Construction and optimization of herpes simplex virus vectors for central nervous system gene delivery based on CRISPR/Cas9-mediated genome editing

2021 ◽  
Vol 21 ◽  
Author(s):  
Xinwei Huang ◽  
Xiuqing Li ◽  
Lijuan Yang ◽  
Pengfei Wang ◽  
Jingyuan Yan ◽  
...  

Aims: We aim to define parameters affecting the safety and long-term transgene expression of attenuated HSV-1 vectors and optimize the expression cassettes to achieve robust and sustained expression in CNS. Background: Engineered, attenuated Herpes simplex virus (HSV) vectors are promising vehicles for gene delivery to the peripheral and central nervous systems. The virus latent promoter (LAP) is commonly used to drive exogenous gene expression; however, parameters affecting the safety and long-term transgene expression of attenuated HSV-1 vectors have not been fully understood. Objective: This study aimed to construct attenuated HSV-1 vectors using the CRISPR-Cas9 system and examine the influence of transgene cassette construction and insertion site on transgene expression and vector safety. Method: In this study, we used a CRISPR-Cas9 system to accurately and efficiently edit attenuated HSV-1 strain 1716, and constructed two series of recombinant virus LMR and LMRx with different sets of gene cassettes insertion in Exon1(LAP2) and 2.0 kb intron downstream of LAP, respectively. The transgene expression and viral gene transcriptional kinetics were compared in in-vitro cell lines. The reporter gene expression and safety profiles of each vector were further evaluated in the mouse hippocampus gene transduction model. Result: The in-vitro cell line analysis indicated that the insertion of a gene expression cassette would disrupt virus gene transcription. Mouse hippocampus transducing analysis suggested that complete expression cassette insertion at 2.0 kb intron could achieve robust and longtime gene expression than the other constructs. Recombinants with gene expression cassettes lacked Poly (A), which induced significant neuronal inflammation due to persistent viral antigen expression and microglia activation. Conclusion: Our results indicated that the integrity of LAT transcripts was not necessary for the establishment of long-term latent expression. Exogenous strong promoters (like cBh promoter) could remain active during latency when placed in Exon1 or 2.0 Kb Intron of LAT locus, although their transcriptional activity declined with time. Consistent with previous research, the foreign gene expression would last much longer when the gene cassette was located downstream of Exon1, which suggested a role of LAP2 in maintaining promoter activity during latency. Besides, over-transcription of the downstream part of LAT may induce continuous activation of the attenuated vectors, suggesting an important role of LAT in maintaining viral reactivation potential.

1999 ◽  
Vol 73 (5) ◽  
pp. 4171-4180 ◽  
Author(s):  
Ying-Hsiu Su ◽  
Rupalie L. Meegalla ◽  
Rohini Chowhan ◽  
Christopher Cubitt ◽  
John E. Oakes ◽  
...  

ABSTRACT A two-cell system for the stimulation of herpes simplex virus type 1 (HSV-1) from an in vitro model of long-term (quiescent) infection is described. Rat pheochromocytoma (PC12) cells differentiated with nerve growth factor were infected with HSV-1 strain 17. Little, if any, cytotoxicity was observed, and a quiescent infection was established. The long-term infection was characterized by the absence of all detectable virus in the culture medium and little, if any, detectable early or late viral-gene expression as determined by reverse transcriptase PCR analysis. The presence of HSV-1 DNA was determined by PCR analysis. This showed that approximately 180 viral genomes were present in limiting dilutions where as few as 16 cells were examined. The viral DNA was infectious, since cocultivation with human corneal fibroblasts (HCF) or human corneal epithelial cells (HCE) resulted in recovery of virus from most, if not all, clusters of PC12 cells. Following cocultivation, viral antigens appeared first on PC12 cells and then on neighboring inducing cells, as determined by immunofluorescent staining, demonstrating that de novo viral protein synthesis first occurred in the long-term-infected PC12 cells. Interestingly, the ability to induce HSV varied among the cell lines tested. For example, monkey kidney CV-1 cells and human hepatoblastoma HepG2 cells, but not mouse neuroblastoma cells or undifferentiated PC12 cells, mediated stimulation. This work thus shows that (i) quiescent HSV infections can be maintained in PC12 cells in vitro, (ii) HSV can be induced from cells which do not accumulate significant levels of latency-associated transcripts, and (iii) the activation of HSV gene expression can be induced via neighboring cells. The ability of adjacent cells to stimulate HSV gene expression in neuron-like cells represents a novel area of study. The mechanism(s) whereby HCF, HCE, and HepG2 and CV-1 cells communicate with PC12 cells and stimulate viral replication, as well as how this system compares with other in vitro models of long-term infection, is discussed.


2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Elena Criscuolo ◽  
Matteo Castelli ◽  
Roberta A. Diotti ◽  
Virginia Amato ◽  
Roberto Burioni ◽  
...  

ABSTRACTHerpes simplex virus 1 (HSV-1) and HSV-2 can evade serum antibody-mediated neutralization through cell-to-cell transmission mechanisms, which represent one of the central steps in disease reactivation. To address the role of humoral immunity in controlling HSV-1 and HSV-2 replication, we analyzed serum samples from 44 HSV-1 and HSV-2 seropositive subjects by evaluating (i) their efficiency in binding both the purified viral particles and recombinant gD and gB viral glycoproteins, (ii) their neutralizing activity, and (iii) their capacity to inhibit the cell-to-cell virus passagein vitro. All of the sera were capable of binding gD, gB, and whole virions, and all sera significantly neutralized cell-free virus. However, neither whole sera nor purified serum IgG fraction was able to inhibit significantly cell-to-cell virus spreading inin vitropost-virus-entry infectious assays. Conversely, when spiked with an already described anti-gD human monoclonal neutralizing antibody capable of inhibiting HSV-1 and -2 cell-to-cell transmission, each serum boosted both its neutralizing and post-virus-entry inhibitory activity, with no interference exerted by serum antibody subpopulations.IMPORTANCEDespite its importance in the physiopathology of HSV-1 and -2 infections, the cell-to-cell spreading mechanism is still poorly understood. The data shown here suggest that infection-elicited neutralizing antibodies capable of inhibiting cell-to-cell virus spread can be underrepresented in most infected subjects. These observations can be of great help in better understanding the role of humoral immunity in controlling virus reactivation and in the perspective of developing novel therapeutic strategies, studying novel correlates of protection, and designing effective vaccines.


2000 ◽  
Vol 74 (2) ◽  
pp. 956-964 ◽  
Author(s):  
Ker R. Marshall ◽  
Robin H. Lachmann ◽  
Stacey Efstathiou ◽  
Angela Rinaldi ◽  
Chris M. Preston

ABSTRACT The role of viral immediate-early (IE) gene expression in herpes simplex virus type 1 (HSV-1) latency was investigated. The HSV-1 multiple mutant in1312, defective for the expression of the virion transactivator VP16 and the IE proteins ICP0 and ICP4, was used as the parent for these studies. The coding sequences of theEscherichia coli lacZ gene, preceded by the encephalomyocarditis virus internal ribosome entry site, were inserted into the region of in1312 that encodes the latency-associated transcripts (LATs) such that transcription of the transgene was controlled by the LAT promoter. This insert has previously been shown to direct long-term latent-phase expression of β-galactosidase in a wild-type HSV-1 genome (R. H. Lachmann and S. Efstathiou, J. Virol. 71, 3197–3207, 1997). The resulting recombinant, in1388, was apathogenic after inoculation into mice via the footpad and did not detectably replicate in dorsal root ganglia (DRG) or footpads. Mutant in1388 established latency in DRG, and β-galactosidase was expressed in increasing numbers of neurons over the first 25 days of infection. During latency, more than 1% of neurons in ganglia that innervate the footpad expressed β-galactosidase, with the number of positive cells remaining constant for at least 5 months. Rescue of the VP16, ICP0, or ICP4 mutations of in1388 did not affect the number of β-galactosidase-expressing neurons detected during latency. The results demonstrate that HSV-1 mutants severely impaired for IE gene expression are capable of establishing latency and efficiently expressing a foreign gene product under control of the LAT promoter.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 196
Author(s):  
Sara Artusi ◽  
Emanuela Ruggiero ◽  
Matteo Nadai ◽  
Beatrice Tosoni ◽  
Rosalba Perrone ◽  
...  

The herpes simplex virus 1 (HSV-1) genome is extremely rich in guanine tracts that fold into G-quadruplexes (G4s), nucleic acid secondary structures implicated in key biological functions. Viral G4s were visualized in HSV-1 infected cells, with massive virus cycle-dependent G4-formation peaking during viral DNA replication. Small molecules that specifically interact with G4s have been shown to inhibit HSV-1 DNA replication. We here investigated the antiviral activity of TMPyP4, a porphyrin known to interact with G4s. The analogue TMPyP2, with lower G4 affinity, was used as control. We showed by biophysical analysis that TMPyP4 interacts with HSV-1 G4s, and inhibits polymerase progression in vitro; in infected cells, it displayed good antiviral activity which, however, was independent of inhibition of virus DNA replication or entry. At low TMPyP4 concentration, the virus released by the cells was almost null, while inside the cell virus amounts were at control levels. TEM analysis showed that virus particles were trapped inside cytoplasmatic vesicles, which could not be ascribed to autophagy, as proven by RT-qPCR, western blot, and immunofluorescence analysis. Our data indicate a unique mechanism of action of TMPyP4 against HSV-1, and suggest the unprecedented involvement of currently unknown G4s in viral or antiviral cellular defense pathways.


2012 ◽  
Vol 86 (16) ◽  
pp. 8592-8601 ◽  
Author(s):  
Charlotte Mahiet ◽  
Ayla Ergani ◽  
Nicolas Huot ◽  
Nicolas Alende ◽  
Ahmed Azough ◽  
...  

Herpes simplex virus 1 (HSV-1) is a human pathogen that leads to recurrent facial-oral lesions. Its 152-kb genome is organized in two covalently linked segments, each composed of a unique sequence flanked by inverted repeats. Replication of the HSV-1 genome produces concatemeric molecules in which homologous recombination events occur between the inverted repeats. This mechanism leads to four genome isomers (termed P, IS, IL, and ILS) that differ in the relative orientations of their unique fragments. Molecular combing analysis was performed on DNA extracted from viral particles and BSR, Vero, COS-7, and Neuro-2a cells infected with either strain SC16 or KOS of HSV-1, as well as from tissues of experimentally infected mice. Using fluorescence hybridization, isomers were repeatedly detected and distinguished and were accompanied by a large proportion of noncanonical forms (40%). In both cell and viral-particle extracts, the distributions of the four isomers were statistically equivalent, except for strain KOS grown in Vero and Neuro-2a cells, in which P and IS isomers were significantly overrepresented. In infected cell extracts, concatemeric molecules as long as 10 genome equivalents were detected, among which, strikingly, the isomer distributions were equivalent, suggesting that any such imbalance may occur during encapsidation.In vivo, for strain KOS-infected trigeminal ganglia, an unbalanced distribution distinct from the onein vitrowas observed, along with a considerable proportion of noncanonical assortment.


2003 ◽  
Vol 77 (5) ◽  
pp. 3307-3311 ◽  
Author(s):  
Sarah M. Richart ◽  
Scott A. Simpson ◽  
Claude Krummenacher ◽  
J. Charles Whitbeck ◽  
Lewis I. Pizer ◽  
...  

ABSTRACT Primary cultures of rat and mouse sensory neurons were used to study the entry of herpes simplex virus type 1 (HSV-1). Soluble, truncated nectin-1 but not HveA prevented viral entry. Antibodies against nectin-1 also blocked infection of rat neurons. These results indicate that nectin-1 is the primary receptor for HSV-1 infection of sensory neurons.


2016 ◽  
Vol 90 (19) ◽  
pp. 8621-8633 ◽  
Author(s):  
Elizabeth Sloan ◽  
Anne Orr ◽  
Roger D. Everett

ABSTRACTWe previously reported that MORC3, a protein associated with promyelocytic leukemia nuclear bodies (PML NBs), is a target of herpes simplex virus 1 (HSV-1) ICP0-mediated degradation (E. Sloan, et al., PLoS Pathog11:e1005059, 2015,http://dx.doi.org/10.1371/journal.ppat.1005059). Since it is well known that certain other components of the PML NB complex play an important role during an intrinsic immune response to HSV-1 and are also degraded or inactivated by ICP0, here we further investigate the role of MORC3 during HSV-1 infection. We demonstrate that MORC3 has antiviral activity during HSV-1 infection and that this antiviral role is counteracted by ICP0. In addition, MORC3's antiviral role extends to wild-type (wt) human cytomegalovirus (HCMV) infection, as its plaque-forming efficiency increased in MORC3-depleted cells. We found that MORC3 is recruited to sites associated with HSV-1 genomes after their entry into the nucleus of an infected cell, and in wt infections this is followed by its association with ICP0 foci prior to its degradation. The RING finger domain of ICP0 was required for degradation of MORC3, and we confirmed that no other HSV-1 protein is required for the loss of MORC3. We also found that MORC3 is required for fully efficient recruitment of PML, Sp100, hDaxx, and γH2AX to sites associated with HSV-1 genomes entering the host cell nucleus. This study further unravels the intricate ways in which HSV-1 has evolved to counteract the host immune response and reveals a novel function for MORC3 during the host intrinsic immune response.IMPORTANCEHerpesviruses have devised ways to manipulate the host intrinsic immune response to promote their own survival and persistence within the human population. One way in which this is achieved is through degradation or functional inactivation of PML NB proteins, which are recruited to viral genomes in order to repress viral transcription. Because MORC3 associates with PML NBs in uninfected cells and is a target for HSV-1-mediated degradation, we investigated the role of MORC3 during HSV-1 infection. We found that MORC3 is also recruited to viral HSV-1 genomes, and importantly it contributes to the fully efficient recruitment of PML, hDaxx, Sp100, and γH2AX to these sites. Depletion of MORC3 resulted in an increase in ICP0-null HSV-1 and wt HCMV replication and plaque formation; therefore, this study reveals that MORC3 is an antiviral factor which plays an important role during HSV-1 and HCMV infection.


2007 ◽  
Vol 82 (6) ◽  
pp. 2661-2672 ◽  
Author(s):  
Roger D. Everett ◽  
Carlos Parada ◽  
Philippe Gripon ◽  
Hüseyin Sirma ◽  
Anne Orr

ABSTRACT Herpes simplex virus type 1 (HSV-1) mutants that fail to express the viral immediate-early protein ICP0 have a pronounced defect in viral gene expression and plaque formation in limited-passage human fibroblasts. ICP0 is a RING finger E3 ubiquitin ligase that induces the degradation of several cellular proteins. PML, the organizer of cellular nuclear substructures known as PML nuclear bodies or ND10, is one of the most notable proteins that is targeted by ICP0. Depletion of PML from human fibroblasts increases ICP0-null mutant HSV-1 gene expression, but not to wild-type levels. In this study, we report that depletion of Sp100, another major ND10 protein, results in a similar increase in ICP0-null mutant gene expression and that simultaneous depletion of both proteins complements the mutant virus to a greater degree. Although chromatin assembly and modification undoubtedly play major roles in the regulation of HSV-1 infection, we found that inhibition of histone deacetylase activity with trichostatin A was unable to complement the defect of ICP0-null mutant HSV-1 in either normal or PML-depleted human fibroblasts. These data lend further weight to the hypothesis that ND10 play an important role in the regulation of HSV-1 gene expression.


1995 ◽  
Vol 39 (4) ◽  
pp. 846-849 ◽  
Author(s):  
H Aoki ◽  
T Akaike ◽  
K Abe ◽  
M Kuroda ◽  
S Arai ◽  
...  

Oryzacystatin (OC) is the first-described cystatin originating from rice seed; it consists of two molecular species, OC-I and OC-II, which have antiviral action against poliovirus in vitro (H. Kondo, S. Ijiri, K. Abe, H. Maeda, and S. Arai, FEBS Lett. 299:48-50, 1992). In the experiments reported here, we investigated the effects of OC-I and OC-II on the replication of herpes simplex virus type 1 (HSV-1) in vitro and in vivo. HSV-1 was inoculated onto monolayers of monkey kidney epithelial cells (CV-1 cells) at a multiplicity of infection of 0.1 PFU per cell. After adsorption of the virus onto cells, the cultures were incubated in the presence of either OC-I or OC-II in the concentration range of 1.0 to 300 microM, and the supernatant virus yield was quantitated at 24 h. The effective concentration for 90% inhibition of HSV-1 was 14.8 microM, while a cytotoxic effect on CV-1 cells without infection of HSV-1 was not observed below 500 microM OC-I. Therefore, the apparent in vitro chemotherapeutic index was estimated to be more than 33. In the mouse model of HSV-1-induced keratitis and encephalopathy, topical administration of OC-I to the mouse cornea produced a significant decrease in virus production in the cornea (mean virus yields: 3.11 log10 PFU in the treated group and 4.37 log10 PFU in the control group) and significant improvement in survival rates (P = 0.01). The in vivo antiherpetic effect of OC-I was comparable to that of acyclovir, indicating that topical treatment of HSV-1 infection in humans with OC-I might be possible. Our data also suggest the importance of some thiol proteinases, which may be derived from either the host's cells or HSV-1, during the replication process of HSV-1.


Sign in / Sign up

Export Citation Format

Share Document