The influence of DNA methylation in vitro on the activity of the very strong human cytomegalovirus (HCMV) major immediate early (IE) modulator/enhancer/promoter region was investigated by transient transfection experiments of premonocytic HL-60 cells. While sequence-specific methylation of the major IE enhancer and/or modulator with the cytosine methyl-transferases FnuDII, HhaI and HaeIII had no significant effect, the promoter activity was completely repressed by methylation of the cytosine in 5'-CpG sites with the Spiroplasma methyltransferase SssI. Addition of TNF-alpha or PMA which are strong stimulators of HCMV major IE enhancer/promoter activity in premonocytic HL-60 cells had no effect on repression. Inactivation of the IE enhancer/promoter via methylation by M.SssI could be partially alleviated by co-transfection with an excess of untranscribable highly methylated DNA. These results indicate that a methyl-CpG binding factor is involved as mediator in the inhibitory effect of HCMV enhancer/promoter methylation. Taken together, the HCMV major IE enhancer/ promoter has been shown to be susceptible to transcriptional inactivation by methylation of the cytosines in CpG dinucleotides, a process that is proposed to play a modulatory role in viral latency.
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http://dx.doi.org/10.1515/bchm3.1996.377.3.195 | DOI Listing |
J Clin Invest
January 2025
Department of Pediatrics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
The pursuit of a vaccine against the human cytomegalovirus (HCMV) has been ongoing for more than 50 years. HCMV is the leading infectious cause of birth defects, including damage to the brain, and is a common cause of complications in organ transplantation. The complex biology of HCMV has made vaccine development difficult, but a recent meeting sponsored by the National Institute of Allergy and Infectious Diseases in September of 2023 brought together experts from academia, industry, and federal agencies to discuss progress in the field.
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Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA.
The human cytomegalovirus (HCMV) encoded chemokine receptor US28 plays a critical role in viral pathogenesis, mediating several processes such as cellular migration, differentiation, transformation, and viral latency and reactivation. Despite significant research examining the signal transduction pathways utilized by US28, the precise mechanism by which US28 activates these pathways remains unclear. We performed a mutational analysis of US28 to identify signaling domains that are critical for functional activities.
View Article and Find Full Text PDFJ Virol
November 2024
Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world's population. Lytic HCMV replication in immunocompromised individuals or neonates can lead to severe disease in multiple organ systems and even death. The establishment of lytic replication is driven by the first viral proteins expressed upon infection, the immediate early proteins, which play a key role in creating an intracellular environment conducive to virus replication.
View Article and Find Full Text PDFbioRxiv
October 2024
Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA.
Human cytomegalovirus (HCMV) causes severe birth defects, lifelong health complications, and $4 billion in annual costs in the United States alone. A major challenge in vaccine design is the incomplete understanding of the diverse protein complexes the virus uses to infect cells. In , the gH/gL glycoprotein heterodimer is expected to be a basal element of virion cell entry machinery.
View Article and Find Full Text PDFSci Immunol
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Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA.
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