scholarly journals Release of HSV-1 Cell-Free Virions: Mechanisms, Regulation, and Likely Role in Human-Human Transmission

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2395
Author(s):  
Stephen A. Rice
Keyword(s):  
The Body ◽  
Viral Reactivation ◽  
Target Cells ◽  
Extracellular Milieu ◽  
Viral Spread ◽  
Virion Release ◽  
Cell Spread ◽  
Hsv 1 ◽  
Cell Cell

Herpes simplex virus type 1, or HSV-1, is a widespread human pathogen that replicates in epithelial cells of the body surface and then establishes latent infection in peripheral neurons. When HSV-1 replicates, viral progeny must be efficiently released to spread infection to new target cells. Viral spread occurs via two major routes. In cell-cell spread, progeny virions are delivered directly to cellular junctions, where they infect adjacent cells. In cell-free release, progeny virions are released into the extracellular milieu, potentially allowing the infection of distant cells. Cell-cell spread of HSV-1 has been well studied and is known to be important for in vivo infection and pathogenesis. In contrast, HSV-1 cell-free release has received less attention, and its significance to viral biology is unclear. Here, I review the mechanisms and regulation of HSV-1 cell-free virion release. Based on knowledge accrued in other herpesviral systems, I argue that HSV-1 cell-free release is likely to be tightly regulated in vivo. Specifically, I hypothesize that this process is generally suppressed as the virus replicates within the body, but activated to high levels at sites of viral reactivation, such as the oral mucosa and skin, in order to promote efficient transmission of HSV-1 to new human hosts.

scholarly journals OOCHIP: Compartmentalized Microfluidic Perfusion System with Porous Barriers for Enhanced Cell–Cell Crosstalk in Organ-on-a-Chip

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 565
Author(s):  
Qasem Ramadan ◽  
Sajay Bhuvanendran Nair Gourikutty ◽  
Qingxin Zhang
Keyword(s):  
Drug Efficacy ◽  
Human Adipose Tissue ◽  
Cell Types ◽  
Cell Interaction ◽  
The Body ◽  
Close Proximity ◽  
Porous Barriers ◽  
Cell Cell

Improved in vitro models of human organs for predicting drug efficacy, interactions, and disease modelling are crucially needed to minimize the use of animal models, which inevitably display significant differences from the human disease state and metabolism. Inside the body, cells are organized either in direct contact or in close proximity to other cell types in a tightly controlled architecture that regulates tissue function. To emulate this cellular interface in vitro, an advanced cell culture system is required. In this paper, we describe a set of compartmentalized silicon-based microfluidic chips that enable co-culturing several types of cells in close proximity with enhanced cell–cell interaction. In vivo-like fluid flow into and/or from each compartment, as well as between adjacent compartments, is maintained by micro-engineered porous barriers. This porous structure provides a tool for mimicking the paracrine exchange between cells in the human body. As a demonstrating example, the microfluidic system was tested by culturing human adipose tissue that is infiltrated with immune cells to study the role if the interplay between the two cells in the context of type 2 diabetes. However, the system provides a platform technology for mimicking the structure and function of single- and multi-organ models, which could significantly narrow the gap between in vivo and in vitro conditions.

scholarly journals Herpes Simplex Virus with Highly Reduced gD Levels Can Efficiently Enter and Spread between Human Keratinocytes

2001 ◽  
Vol 75 (21) ◽  
pp. 10309-10318 ◽  
Author(s):  
Mary T. Huber ◽  
Todd W. Wisner ◽  
Nagendra R. Hegde ◽  
Kimberley A. Goldsmith ◽  
Daniel A. Rauch ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cultured Cells ◽  
Human Keratinocytes ◽  
Hacat Cells ◽  
Wild Type ◽  
Simplex Virus ◽  
Cell Spread ◽  
Hsv 1

ABSTRACT The rapid spread of herpes simplex virus type 1 (HSV-1) in mucosal epithelia and neuronal tissue depends primarily on the ability of the virus to navigate within polarized cells and the tissues they constitute. To understand HSV entry and the spread of virus across cell junctions, we have previously characterized a human keratinocyte cell line, HaCaT. These cells appear to reflect cells infected in vivo more accurately than many of the cultured cells used to propagate HSV. HSV mutants lacking gE/gI are highly compromised in spread within epithelial and neuronal tissues and also show defects in cell-to-cell spread in HaCaT cells, but not in other, nonpolarized cells. HSV gD is normally considered absolutely essential for entry and cell-to-cell spread, both in cultured cells and in vivo. Here, an HSV-1 gD mutant virus, F-US6kan, was found to efficiently enter HaCaT cells and normal human keratinocytes and could spread from cell to cell without gD provided by complementing cells. By contrast, entry and spread into other cells, especially highly transformed cells commonly used to propagate HSV, were extremely inefficient. Further analyses of F-US6kan indicated that this mutant expressed extraordinarily low (1/500 wild-type) levels of gD. Neutralizing anti-gD monoclonal antibodies inhibited entry of F-US6kan, suggesting F-US6kan utilized this small amount of gD to enter cells. HaCaT cells expressed high levels of an HSV gD receptor, HveC, and entry of F-US6kan into HaCaT cells could also be inhibited with antibodies specific for HveC. Interestingly, anti-HveC antibodies were not fully able to inhibit entry of wild-type HSV-1 into HaCaT cells. These results help to uncover important properties of HSV and human keratinocytes. HSV, with exceedingly low levels of a crucial receptor-binding glycoprotein, can enter cells expressing high levels of receptor. In this case, surplus gD may be useful to avoid neutralization by anti-gD antibodies.

scholarly journals Herpes Simplex Virus 1 Spread in Oligodendrocytic Cells Is Highly Dependent on MAL Proteolipid

2019 ◽  
Vol 94 (4) ◽  
Author(s):  
José Antonio López-Guerrero ◽  
Carmen de la Nuez ◽  
Beatriz Praena ◽  
Enrique Sánchez-León ◽  
Claude Krummenacher ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Critical Role ◽  
Herpes Simplex Virus 1 ◽  
Cell Contacts ◽  
Viral Spread ◽  
First Case ◽  
Simplex Virus ◽  
Cell Spread ◽  
Hsv 1

ABSTRACT Myelin and lymphocyte protein (MAL) is a tetraspan integral membrane protein that resides in detergent-insoluble membrane fractions enriched in condensed membranes. MAL is expressed in oligodendrocytes, in Schwann cells, where it is essential for the stability of myelin, and at the apical membrane of epithelial cells, where it has a critical role in transport. In T lymphocytes, MAL is found at the immunological synapse and plays a crucial role in exosome secretion. However, no involvement of MAL in viral infections has been reported so far. Here, we show that herpes simplex virus 1 (HSV-1) virions travel in association with MAL-positive structures to reach the end of cellular processes, which contact uninfected oligodendrocytes. Importantly, the depletion of MAL led to a significant decrease in infection, with a drastic reduction in the number of lytic plaques in MAL-silenced cells. These results suggest a significant role for MAL in viral spread at cell contacts. The participation of MAL in the cell-to-cell spread of HSV-1 may shed light on the involvement of proteolipids in this process. IMPORTANCE Herpes simplex virus 1 (HSV-1) is a neurotropic pathogen that can infect many types of cells and establish latent infections in neurons. HSV-1 may spread from infected to uninfected cells by two main routes: by cell-free virus or by cell-to-cell spread. In the first case, virions exit into the extracellular space and then infect another cell from the outside. In the second case, viral transmission occurs through cell-to-cell contacts via a mechanism that is still poorly understood. A third mode of spread, using extracellular vesicles, also exists. In this study, we demonstrate the important role for a myelin protein, myelin and lymphocyte protein (MAL), in the process of cell-to-cell viral spread in oligodendrocytes. We show that MAL is involved in trafficking of virions along cell processes and that MAL depletion produces a significant alteration in the viral cycle, which reduces cell-to cell spread of HSV-1.

scholarly journals X-ray induced photodynamic therapy with copper-cysteamine nanoparticles in mice tumors

2019 ◽  
Vol 116 (34) ◽  
pp. 16823-16828 ◽  
Author(s):  
Samana Shrestha ◽  
Jing Wu ◽  
Bindeshwar Sah ◽  
Adam Vanasse ◽  
Leon N Cooper ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Treatment Method ◽  
The Body ◽  
Target Cells ◽  
X Rays ◽  
X Ray ◽  
Mouse Tumors ◽  
Study Results ◽  
New Type

Photodynamic therapy (PDT), a treatment that uses a photosensitizer, molecular oxygen, and light to kill target cells, is a promising cancer treatment method. However, a limitation of PDT is its dependence on light that is not highly penetrating, precluding the treatment of tumors located deep in the body. Copper-cysteamine nanoparticles are a new type of photosensitizer that can generate cytotoxic singlet oxygen molecules upon activation by X-rays. In this paper, we report on the use of copper-cysteamine nanoparticles, designed to be targeted to tumors, for X-ray–induced PDT. In an in vivo study, results show a statistically significant reduction in tumor size under X-ray activation of pH-low insertion peptide–conjugated, copper-cysteamine nanoparticles in mouse tumors. This work confirms the effectiveness of copper-cysteamine nanoparticles as a photosensitizer when activated by radiation and suggests that these Cu-Cy nanoparticles may be good candidates for PDT in deeply seated tumors when combined with X-rays and conjugated to a tumor-targeting molecule.

scholarly journals Contact-Induced Mitochondrial Polarization Supports HIV-1 Virological Synapse Formation

2014 ◽  
Vol 89 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Elisabetta Groppelli ◽  
Shimona Starling ◽  
Clare Jolly
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Virological Synapse ◽  
Cell Contact ◽  
Target Cells ◽  
Cell Contacts ◽  
Cell Spread ◽  
Hiv 1 ◽  
Cell Cell

ABSTRACTRapid HIV-1 spread between CD4 T lymphocytes occurs at retrovirus-induced immune cell contacts called virological synapses (VS). VS are associated with striking T cell polarization and localized virus budding at the site of contact that facilitates cell-cell spread. In addition to this, spatial clustering of organelles, including mitochondria, to the contact zone has been previously shown. However, whether cell-cell contact specifically induces dynamic T cell remodeling during VS formation and what regulates this process remain unclear. Here, we report that contact between an HIV-1-infected T cell and an uninfected target T cell specifically triggers polarization of mitochondria concomitant with recruitment of the major HIV-1 structural protein Gag to the site of cell-cell contact. Using fixed and live-cell imaging, we show that mitochondrial and Gag polarization in HIV-1-infected T cells occurs within minutes of contact with target T cells, requires the formation of stable cell-cell contacts, and is an active, calcium-dependent process. We also find that perturbation of mitochondrial polarization impairs cell-cell spread of HIV-1 at the VS. Taken together, these data suggest that HIV-1-infected T cells are able to sense and respond to contact with susceptible target cells and undergo dynamic cytoplasmic remodeling to create a synaptic environment that supports efficient HIV-1 VS formation between CD4 T lymphocytes.IMPORTANCEHIV-1 remains one of the major global health challenges of modern times. The capacity of HIV-1 to cause disease depends on the virus's ability to spread between immune cells, most notably CD4 T lymphocytes. Cell-cell transmission is the most efficient way of HIV-1 spread and occurs at the virological synapse (VS). The VS forms at the site of contact between an infected cell and an uninfected cell and is characterized by polarized assembly and budding of virions and clustering of cellular organelles, including mitochondria. Here, we show that cell-cell contact induces rapid recruitment of mitochondria to the contact site and that this supports efficient VS formation and consequently cell-cell spread. Additionally, we observed that cell-cell contact induces a mitochondrion-dependent increase in intracellular calcium, indicative of cellular signaling. Taken together, our data suggest that VS formation is a regulated process and thus a potential target to block HIV-1 cell-cell spread.

scholarly journals Roles of the Phosphorylation of Herpes Simplex Virus 1 UL51 at a Specific Site in Viral Replication and Pathogenicity

2018 ◽  
Vol 92 (18) ◽  
Author(s):  
Akihisa Kato ◽  
Shinya Oda ◽  
Mizuki Watanabe ◽  
Masaaki Oyama ◽  
Hiroko Kozuka-Hata ◽  
...  
Keyword(s):  
Viral Replication ◽  
Cell Cultures ◽  
Phosphorylation Sites ◽  
Hacat Cells ◽  
Herpes Simplex Virus 1 ◽  
Infected Cells ◽  
Simplex Virus ◽  
Cell Spread ◽  
Hsv 1 ◽  
Cell Cell

ABSTRACTHerpes simplex virus 1 (HSV-1) UL51 is a phosphoprotein that functions in the final envelopment in the cytoplasm and viral cell-cell spread, leading to efficient viral replication in cell cultures. To clarify the mechanism by which UL51 is regulated in HSV-1-infected cells, we focused on the phosphorylation of UL51. Mass spectrometry analysis of purified UL51 identified five phosphorylation sites in UL51. Alanine replacement of one of the identified phosphorylation sites in UL51, serine 184 (Ser-184), but not the other identified phosphorylation sites, significantly reduced viral replication and cell-cell spread in HaCaT cells. This mutation induced membranous invaginations adjacent to the nuclear membrane, the accumulation of primary enveloped virions in the invaginations and perinuclear space, and mislocalized UL34 and UL31 in punctate structures at the nuclear membrane; however, it had no effect on final envelopment in the cytoplasm of HaCaT cells. Of note, the alanine mutation in UL51 Ser-184 significantly reduced the mortality of mice following ocular infection. Phosphomimetic mutation in UL51 Ser-184 partly restored the wild-type phenotype in cell cultures and in mice. Based on these results, we concluded that some UL51 functions are specifically regulated by phosphorylation at Ser-184 and that this regulation is critical for HSV-1 replication in cell cultures and pathogenicityin vivo.IMPORTANCEHSV-1 UL51 is conserved in all members of theHerpesviridaefamily. This viral protein is phosphorylated and functions in viral cell-cell spread and cytoplasmic virion maturation in HSV-1-infected cells. Although the downstream effects of HSV-1 UL51 have been clarified, there is a lack of information on how this viral protein is regulated as well as the significance of the phosphorylation of this protein in HSV-1-infected cells. In this study, we show that the phosphorylation of UL51 at Ser-184 promotes viral replication, cell-cell spread, and nuclear egress in cell cultures and viral pathogenicity in mice. This is the first report to identify the mechanism by which UL51 is regulated as well as the significance of UL51 phosphorylation in HSV-1 infection. Our study may provide insights into the regulatory mechanisms of other herpesviral UL51 homologs.

scholarly journals EPIDEMIOLOGICAL, TOXICOLOGICAL AND MOLEСULAR-GENETIC ASPECTS OF ENDOCRINE DISRUPTING CHEMICALS IN THE CHEMICAL SAFETY PROBLEM

2018 ◽  
Vol 97 (3) ◽  
pp. 197-203
Author(s):  
Oksana O. Sinitsyna ◽  
Yu. A. Rakhmanin ◽  
Z. I. Zholdakova ◽  
M. G. Aksenova ◽  
A. V. Kirillov ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Structural Features ◽  
The Body ◽  
Target Cells ◽  
Chemical Safety ◽  
Endocrine Disrupting ◽  
The Impact

The literature review has shown the problem of endocrine disrupting chemicals (EDC) to be associated with their wide distribution in the environment, the abundance, and variety of the chemical structure. Three leading mechanisms of EDCs action are identified as follows: imitation of the naturally occurring hormones action, blocking of receptors within the target cells of hormones, the impact of their kinetics in the body. Epidemiological studies indicate an increase in diseases caused by a disorder of the hormonal system. They are associated with the effect of EDCs. Substances that are completely dissimilar in chemical structure can cause the same effects. According to WHO [6], it is impossible, based on the chemical structure, to determine whether a substance is a disruptor of the endocrine system. However, some structural features determine the estrogenic, thyreogenic and glucocorticoid activity of chemicals. Hence, the need to differentiate the specific (primary) effect of a chemical substance on the endocrine system and the indirect (secondary) effect on it via other mechanisms comes to the fore. In own research, specific mechanisms were shown to be determined in the experiment when studying the complexity of effects, taking into account the processes of adaptation and decompensation, and identifying the effects manifested with the lowest doses. One of the methodological approaches can be the developed “structure-biotransformation-activity” prediction system aimed at revealing the primary types of effects: using quantum-chemical calculations and the plausible reasoning class (called the JSM-reasoning in honour of John Stuart Mill) logico-combinatorial method, it was possible to identify structural fragments of substances responsible for the manifestation of carcinogenic, allergenic effects, methemoglobin formation, etc. The results of clinical studies show the use of pharmacological drugs as models for in vivo study of the effects of EDC to allow not only studying atypical mechanisms of the impact of EDCs from the point of view of molecular genetics but also to predict the individual susceptibility to them taking into account polymorphism of candidate genes. The EDCs problem poses the need for a complex of interdisciplinary research, including three main relationships: exposure assessment-biomonitoring data-the prevalence of endocrine-dependent diseases, taking into account the qualitative and quantitative contribution of individual endocrine disrupters to the development of an ecologically dependent endocrine pathology using molecular genetic methods.

scholarly journals Herpesvirus Entry Mediator HVEM Mediates Cell-Cell Spread in BHK(TK−) Cell Clones

1998 ◽  
Vol 72 (2) ◽  
pp. 1411-1417 ◽  
Author(s):  
Richard J. Roller ◽  
Daniel Rauch
Keyword(s):  
Cell Lines ◽  
Pseudorabies Virus ◽  
Cell Types ◽  
Single Step ◽  
Cell Clones ◽  
Step Growth ◽  
Simplex Virus ◽  
Cell Spread ◽  
Hsv 1 ◽  
Cell Cell

ABSTRACT 95-19 and US11cl19.3 are BHK(TK−)-derived cell lines that are highly resistant to postattachment entry of herpes simplex virus type 1 (HSV-1) and HSV-2 but not to later steps in single-step replication. The resistance properties of these two cell types are not identical. US11cl19.3 cells are fully susceptible to pseudorabies virus (PRV), as shown by single-step growth experiments, whereas 95-19 cells are resistant to entry of free PRV but not to entry by cell-cell spread. We have tested the ability of HVEM to overcome the block to infection in both cell lines following transient and stable transfection. HVEM was able to mediate entry of free HSV-1 into both cell lines, as shown by an increase in the number of β-galactosidase-expressing cells in cultures transiently transfected with an HVEM expression plasmid and infected withlacZ-expressing HSV-1. In stably transfected 95-19 cells, HVEM enhanced infection by free HSV-1, as shown by an increase in the number of infectious centers obtained following infection. In both cell types, HVEM strongly enhanced entry of HSV-1 and HSV-2 by cell-cell spread, suggesting that HVEM can function as an entry mediator both in entry of free virus and in entry by cell-cell spread.

scholarly journals Multiple Roles of the Cytoplasmic Domain of Herpes Simplex Virus 1 Envelope Glycoprotein D in Infected Cells

2016 ◽  
Vol 90 (22) ◽  
pp. 10170-10181 ◽  
Author(s):  
Jun Arii ◽  
Keiko Shindo ◽  
Naoto Koyanagi ◽  
Akihisa Kato ◽  
Yasushi Kawaguchi
Keyword(s):  
Plasma Membrane ◽  
Viral Replication ◽  
Viral Entry ◽  
Envelope Glycoprotein ◽  
Cytoplasmic Domain ◽  
Herpes Simplex Virus 1 ◽  
Infected Cells ◽  
Cell Spread ◽  
Hsv 1 ◽  
Cell Cell

ABSTRACTHerpes simplex virus 1 (HSV-1) envelope glycoprotein D (gD) plays an essential role in viral entry. The functional regions of gD responsible for viral entry have been mapped to its extracellular domain, whereas the gD cytoplasmic domain plays no obvious role in viral entry. Thus far, the role(s) of the gD cytoplasmic domain in HSV-1 replication has remained to be elucidated. In this study, we show that ectopic expression of gD induces microvillus-like tubular structures at the plasma membrane which resemble the reported projection structures of the plasma membrane induced in HSV-1-infected cells. Mutations in the arginine cluster (residues 365 to 367) in the gD cytoplasmic domain greatly reduced gD-induced plasma membrane remodeling. In agreement with this, the mutations in the arginine cluster in the gD cytoplasmic domain reduced the number of microvillus-like tubular structures at the plasma membrane in HSV-1-infected cells. In addition, the mutations produced an accumulation of unenveloped nucleocapsids in the cytoplasm and reduced viral replication and cell-cell spread. These results suggest that the arginine cluster in the gD cytoplasmic domain is required for the efficient induction of plasma membrane projections and viral final envelopment, and these functions of the gD domain may lead to efficient viral replication and cell-cell spread.IMPORTANCEThe cytoplasmic domain of HSV-1 gD, an envelope glycoprotein essential for viral entry, was reported to promote viral replication and cell-cell spread, but the role(s) of the domain during HSV-1 infection has remained unknown. In this study, we clarify two functions of the arginine cluster in the HSV-1 gD cytoplasmic domain, both of which require host cell membrane remodeling, i.e., the formation of microvillus-like projections at the plasma membrane and viral final envelopment in HSV-1-infected cells. We also show that the gD arginine cluster is required for efficient HSV-1 replication and cell-cell spread. This is the first report clarifying not only the functions of the gD cytoplasmic domain but also identifying the gD arginine cluster to be the HSV-1 factor responsible for the induction of plasma membrane projections in HSV-1-infected cells. Our results elucidate some of the functions of this multifunctional envelope glycoprotein during HSV-1 infection.

scholarly journals Recurrent Herpes Simplex Virus Type 1 (HSV-1) Infection Modulates Neuronal Aging Marks in In Vitro and In Vivo Models

2021 ◽  
Vol 22 (12) ◽  
pp. 6279
Author(s):  
Giorgia Napoletani ◽  
Virginia Protto ◽  
Maria Elena Marcocci ◽  
Lucia Nencioni ◽  
Anna Teresa Palamara ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Molecular Mechanisms ◽  
Neuronal Response ◽  
Viral Reactivation ◽  
In Vivo Models ◽  
Simplex Virus ◽  
Hsv 1

Herpes simplex virus 1 (HSV-1) is a widespread neurotropic virus establishing a life-long latent infection in neurons with periodic reactivations. Recent studies linked HSV-1 to neurodegenerative processes related to age-related disorders such as Alzheimer’s disease. Here, we explored whether recurrent HSV-1 infection might accelerate aging in neurons, focusing on peculiar marks of aged cells, such as the increase in histone H4 lysine (K) 16 acetylation (ac) (H4K16ac); the decrease of H3K56ac, and the modified expression of Sin3/HDAC1 and HIRA proteins. By exploiting both in vitro and in vivo models of recurrent HSV-1 infection, we found a significant increase in H4K16ac, Sin3, and HDAC1 levels, suggesting that the neuronal response to virus latency and reactivation includes the upregulation of these aging markers. On the contrary, we found a significant decrease in H3K56ac that was specifically linked to viral reactivation and apparently not related to aging-related markers. A complex modulation of HIRA expression and localization was found in the brain from HSV-1 infected mice suggesting a specific role of this protein in viral latency and reactivation. Overall, our results pointed out novel molecular mechanisms through which recurrent HSV-1 infection may affect neuronal aging, likely contributing to neurodegeneration.

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