Inactivation Of Herpes Simplex Virus Research Articles

Instantaneous Inactivation of Herpes Simplex Virus by Silicon Nitride Bioceramics.

Hydrolytic reactions taking place at the surface of a silicon nitride (Si3N4) bioceramic were found to induce instantaneous inactivation of Human herpesvirus 1 (HHV-1, also known as Herpes simplex virus 1 or HSV-1). Si3N4 is a non-oxide ceramic compound with strong antibacterial and antiviral properties that has been proven safe for human cells. HSV-1 is a double-stranded DNA virus that infects a variety of host tissues through a lytic and latent cycle. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) tests of HSV-1 DNA after instantaneous contact with Si3N4 showed that ammonia and its nitrogen radical byproducts, produced upon Si3N4 hydrolysis, directly reacted with viral proteins and fragmented the virus DNA, irreversibly damaging its structure. A comparison carried out upon testing HSV-1 against ZrO2 particles under identical experimental conditions showed a significantly weaker (but not null) antiviral effect, which was attributed to oxygen radical influence. The results of this study extend the effectiveness of Si3N4's antiviral properties beyond their previously proven efficacy against a large variety of single-stranded enveloped and non-enveloped RNA viruses. Possible applications include the development of antiviral creams or gels and oral rinses to exploit an extremely efficient, localized, and instantaneous viral reduction by means of a safe and more effective alternative to conventional antiviral creams. Upon incorporating a minor fraction of micrometric Si3N4 particles into polymeric matrices, antiherpetic devices could be fabricated, which would effectively impede viral reactivation and enable high local effectiveness for extended periods of time.

Inactivation of Herpes Simplex Virus by Photosensitizing Anthraquinones Isolated from Heterophyllaea pustulata.

Heterophyllaea pustulata is a phototoxic plant from Argentina. Aerial parts extracts, high in photosensitizing anthraquinones, have shown in vitro antiviral activity. The purpose of this study was to study the antiherpetic activity of the main purified anthraquinones, even evaluating their competence as photodynamic sensitizers to photo-stimulate the antiviral effect. In vitro antiviral activity against Herpes Simplex virus type I and the photo-inactivation of viral particle were studied by the Neutral Red uptake test and observation of the cytopathic effect. Rubiadin 1-methyl ether and 5,5'-bisoranjidiol produced a significant effect (≥ 80% inhibition) with minimal damage to host cells (subtoxic concentration). Anthraquinones with poor antiherpetic activity at its maximum noncytotoxic concentration showed an important photo-stimulated effect, such is the case of soranjidiol and 5,5'-bisoranjidiol (28.0 ± 6.3 vs. 81.8 ± 2.1% and 15.5 ± 0.3 vs. 89.8 ± 1.7%, respectively). The study also proved the decrease of viral particles, necessary to reduce infection. Therefore, photosensitizing anthraquinones from natural resources could be proposed to develop new treatments for localized viral lesions with antimicrobial photodynamic therapy.

Photodynamic Inactivation of Herpes Simplex Viruses.

Herpes simplex virus (HSV) infections can be treated with direct acting antivirals like acyclovir and foscarnet, but long-term use can lead to drug resistance, which motivates research into broadly-acting antivirals that can provide a greater genetic barrier to resistance. Photodynamic inactivation (PDI) employs a photosensitizer, light, and oxygen to create a local burst of reactive oxygen species that inactivate microorganisms. The botanical plant extract OrthoquinTM is a powerful photosensitizer with antimicrobial properties. Here we report that Orthoquin also has antiviral properties. Photoactivated Orthoquin inhibited herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) infection of target cells in a dose-dependent manner across a broad range of sub-cytotoxic concentrations. HSV inactivation required direct contact between Orthoquin and the inoculum, whereas pre-treatment of target cells had no effect. Orthoquin did not cause appreciable damage to viral capsids or premature release of viral genomes, as measured by qPCR for the HSV-1 genome. By contrast, immunoblotting for HSV-1 antigens in purified virion preparations suggested that higher doses of Orthoquin had a physical impact on certain HSV-1 proteins that altered protein mobility or antigen detection. Orthoquin PDI also inhibited the non-enveloped adenovirus (AdV) in a dose-dependent manner, whereas Orthoquin-mediated inhibition of the enveloped vesicular stomatitis virus (VSV) was light-independent. Together, these findings suggest that the broad antiviral effects of Orthoquin-mediated PDI may stem from damage to viral attachment proteins.

Mutational Inactivation of Herpes Simplex Virus 1 MicroRNAs Identifies Viral mRNA Targets and Reveals Phenotypic Effects in Culture

Herpes simplex virus 1 (HSV-1), a ubiquitous human pathogen, expresses several viral microRNAs (miRNAs). These, along with the latency-associated transcript, represent the only viral RNAs detectable in latently infected neuronal cells. Here, for the first time, we analyze which HSV-1 miRNAs are loaded into the RNA-induced silencing complex (RISC), the key effector of miRNA function. Only 9 of the 17 reported HSV-1 miRNAs, i.e., miR-H1 to miR-H8 plus miR-H11, were found to actually load into the RISC. Surprisingly, this analysis also revealed that HSV-1 miRNAs loaded into the RISC with efficiencies that differed widely; <1% of the miR-H1-3p miRNA detectable in HSV-1-infected cells was loaded into the RISC. Analysis of HSV-1 mutants individually lacking the viral miR-H2, miR-H3, or miR-H4 miRNA revealed that loss of these miRNAs affected the rate of replication of HSV-1 in neuronal cells but not in fibroblasts. Analysis of mRNA and protein expression, as well as assays mapping viral miRNA binding sites in infected cells, showed that endogenous HSV-1 miR-H2 binds to viral ICP0 mRNA and inhibits its expression, while endogenous miR-H4 inhibits the expression of the viral ICP34.5 gene. In contrast, no viral mRNA target for miR-H3 could be detected, even though miR-H3, like miR-H4, is perfectly complementary to ICP34.5 mRNA. Together, these data demonstrate that endogenous HSV-1 miRNA expression can significantly alter viral replication in culture, and they also identify two viral mRNA targets for miR-H2 and miR-H4 that can partially explain this phenotype.

Co-operative thermal inactivation of herpes simplex virus and influenza virus by arginine and NaCl

Elevated temperatures have been used to inactivate viruses for plasma-derived biopharmaceuticals. This paper describes the effects of arginine and NaCl in conjunction with elevated temperature for inactivation of two enveloped viruses, i.e., herpes simplex virus type 1 (HSV-1) and influenza virus type A at neutral pH. In phosphate-buffered saline, a significant inactivation of HSV-1 occurred above 40 °C, resulting in less than 10% surviving virus (over 90% virus inactivation) at 50 °C. Arginine concentration dependently decreased the temperature required for virus inactivation, leading to temperature shift by almost 17 °C at 1.2 M. NaCl also decreased the inactivation temperature, but to a considerably lesser extent, indicating that virus inactivation effect of arginine is not simply due to ionic strength. Influenza virus was also inactivated by high temperature, but its responses to arginine and NaCl were different from those on HSV-1, suggesting that virus inactivation mechanism is different between these two viruses, i.e., the effects of these reagents are virus specific.

319. Inactivation of Herpes Simplex Viruses Following the Manufacturing of Recombinant Adeno-Associated Virus Vector by the Herpes Simplex Virus Co-Infection Method

319. Inactivation of Herpes Simplex Viruses Following the Manufacturing of Recombinant Adeno-Associated Virus Vector by the Herpes Simplex Virus Co-Infection Method

The effect of blood on the antiviral activity of sodium hypochlorite, a phenolic, and a quaternary ammonium compound.

To assess the virucidal activity of three disinfectants (sodium hypochlorite, a phenolic, and a quaternary ammonium compound) in the presence and absence of blood. Disinfectants at varying concentrations (hypochlorite: 5,000, 500, or 50 ppm; phenolic: 1:10 or 1:128 dilution; quaternary ammonium compound: 1:10 or 1:128 dilution) were added to either saline or whole blood (final concentration, 80% or 20% blood) and mixed. Test organisms included an attenuated vaccine strain of poliovirus type 1 (prototype for relatively resistant hydrophilic viruses) and herpes simplex virus (HSV) type 1 (prototype for relatively susceptible lipophilic viruses). Virus was added to create a viral-blood suspension. Viral survival was tested at room temperature at the following times: 0, 15 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, and 10 minutes. A neutralizer stopped the reaction, and virus was assayed using a plaque technique. In the absence of blood, complete inactivation of HSV was achieved within 30 seconds with 5,000 (1:10 dilution of bleach) and 500 (1:100 dilution of bleach) ppm chlorine, 1:10 and 1:128 diluted phenolic (use dilution), and 1:10 and 1:128 diluted quaternary ammonium compound (use dilution). In the presence of 80% blood, only 5,000 ppm hypochlorite, 1:10 phenolic, and 1:10 or 1:128 quaternary ammonium compound were effective. In the absence of blood, complete inactivation of polio was achieved within 30 seconds by 5,000 and 500 ppm chlorine and 1:10 quaternary ammonium compound. In the presence of 80% blood, no solution tested was capable of completely inactivating poliovirus within 10 minutes. Our data suggest that, in the absence of visible blood, environmental surfaces may be disinfected with a diluted hypochlorite solution (1:10 or 1:100), a phenolic, or a quaternary ammonium compound. Based on our studies using HSV, which has similar susceptibilities to disinfectants as human immunodeficiency virus (HIV), phenolics at their use dilution and 1:100 diluted hypochlorite are unlikely to inactivate HIV or hepatitis B virus reliably in the presence of blood. Hypochlorite at a final concentration of 5,000 ppm (1:10 dilution) should be used to decontaminate blood spills, but, even after decontamination, care should be used to avoid sharps injuries.

In vitro inactivation of herpes simplex virus by a biological response modifier, PSK

Herpes simplex virus (HSV) causes herpes genitalis, primary gingivostomatitis and recurrent herpes labialis. In order to elucidate in vivo mechanisms by which PSK, a biological response modifier, exerts a protective effect against HSV infection, we used an in vitro system to study whether PSK inactivated infectivity of HSV-type 1 (HSV-1) and HSV-type 2 (HSV-2) isolated from patients with herpes genitalis in addition to a laboratory-cultured strain of HSV type 1 (HSV-1-GC +). It was found that HSV-1-GC + was inactivated by PSK in a dose dependent fashion of concentrations of PSK and virus titers. Concentrations of PSK as low as 0.31 mg/ml was shown to inactivate the infectivity of HSV-1-GC +. Inactivation required at least 30 min of incubation at 37°C with maximal inactivation observed at 60 min incubation time. Similar to HSV-1-GC +, clinically isolated strains of HSV-2 were inactivated by PSK although clinically isolated strains of HSV-1 were resistant to PSK, compared with HSV-2. It was also shown that PSK-treated HSV retained the ability to adsorb to the cell membrane, but did not synthesize viral protein(s). These data illustrate that there is a biological difference in the sensitivity to PSK between HSV type 1 and type 2, and also suggest that PSK could inactivate HSV in lesions at peripheral sites of recurrent herpes.

Mechanism of copper-mediated inactivation of herpes simplex virus

The inactivation of herpes simplex virus (HSV) by copper was enhanced by the following reducing agents at the indicated relative level: ascorbic acid >> hydrogen peroxide > cysteine. Treatment of HSV-infected cells with combinations of Cu(II) and ascorbate completely inhibited virus plaque formation to below 0.006% of the infectious virus input, while it maintained 30% viability for the host mammalian cells. The logarithm of the surviving fraction of HSV mediated by 1 mg of Cu(II) per liter and 100 mg of reducing agent per liter followed a linear relationship with the reaction time, in which the kinetic rate constant for each reducing agent was -0.87 min(-1) (r = 0.93) for ascorbate, -0.10 min(-1) (r = 0.97) for hydrogen peroxide, and -0.04 min(-1) (r = 0.97) for cysteine. The protective effects of metal chelators and catalase, the lack of effect of superoxide dismutase, and the partial protection conferred by free-radical scavengers suggest that the mechanism of copper-mediated HSV inactivation is similar to that previously reported for copper-mediated DNA damage. The sensitivity exhibited by HSV to Cu(II) and reducing agents, particularly ascorbate, might be useful in the development of therapeutic antiviral agents.

Advances in photochemical approaches for blood sterilization.

Advances in photochemical approaches for blood sterilization.

Suppressive Effect of -9-Tetrahydrocannabinol on Herpes Simplex Virus Infectivity In Vitro

Delta-9-Tetrahydrocannabinol (THC) was found to reduce the infectivity of herpes simplex virus and was without effect against adenovirus type 2 or poliovirus. The effective THC concentration resulting in an 80% decrement in virus viability was dependent upon the presence or absence of serum in the incubation mixture, as a 5% serum concentration decreased the drug activity by approximately 50-fold. THC-mediated inactivation of herpes simplex virus was both time and dose dependent and did not result in virion disassembly or clumping. The THC-related effect was not influenced by the pH of the suspending medium, suggesting that the mechanism of inactivation differed from that associated with the thermal inactivation of the virus. Thus, the data suggest that THC preferentially reduces the infectivity of the enveloped herpes simplex virus, and that this activity is modulated by the presence of serum proteins.

Inactivation of herpes simplex virus by protein components of bovine neutrophil granules

From an acid extract of granules of bovine neutrophils we isolated fractions of cationic proteins, exhibiting significant anti-herpesvirus activity at concentrations which were devoid of cytotoxicity and of activity against a picornavirus (rhinovirus). The mechanism of action seems to involve a direct neutralization of the virions. Two antiviral peptides with an approximate MW 7500 were purified to homogeneity by reversed phase high-performance liquid chromatography. Proline and arginine accounted for about 43% and 26–27% of their amino acid residues. One of these peptides (IIIa 2β) had an MIC of 2 μM.

Porphyrin photosensitization and phototherapy.

Porphyrin photosensitization and phototherapy.

The inactivation of herpes simplex virus by some Solanaceae glycoalkaloids

The infectivity of herpes simplex virus Type I in tissue culture was inhibited by prior incubation with aqueous suspensions of glycoalkaloids in order of activity α-chaconine > α-tomatine > α-solasonine but not by the corresponding aglycones, solanidine, tomatidine and solasodine. However, inhibition was not only dependent on the presence of a sugar moiety since the glycone α-solanine was inactive under the conditions used. The glycones, but not the aglycones, showed cytopathic effects on cellular membranes of Vero cells and erythrocytes; therefore, it is suggested that inactivation of virus results from insertion of the glycones into the viral envelope.

Cryosurvival and inactivation of herpes simplex virus 2 during cryopreservation of human semen

Cryosurvival and inactivation of herpes simplex virus 2 during cryopreservation of human semen

Thermal-pH inactivation of herpes simplex virus: interdependence of the medium composition and the pH on the rate of virus inactivation. Brief report.

The composition and pH of the suspending medium were shown to be interdependent effectors of the in vitro thermal inactivation of herpes simplex virus (HSV). In addition, enhanced thermal sensitivity of HSV at alkaline pH was a medium dependent effect and, therefore, is not an inherent property of the virus.

Inactivation of herpes simplex virus by a pregnene derivative (TX 3047).

1. Two strains of independently purified Herpes simplex virus type 1 were irreversibly inactivated after incubation with the pregnene derivative methyl-p-toluene sulphonate of diethylamino-3-beta-ethoxy-20-hydroxy-pregn-5-ene (TX 3047) in vitro. 2. RNA and DNA synthesis (both cellular and viral) were studied in the presence of TX 3047. Viral and cellular DNA synthesis but not viral RNA synthesis was reduced. 3. Formation of infectious particles was not affected by TX 3047 if the parental virus was absorbed to the cell before it was incubated with TX 3047. This suggests that TX 3047 acts at the level of the membrane.

Herpes virus inactivation by chemical carcinogens: differential inactivation of herpes simplex viruses by 4-nitroquinoline 1-oxide and related compounds.

Treatment of stocks of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) with the chemical carcinogen 4-nitroquinoline 1-oxide (NQO) resulted in inactivation of virus infectivity at rates which were directly dependent on the concentration of NQO and interval of exposure to NQO. HSV-1 strains were more sensitive than HSV-2 strains to inactivation by NQO, although survival curves of both HSV types were multicomponent. Exposure of HSV-2 to a related group of chemicals suggested that the structural specificity required for inactivation of this virus was similar to that established by previous in vivo carcinogenicity tests.

Physical integrity of herpes simplex virus following thermal inactivation.

The effect of thermal inactivation on the gross physical integrity of herpes simplex virus (HSV) was investigated. Purified preparations of HSV containing 3H-thymidine were subjected to thermal inactivation at 36 degrees C, ph 6.3 and pH 7.8 and then were analysed by sucrose gradient centrifugation. The data indicated that although HSV inactivation at 36 degrees C was significantly greater at pH 7.8 than at 6.3, the gross physical integrity of most of the HSV in both of these inactivated virus populations was maintained. In addition, heat inactivated HSV adsorbed to mammalian cells as readily as non-inactivated HSV. Thus, thermal inactivation of HSV does not result in the physical disassembly of the virion particles or in the destruction of virus receptor activity.

Photodynamic inactivation of herpes simplex virus by hematoporphyrin derivative and light.

SummaryA modification of photodynamic inactivation of herpes simplex viruses (HSV) has been developed employing hematoporphyrin derivative (HPD) and visible light. Isolates of HSV Type 1 rapidly and completely lose their plaqueforming ability when a mixture of virus and HPD is exposed to light. This effect is dependent upon optimal concentrations of the tetrapyrrole, light intensity, and the presence of molecular oxygen. Photodynamically inactivated virions do not cause viral cytopathic effects following infection of susceptible cells, and fail to induce viral antigens. The treated particles are unable to adsorb to or penetrate cells, and therefore cannot initiate an infection. These observations are consistent with photooxidative damage to the viral envelope occurring through the interaction of HPD plus light.The expert technical assistance of Ms. Sherie Gibson is gratefully acknowledged. This work was supported in part by a grant from the Milton Fund, and Public Health Service Grant AM-05391. C.S.C. is ...