Human cytomegalovirus (HCMV) induces human endogenous retrovirus (HERV) transcription.
BACKGROUND
Emerging evidence suggests that human cytomegalovirus (HCMV) is highly prevalent in tumours of different origin. This virus is implied to have oncogenic and oncomodulatory functions, through its ability to control host gene expression. Human endogenous retroviruses (HERV) are also frequently active in tumours of different origin, and are supposed to contribute as cofactors to cancer development. Due to the high prevalence of HCMV in several different tumours, and its ability to control host cell gene expression, we sought to define whether HCMV may affect HERV transcription.


RESULTS
Infection of 3 established cancer cell lines, 2 primary glioblastoma cells, endothelial cells from 3 donors and monocytes from 4 donors with HCMV (strains VR 1814 or TB40/F) induced reverse transcriptase (RT) activity in all cells tested, but the response varied between donors. Both, gammaretrovirus-related class I elements HERV-T, HERV-W, HERV-F and ERV-9, and betaretrovirus-related class II elements HML-2 - 4 and HML-7 - 8, as well as spuma-virus related class III elements of the HERV-L group were up-regulated in response to HCMV infection in GliNS1 cells. Up-regulation of HERV activity was more pronounced in cells harbouring active HCMV infection, but was also induced by UV-inactivated virus. The effect was only slightly affected by ganciclovir treatment and was not controlled by the IE72 or IE86 HCMV genes.


CONCLUSIONS
Within this brief report we show that HCMV infection induces HERV transcriptional activity in different cell types.
Alice
A
Assinger
Koon-Chu
KC
Yaiw
Ingmar
I
Göttesdorfer
Christine
C
Leib-Mösch
Center for Molecular Medicine, Department of Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden. cecilia.naucler@ki.se.
Cecilia
C
Söderberg-Nauclér
D030121:Betaretrovirus / Q000201:enzymology / Q000235:genetics*; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000254:growth & development*; D017988:Gammaretrovirus / Q000201:enzymology / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D006801:Humans; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014158:Transcription, Genetic; D015854:Up-Regulation
D012194:RNA-Directed DNA Polymerase