Biology subjects

Verjans, G. M. G. M.

Publications and source records attributed to Verjans, G. M. G. M..

5 recordsLinked to original sources

bioRxiv2025

A human sensory neuron model for varicella-zoster virus latency and reactivation in vitro.

Varicella-zoster virus (VZV) is a ubiquitous human neurotropic alphaherpesvirus that establishes lifelong latency in sensory ganglionic neurons. Subsequent viral reactivation causes herpes zoster, a morbid disease often complicated by neuropathic pain. Mechanisms underlying VZV latency and reactivation are not understood, mostly due to the lack of permissive animal models and challenges of current in vitro latency modelling. Here, we evaluated HD10.6 cells, a simplified and easily expandable human sensory neuron line to model VZV latency and reactivation. Mature HD10.6 (mHD10.6) differentiated neurons supported productive VZV infection, viral DNA replication, production of infectious progeny, and viral spread in cultures. VZV infection was associated with limited cytopathic effects and ultrastructural changes. Infecting mHD10.6 neurons with cell-free VZV in the presence of antivirals resulted in a quiescent-persistent state, characterized by persistent VZV genomes with restricted VZV gene expression and absence of infectious virus. Importantly, VZV could be reactivated by treatment with capsaicin, as evidenced by increased lytic viral transcription and virus spread. In conclusion, this study establishes human HD10.6 neurons as a novel and scalable in vitro model for studying VZV latency and reactivation to identify virus and host factors governing latency that may serve as therapeutic targets to restrict VZV reactivation. ImportanceMost individuals carry latent varicella-zoster virus (VZV) in their dorsal root ganglia (DRG), which can reactivate to cause shingles and chronic pain. The mechanisms by which VZV establishes latency and triggers of reactivation are incompletely understood. Current platforms for the study of VZV latency do not easily support functional experiments (ganglia) or are difficult to expand and complicated by mixed neuronal populations (stem cell-derived neurons). Here, we demonstrate that matured HD10.6 (mHD10.6) cells derived from immortalized human DRG-derived neurons provide a clonal, scalable, and easy-to-expand platform for studying lytic, latent, and reactivated VZV infection in sensory neurons. We propose that the HD10.6 platform could provide the basis to conduct studies on the viral latent state that have hitherto not been possible.

microbiology↗

bioRxiv2023

Reanalysis of single-cell RNA sequencing data does not support herpes simplex virus 1 latency in non-neuronal ganglionic cells in mice

Most individuals are latently infected with herpes simplex virus type 1 (HSV-1) and it is well-established that HSV-1 establishes latency in sensory neurons of peripheral ganglia. However, it was recently proposed that latent virus is also present in immune cells recovered from ganglia in a mouse model used for studying latency. Here, we reanalyzed the single-cell RNA sequencing (scRNA-Seq) data that formed the basis for this conclusion. Unexpectedly, off-target priming in 3 scRNA-Seq experiments enabled the detection of non-polyadenylated HSV-1 latency-associated transcript (LAT) intronic RNAs. However, LAT reads were near-exclusively detected in a mixed population of cells undergoing cell death. Specific loss of HSV-1 LAT and neuronal transcripts during quality control filtering indicated widespread destruction of neurons, supporting the presence of contaminating cell-free RNA in other cells following tissue processing. In conclusion, the reported detection of latent HSV-1 in non-neuronal cells is best explained by inaccuracies in the data analyses.

microbiology↗

bioRxiv2021

Low-pathogenic virus induced immunity against TBEV protects mice from disease but not from virus entry into the CNS

Tick-borne encephalitis virus (TBEV) is a leading cause of vector-borne viral encephalitis with expanding endemic regions across Europe. Although currently used inactivated whole virus vaccines are effective, vaccination breakthroughs have been reported for which the reasons are unclear. In this study we tested in mice the efficacy of pre-infection with a closely related low-virulent flavivirus, Langat virus (LGTV strain TP21), or a naturally avirulent TBEV strain (TBEV-280) in providing protection against lethal infection with the highly virulent TBEV strain TBEV-Hypr (referred to as TBEV-Hypr). LGTV has been evaluated as an experimental live vaccine against TBE, but further development was abandoned due to too high residual pathogenicity of a LGTV-based vaccine. Here we show that prior infection with TP21 or TBEV-280 is efficient in protecting mice from lethal TBEV-Hypr challenge. Histopathological analysis of brains from non-immunized control mice revealed neuronal TBEV infection and necrosis. Neuroinflammation, gliosis and neuronal necrosis was however also observed in some of the TP21 and TBEV-280 pre-infected mice although at reduced frequency as compared to the non-immunized TBEV-Hypr infected control mice. Interestingly, qPCR detected the presence of viral RNA in the brains and spinal cord of both TP21 and TBEV-280 immunized mice after TBEV-Hypr challenge, but significantly reduced compared to mock-immunized mice. Our results indicate that although TBEV-Hypr infection is effectively controlled in the periphery upon immunization with low-virulent LGTV or naturally avirulent TBEV-280, it may still enter the CNS of these animals. These findings improve our understanding of potential causes for vaccine failure in individuals vaccinated with TBE vaccines.

immunology↗

bioRxiv2020

Expression of varicella-zoster virus VLT-ORF63 fusion transcript induces broad viral gene expression during reactivation from neuronal latency

Varicella-zoster virus (VZV) establishes lifelong neuronal latency in most humans world-wide, reactivating in one-third to cause herpes zoster and occasionally chronic pain. How VZV establishes, maintains and reactivates from latency is largely unknown. Latent VZV gene expression is restricted to VZV latency-associated transcript (VLT) and open reading frame 63 (ORF63) in naturally VZV-infected human trigeminal ganglia (TG). Notably, these transcript levels positively correlated suggesting co-regulated transcription during latency. Here, we used direct RNA-sequencing to identify fusion transcripts that combine VLT and ORF63 loci (VLT-ORF63) and are expressed during both lytic and latent VZV infections. Furthermore, real-time PCR, RNA in situ hybridization and 5 rapid amplification of cDNA ends (RACE) all confirmed VLT-ORF63, but not canonical ORF63, expression in human TG. During lytic infection, one of the two major VLT-ORF63 isoforms encodes a novel fusion protein combining VLT and ORF63 proteins (pVLT-ORF63). In vitro, VLT is transcribed in latently VZV-infected human sensory neurons, whereas VLT-ORF63 expression is induced by reactivation stimuli. Moreover, the pVLT-ORF63-encoding VLT-ORF63 isoform induced transcription of lytic VZV genes. Collectively, our findings show that VZV expresses a unique set of VLT-ORF63 transcripts, potentially involved in the transition from latency to lytic VZV infection.

microbiology↗

bioRxiv2018

The impact of interspecies recombination on human herpes simplex virus evolution and host immune recognition

Among the most ubiquitous of human pathogens, HSV-1 and HSV-2 are distinct viral species that diverged about six million years ago. At least four ancient HSV-1 x HSV-2 interspecies recombination events have affected the HSV-2 genome, with recombinants and non-recombinants at each locus circulating today. Though interspecies recombination has occurred in the past, its importance in HSV evolution remains incompletely defined. Using 255 newly-sequenced and 219 existing HSV genome sequences, we comprehensively assessed interspecies recombination in HSV. The novel recombinants we identify demonstrate that the sizes and locations of interspecies recombination events in HSV-2 are more variable than previously appreciated. One novel recombinant arose in its current host, showing for the first time that interspecies recombination occurs in contemporary HSV populations. We also demonstrate that interspecies recombination affects T-cell recognition of HSV. Our findings indicate that interspecies recombination can significantly influence genetic variation in and host immunologic response to HSV-2.

genomics↗