Recurrent herpes simplex virus type 1 (HSV-1) infection is a major cause of viral induced blindness. HSV-1 establishes a life long latent infection with intermittent periods of reactivation. Reactivations can cause recurrent corneal disease leading to blindness. LAT, the only transcriptionally active viral gene during latency, is essential for efficient spontaneous reactivation. Understanding how LAT functions, along with elucidation of other molecular mechanisms behind the HSV-1 latency-reactivation cycle, should lead to the development of a means for reducing the incidence of HSV-1 induced blindness.
The specific aims i nclude: 1. Fine map the region within the first 1.5 kb of LAT that is required for spontaneous reactivation. The PI has recently shown that spontaneous reactivation can be completely rescued in a LAT negative virus by inserting the LAT promoter and the first 1.5 kb of the 8.3 LAT into a novel location in the unique long region. Since this virus can only transcribe LAT from the insert, this mapped LAT's function to within the first 1.5 kb of the primary LAT transcript. He will use this novel system to insert and test smaller and smaller regions of LAT to fine map the minimal region required for efficient spontaneous reactivation. 2. Determine if LAT enhances spontaneous reactivation by enhancing establishment of latency. The amount of latency established by LAT negative mutants versus marker rescued viruses will be estimated by in situ PCR for HSV-1 DNA, in situ hybridization for LAT RNA in mutants that transcribe only nonessential LAT RNA, and in situ hybridization for HSV-1 mRNAs to determine if LAT mutants are defective in terminating acute infection. 3. Determine if there is a LAT protein involved in LAT's function. This will be comparative sequence analysis of the first 1.5 kb of LAT in HSV-1 strains with high spontaneous reactivation rates to find conserved potential open reading frames, followed by site-directed mutagenesis of such potential open reading frames to determine if they are essential for LAT's function.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY007566-10
Application #
2444319
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1988-04-01
Project End
2001-06-30
Budget Start
1997-07-01
Budget End
1998-06-30
Support Year
10
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Cedars-Sinai Medical Center
Department
Type
DUNS #
075307785
City
Los Angeles
State
CA
Country
United States
Zip Code
90048
Perng, Guey-Chuen; Maguen, Barak; Jin, Ling et al. (2002) A novel herpes simplex virus type 1 transcript (AL-RNA) antisense to the 5' end of the latency-associated transcript produces a protein in infected rabbits. J Virol 76:8003-10
Perng, Guey-Chuen; Maguen, Barak; Jin, Ling et al. (2002) A gene capable of blocking apoptosis can substitute for the herpes simplex virus type 1 latency-associated transcript gene and restore wild-type reactivation levels. J Virol 76:1224-35
Perng, Guey-Chuen; Mott, Kevin R; Osorio, Nelson et al. (2002) Herpes simplex virus type 1 mutants containing the KOS strain ICP34.5 gene in place of the McKrae ICP34.5 gene have McKrae-like spontaneous reactivation but non-McKrae-like virulence. J Gen Virol 83:2933-42
Moxley, Michael J; Block, Timothy M; Liu, Hsi-Chou et al. (2002) Herpes simplex virus type 1 infection prevents detachment of nerve growth factor-differentiated PC12 cells in culture. J Gen Virol 83:1591-600
Samoto, Ken; Ehtesham, Moneeb; Perng, Guey-Chuen et al. (2002) A herpes simplex virus type 1 mutant with gamma 34.5 and LAT deletions effectively oncolyses human U87 glioblastomas in nude mice. Neurosurgery 50:599-605; discussion 605-6
Henderson, Gail; Peng, Weiping; Jin, Ling et al. (2002) Regulation of caspase 8- and caspase 9-induced apoptosis by the herpes simplex virus type 1 latency-associated transcript. J Neurovirol 8 Suppl 2:103-11
Inman, M; Perng, G C; Henderson, G et al. (2001) Region of herpes simplex virus type 1 latency-associated transcript sufficient for wild-type spontaneous reactivation promotes cell survival in tissue culture. J Virol 75:3636-46
Perng, G C; Slanina, S M; Ghiasi, H et al. (2001) The effect of latency-associated transcript on the herpes simplex virus type 1 latency-reactivation phenotype is mouse strain-dependent. J Gen Virol 82:1117-22
Perng, G C; Esmaili, D; Slanina, S M et al. (2001) Three herpes simplex virus type 1 latency-associated transcript mutants with distinct and asymmetric effects on virulence in mice compared with rabbits. J Virol 75:9018-28
Perng, G C; Jones, C; Ciacci-Zanella, J et al. (2000) Virus-induced neuronal apoptosis blocked by the herpes simplex virus latency-associated transcript. Science 287:1500-3

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