Herpes simplex virus 1 (HSV-1) latency establishment is tightly controlled by promyelocytic leukemia (PML) nuclear bodies (NBs) (or ND10), although their exact contribution is still elusive. A hallmark of HSV-1 latency is the interaction between latent viral genomes and PML NBs, leading to the formation of viral DNA-containing PML NBs (vDCP NBs), and the complete silencing of HSV-1. Using a replication-defective HSV-1-infected human primary fibroblast model reproducing the formation of vDCP NBs, combined with an immuno-FISH approach developed to detect latent/quiescent HSV-1, we show that vDCP NBs contain both histone H3.3 and its chaperone complexes, i.e., DAXX/ATRX and HIRA complex (HIRA, UBN1, CABIN1, and ASF1a). HIRA also co-localizes with vDCP NBs present in trigeminal ganglia (TG) neurons from HSV-1-infected wild type mice. ChIP and Re-ChIP show that vDCP NBs-associated latent/quiescent viral genomes are chromatinized almost exclusively with H3.3 modified on its lysine (K) 9 by trimethylation, consistent with an interaction of the H3.3 chaperones with multiple viral loci and with the transcriptional silencing of HSV-1. Only simultaneous inactivation of both H3.3 chaperone complexes has a significant impact on the deposition of H3.3 on viral genomes, suggesting a compensation mechanism. In contrast, the sole depletion of PML significantly impacts the chromatinization of the latent/quiescent viral genomes with H3.3 without any overall replacement with H3.1. vDCP NBs-associated HSV-1 genomes are not definitively silenced since the destabilization of vDCP NBs by ICP0, which is essential for HSV-1 reactivation in vivo, allows the recovery of a transcriptional lytic program and the replication of viral genomes. Consequently, the present study demonstrates a specific chromatin regulation of vDCP NBs-associated latent/quiescent HSV-1 through an H3.3-dependent HSV-1 chromatinization involving the two H3.3 chaperones DAXX/ATRX and HIRA complexes. Additionally, the study reveals that PML NBs are major actors in latent/quiescent HSV-1 H3.3 chromatinization through a PML NB/histone H3.3/H3.3 chaperone axis.
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http://dx.doi.org/10.1371/journal.ppat.1007313 | DOI Listing |
Sci Rep
January 2025
Bioinformatics Centre, Savitribai Phule Pune University, Pune, Maharashtra, 411007, India.
COVID-19 has proved to be a global health crisis during the pandemic, and the emerging JN.1 variant is a potential threat. Therefore, finding alternative antivirals is of utmost priority.
View Article and Find Full Text PDFNat Commun
January 2025
Molecular and Cellular Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC, 27709, USA.
Coronaviruses evade detection by the host immune system with the help of the endoribonuclease Nsp15, which regulates levels of viral double stranded RNA by cleaving 3' of uridine (U). While prior structural data shows that to cleave double stranded RNA, Nsp15's target U must be flipped out of the helix, it is not yet understood whether Nsp15 initiates flipping or captures spontaneously flipped bases. We address this gap by designing fluorinated double stranded RNA substrates that allow us to directly relate a U's sequence context to both its tendency to spontaneously flip and its susceptibility to cleavage by Nsp15.
View Article and Find Full Text PDFOphthalmol Glaucoma
January 2025
Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China. Electronic address:
Purpose: Liver disease is associated with a range of extrahepatic complications, which have recently been expanded to include ophthalmic conditions. However, evidence is lacking regarding its impact on primary open-angle glaucoma (POAG). This study aimed to investigate whether major liver diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD), alcoholic liver disease (ALD), viral hepatitis, and liver fibrosis and cirrhosis, were associated with POAG.
View Article and Find Full Text PDFVet Microbiol
December 2024
Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510462, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Since its emergence, porcine reproductive and respiratory syndrome (PRRS) has caused enormous economic losses to the global swine industry. The pathogenesis of PRRS remains under investigation. The porcine reproductive and respiratory syndrome virus (PRRSV) causes reproductive disorders in pigs and respiratory in piglets, which is a 15 kb RNA virus that encodes 16 viral proteins, most of which exhibit multiple functions during the virus lifecycle.
View Article and Find Full Text PDFBiomaterials
December 2024
Institute of Molecular Virology, Ulm University Medical Center, Ulm, 89081, Germany. Electronic address:
Retroviral gene transfer is the preferred method for stable, long-term integration of genetic material into cellular genomes, commonly used to generate chimeric antigen receptor (CAR)-T cells designed to target tumor antigens. However, the efficiency of retroviral gene transfer is often limited by low transduction rates due to low vector titers and electrostatic repulsion between viral particles and cellular membranes. To overcome these limitations, peptide nanofibrils (PNFs) can be applied as transduction enhancers.
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