Journal article
HCMV-infected cells maintain efficient nucleotide excision repair of the viral genome while abrogating repair of the host genome
PLoS pathogens, Vol.8(11), pp.e1003038-e1003038
2012
Handle:
https://hdl.handle.net/2376/108088
PMCID: PMC3510244
PMID: 23209410
Abstract
Many viruses subvert the host cell's ability to mount and complete various DNA damage responses (DDRs) after infection. HCMV infection of permissive fibroblasts activates host DDRs at the time of viral deposition and during replication, but the DDRs remain uncompleted without arrest or apoptosis. We believe this was in part due to partitioning of the damage response and double strand break repair components. After extraction of soluble proteins, the localization of these components fell into three groups: specifically associated with the viral replication centers (RCs), diffused throughout the nucleoplasm and excluded from the RCs. Others have shown that cells are incapable of processing exogenously introduced damage after infection. We hypothesized that the inability of the cells to process damage might be due to the differential association of repair components within the RCs and, in turn, potentially preferential repair of the viral genome and compromised repair of the host genome. To test this hypothesis we used multiple strategies to examine repair of UV-induced DNA damage in mock and virus-infected fibroblasts. Comet assays indicated that repair was initiated, but was not completed in infected cells. Quantitative analysis of immunofluorescent localization of cyclobutane pyrimidine dimers (CPDs) revealed that after 24 h of repair, CPDs were significantly reduced in viral DNA, but not significantly changed in the infected host DNA. To further quantitate CPD repair, we developed a novel dual-color Southern protocol allowing visualization of host and viral DNA simultaneously. Combining this Southern methodology with a CPD-specific T4 endonuclease V alkaline agarose assay to quantitate repair of adducts, we found efficient repair of CPDs from the viral DNA but not host cellular DNA. Our data confirm that NER functions in HCMV-infected cells and almost exclusively repairs the viral genome to the detriment of the host's genome.
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Details
- Title
- HCMV-infected cells maintain efficient nucleotide excision repair of the viral genome while abrogating repair of the host genome
- Creators
- John M O'Dowd - Department of Biological Sciences and Center for Reproductive Biology, University of Idaho, Moscow, Idaho, United States of AmericaAnamaria G ZavalaCeleste J BrownToshio MoriElizabeth A Fortunato
- Publication Details
- PLoS pathogens, Vol.8(11), pp.e1003038-e1003038
- Academic Unit
- UNKNOWN
- Publisher
- United States
- Grant note
- R21 AI051463 / NIAID NIH HHS R01- AI51463 / NIAID NIH HHS R01 AI051463 / NIAID NIH HHS P20 RR015587 / NCRR NIH HHS #P20 RR015587 / NCRR NIH HHS
- Identifiers
- 99900547021901842
- Language
- English
- Resource Type
- Journal article