation of herpes simplex virus thymidine kinase in cells treated with a synergistic antiviral combination of alpha interferon and acyclovir. Antimicrob Agents Chemother 38:853-6
Taylor, J L; Punda-Polic, V; O'Brien, W J (1991) Combined anti-herpes virus activity of nucleoside analogs and interferon. Curr Eye Res 10 Suppl:205-11
Hendricks, R L; Weber, P C; Taylor, J L et al. (1991) Endogenously produced interferon alpha protects mice from herpes simplex virus type 1 corneal disease. J Gen Virol 72 ( Pt 7):1601-10
O'Brien, W J; Coe, E C; Taylor, J L (1990) Nucleoside metabolism in herpes simplex virus-infected cells following treatment with interferon and acyclovir, a possible mechanism of synergistic antiviral activity. Antimicrob Agents Chemother 34:1178-82
Taylor, J L; Grossberg, S E (1990) Recent progress in interferon research: molecular mechanisms of regulation, action, and virus circumvention. Virus Res 15:1-25
Taylor, J L; Casey, M S; O'Brien, W J (1989) Synergistic antiherpes virus activity of acyclovir and interferon in human corneal stromal cells. Invest Ophthalmol Vis Sci 30:365-70

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