Purchase this article with an account.
P.R. Kinchington, S.A. Harvey; Microarray Analysis of Varicella Zoster Virus (VZV)-Infected Cells Identifies Novel Host Cell Targets of a Viral Protein Kinase . Invest. Ophthalmol. Vis. Sci. 2003;44(13):4184.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Herpes zoster causes blinding diseases which affect the elderly. We are studying viral encoded protein kinases as targets for antivirals or even as antiviral proteins themselves. The serine/threonine-specific protein kinase from VZV gene 66 appears to phosphorylate both viral and cellular targets and may affect host cell signalling pathways. To determine the cellular targets of gene 66 kinase, we used microarray analysis to compare the effects of wild-type VZV (Roka) on host cell expression with those of Roka66S, which is deleted for gene 66. Methods: Three independent preparations of human melanoma cells (MeWo) were either mock infected, or infected with Roka or Roka66S. At 48h post-infection total RNA was harvested, reverse-transcribed, labeled, and analyzed using Affymetrix HU95Av2 chips. Results: Two independent analyses of one sample gave r2 = 0.987, indicating very high reproducibility. The number of detected transcripts was similar between controls (5773 ± 666, mean ± SD, n=4) and virus infected samples (5317 ± 627, mean ± SD, n=6). We calculated the unnormalized mean signal for each sample, using only the transcripts consistently present in all samples. The group mean for virus-infected samples (480 ± 67, mean ± SD, n=5) was significantly less than for controls (809 ± 100, mean ± SD, n=4), consistent with down-regulation of host mRNAs by viral infection. Against this background of global down-regulation, expression of forty host genes were up-regulated over 2 fold by Roka infection, including three members of the heat-shock protein 70 kD (Hsp70) family, and 12 members of the histone H2 family. Compared with Roka, infection with Roka66S up-regulated histones to the same degree but was less effective (mean fold ≤ 0.5) at increasing Hsp70 family expression, suggesting that gene 66 kinase is not required for histone up-regulation but does participate in Hsp70 up-regulation. Five additional Roka-augmented transcripts showed plausible association with gene 66 kinase function, including transcription factor Rel, and the host protein phosphatase regulatory unit, PPP4R2. The target of PPP4R2 is PPP4C, which associates with Rel and enhances its DNA binding activity. PPP4C is robustly expressed and unchanged by viral infection, so gene 66 kinase may modulate host transcription via changes in Rel and PPP4R2. Conclusions: We have identified specific changes in host expression associated with a single viral component. Using other gene-deleted VZV, further microarray analyses will provide a detailed map of additional key host-virus interactions.
This PDF is available to Subscribers Only