Infection by herpes simplex virus type 1 (HSV-1) can result in relatively mild cutaneous lesions, and more severe outcomes such as blindness and encephalitis. These diseases are the result of expressed viral gene products during the productive replication cycle of the virus and the host's response to infection. The ~80 viral genes are expressed in an ordered cascade of three general classes;immediate early (IE), early (E) and late (L) genes. Each gene has its own promoter, and the architecture of each class of promoter is distinct. However, details regarding the requirements for expression of the three classes of genes are not entirely understood. ICP4 is a transactivator of polII transcription that is required for the efficient expression of viral early and late genes, and hence viral growth. In eukaryotic cells, different core promoter recognition factors/complexes may be involved in regulating the transcription of cellular genes with different core promoter architectures. We hypothesize that ICP4 interacts with different cellular transcription factors, including different core promoter recognition factors, during different stages of infection to differentially activate early and late genes, thereby contributing to the observed regulatory cascade. Data is presented that the cellular complexes TFIID and med are be two such factors. It also follows that distinct but also overlapping domains of ICP4 are involved in the interactions resulting in the activation of early and late genes. Three interwoven specific aims are proposed to address these hypotheses: (i) Determine and characterize the ICP4-containing complexes seen in HSV infected cells by affinity purification and proteomic approaches, and ascertain how they quantitatively and/or qualitatively change throughout infection. (ii) Virus genetics experiments will be conducted to determine the regions of ICP4 required for the formation of the complexes indicated in aim 1, and the consequence of these regions (and hence the interactions) for viral gene expression during infection. (iii) Chromatin immunoprecipitation (ChIP) experiments will be conducted on infected cells to determine how the complexes discovered in aim 1 associate with the different classes of promoters and affect the assembly of transcription initiation complexes throughout infection. Mutants defective in the interactions discovered in aim 1 (from aim 2) will also be analyzed by ChIP to determine how the interactions affect transcription complex formation on HSV promoters. Outcomes will be interpreted with respect to the gene expression phenotypes of the mutant viruses. All of the proposed genetic and biochemical experiments are conducted in the physiologically relevant context of viral infection and are designed to elucidate molecular details of the regulation of HSV gene transcription and eukaryotic transcription program switching in general. The approaches also account for the changes in the cellular transcriptional machinery that may occur as infection proceeds. Knowledge of these molecular details should eventually translate to strategies to control events in the virus life cycle.
The diseases caused by HSV are the result of expressed viral gene products during the lytic replication cycle of the virus, and the host's response to infection. The focus of this competitive renewal application is to determine the viral and cellular proteins and mechanisms that contribute to the regulated transcription of HSV genes. Detailed knowledge of how HSV genes are transcribed and what interactions contribute to their regulated expression may allow for strategies to block activated transcription and hence virus multiplication.
|Colgrove, Robert C; Liu, Xueqiao; Griffiths, Anthony et al. (2016) History and genomic sequence analysis of the herpes simplex virus 1 KOS and KOS1.1 sub-strains. Virology 487:215-21|
|Dembowski, Jill A; DeLuca, Neal A (2015) Selective recruitment of nuclear factors to productively replicating herpes simplex virus genomes. PLoS Pathog 11:e1004939|
|Thomann, Sabrina; Boscheinen, Jan B; Vogel, Karin et al. (2015) Combined cytotoxic activity of an infectious, but non-replicative herpes simplex virus type 1 and plasmacytoid dendritic cells against tumour cells. Immunology 146:327-38|
|Harkness, Justine M; Kader, Muhamuda; DeLuca, Neal A (2014) Transcription of the herpes simplex virus 1 genome during productive and quiescent infection of neuronal and nonneuronal cells. J Virol 88:6847-61|
|Wagner, Lauren M; Bayer, Avraham; Deluca, Neal A (2013) Requirement of the N-terminal activation domain of herpes simplex virus ICP4 for viral gene expression. J Virol 87:1010-8|
|Wagner, Lauren M; DeLuca, Neal A (2013) Temporal association of herpes simplex virus ICP4 with cellular complexes functioning at multiple steps in PolII transcription. PLoS One 8:e78242|
|Wagner, Lauren M; Lester, Jonathan T; Sivrich, Frances L et al. (2012) The N terminus and C terminus of herpes simplex virus 1 ICP4 cooperate to activate viral gene expression. J Virol 86:6862-74|
|Lester, Jonathan T; DeLuca, Neal A (2011) Herpes simplex virus 1 ICP4 forms complexes with TFIID and mediator in virus-infected cells. J Virol 85:5733-44|
|Sampath, Padmavathi; Deluca, Neal A (2008) Binding of ICP4, TATA-binding protein, and RNA polymerase II to herpes simplex virus type 1 immediate-early, early, and late promoters in virus-infected cells. J Virol 82:2339-49|
|Zabierowski, Susan E; Deluca, Neal A (2008) Stabilized binding of TBP to the TATA box of herpes simplex virus type 1 early (tk) and late (gC) promoters by TFIIA and ICP4. J Virol 82:3546-54|
Showing the most recent 10 out of 30 publications