title: Insertion of myeloid-active elements into the human cytomegalovirus major immediate early promoter is not sufficient to drive its activation upon infection of undifferentiated myeloid cells.
abstract: The Major Immediate Early Promoter (MIEP) of human cytomegalovirus (HCMV) controls viral Immediate Early (IE) gene expression, which must be activated to initiate productive infection and repressed to establish latency. Regulation of the MIEP is critical for both viral spread and persistence. In addition to the Daxx-mediated intrinsic cellular defense that regulates the MIEP, the cell-type specific balance between cellular activators and repressors of the promoter may help dictate whether viral IE genes will be expressed or silenced. For example, in undifferentiated myeloid cells, transcriptional repressors of the MIEP may outnumber transcriptional activators, leading to promoter silencing and latency establishment. We created a recombinant viral genome in which a myeloid-active promoter replaced part of the MIEP. The viable virus generated failed to express the viral IE genes in an undifferentiated myeloid cell line. These observations have mechanistic implications regarding how viral IE gene expression is regulated during latency.
authors: Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors: Qingsong
authors: Q
authors: Qin
authors: Song Hee
authors: SH
authors: Lee
authors: Ruibin
authors: R
authors: Liang
authors: Robert F
authors: RF
authors: Kalejta
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D003587:Cytomegalovirus / Q000235:genetics* / Q000502:physiology; D003586:Cytomegalovirus Infections / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D017781:Genes, Immediate-Early; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D016254:Mutagenesis, Insertional; D022423:Myeloid Cells / Q000166:cytology / Q000821:virology*; D011401:Promoter Regions, Genetic; D014775:Virus Activation; D017735:Virus Latency
chemical_list: D017874:Immediate-Early Proteins
keywords: Human cytomegalovirus; Major immediate early promoter; Myeloid-active promoter; Undifferentiated myeloid cells