Antiviral and synergistic effects of photo-energy with acyclovir on herpes simplex virus type 1 infection.

This experimental study aimed to evaluate the antiviral and synergistic effects of photoenergy irradiation on human herpes simplex virus type I (HSV-1) infection. We assessed viral replication, plaque formation, and relevant viral gene expression to examine the antiviral and synergistic effects of blue light (BL) with acyclovir treatment. Our results showed that daily BL (10 J/cm2) irradiation inhibited plaque-forming ability and decreased viral copy numbers in HSV-1-infected monkey kidney epithelial Vero cells and primary human oral keratinocyte (HOK) cells. Combined treatment with the antiviral agent acyclovir and BL irradiation increased anti-viral activity, reducing viral titers and copy numbers. In particular, accumulated BL irradiation suppressed characteristic viral genes including UL19 and US6, and viral DNA replication-essential genes including UL9, UL30, UL42, and UL52 in HOK cells. Our results suggest that BL irradiation has anti-viral and synergistic properties, making it a promising therapeutic candidate for suppressing viral infections in clinical trials.

Treatment of herpes labialis by photodynamic therapy: Study protocol clinical trial (SPIRIT compliant).

BACKGROUND: Lesions of herpes labialis are caused by the herpes simplex virus type 1 and cause pain and aesthetic compromise. It is characterized by the formation of small vesicles that coalesce and rupture forming extremely painful ulcers, that evolve to crusts, dry desquamations until their complete remission. Currently the treatment of these lesions is done with acyclovir. Although it diminishes the symptomatology, it causes viral resistance and does not prevent the recurrence of the lesions. It is known that antimicrobial photodynamic therapy (aPDT) has numerous advantages, among them: the reduction of the time of remission, and does not cause resistance. This protocol will determine the effectiveness of PDT in lesions of herpes labialis. MATERIALS AND METHODS: A total of 30 patients with herpes labialis in the prodromal stage of vesicles, ulcers, and crusts will be selected to participate in the study and randomized into 2 groups: G1 control and G2 experimental. After signing Research Ethics Committee and TA, patients in group G1 will undergo the standard gold treatment for herpes labialis with acyclovir and simulated PDT treatment. Patients in the experimental G2 group will be treated simulating the gold standard treatment of herpes labialis (placebo) and PDT. In all patients, saliva samples will be collected for analysis of cytokines, and will be performed exfoliative cytology in the lesions. The pain will be assessed through a pain scale and a questionnaire of quality of life related to oral health (OHIP-14) will be given to them. Patients will continue to be followed up after 7 days, 1 month, 3 months, and 6 months; if there is a recurrence of the lesion, they will contact the researchers.Clinical registration: clinicaltrials.gov - NCT04037475. Registered on July 2019.

UV Light-inactivated HSV-1 Stimulates Natural Killer Cell-induced Killing of Prostate Cancer Cells.

Herein we demonstrate that ultraviolet light-inactivated Herpes Simplex Virus-1 (UV-HSV-1) stimulates peripheral blood mononuclear cells (PBMCs) to lyse both androgen-sensitive and androgen-independent prostate cancer (PrCA) cell lines, but not the benign prostatic hyperplastic epithelial cell line, BPH-1, and is 1000-10,000-fold more potent at stimulating this killing than ultraviolet light-inactivated Vesicular Stomatitis Virus, adenovirus, reovirus or cytomegalovirus. Among PBMCs, natural killer (NK) cells appear to be a major cell type involved in this killing and UV-HSV-1 appears to directly and potently stimulate NK cell expression of CD69, degranulation, cytokine production, and migration to IL-8 in PC3 conditioned medium. We also found that UV-HSV-1 stimulates glycolysis in PBMCs and NK cells, and that 2-deoxyglucose and the protein kinase C inhibitor, Go6976, and the NFκB inhibitor, Bay 11-7082, all abrogate UV-HSV-1 activated killing of PC3 cells by PBMCs and NK cells. Using neutralizing anti-Toll-like receptor 2 (TLR2) we found that UV-HSV-1, like HSV-1, activates NK cells via TLR2. Taken together, these results are consistent with Toll-like receptor 2 ligands on UV-HSV-1 stimulating TLR2 on NK cells to activate protein kinase C, leading to enhanced glycolysis and NFκB activation, both of which play a critical role in this anti-PrCA innate immune response. Importantly, UV-HSV-1 synergizes with IL-15 to increase the cytolytic activity of PBMCs against PC3 cells and there was considerable donor-to-donor variation in killing ability. These results support the preclinical development of UV-HSV-1 as an adjuvant, in combination with IL-15, for cell infusions of healthy, preselected NK cells to treat PrCA.

Classical Type 1 Dendritic Cells Dominate Priming of Th1 Responses to Herpes Simplex Virus Type 1 Skin Infection.

CD4+ T cell responses are crucial for the control of many intracellular pathogens, yet the requirements for their induction are not fully understood. To better understand the role that various dendritic cell (DC) subtypes play in CD4+ T cell priming, we compared in vivo T cell responses to skin inoculation of mice with infectious or UV-inactivated HSV type 1. Localized infection elicited a Th1 response that was primed in skin-draining lymph nodes involving Ag presentation by migratory dermal and lymph node-resident DC. However, expansion and Th1 differentiation was impaired in response to UV-inactivated virus (UV-HSV), and this defect correlated with a restriction of Ag presentation to migratory CD103- dermal DC. A similar differentiation defect was seen in infected mice lacking CD8α+ and CD103+ classical type 1 DC (cDC1). Finally, Th1 differentiation after UV-HSV inoculation was rescued by targeted Ag delivery to CD8α+ and CD103+ cDC1 using an anti-Clec9A Ab construct. This suggests that Ag presentation by cDC1 is crucial for optimal Th1 immunity to HSV type 1 infection and potentially other pathogens of the skin.

Acidic pH Mediates Changes in Antigenic and Oligomeric Conformation of Herpes Simplex Virus gB and Is a Determinant of Cell-Specific Entry.

Herpes simplex virus (HSV) is an important human pathogen with a high worldwide seroprevalence. HSV enters epithelial cells, the primary site of infection, by a low-pH pathway. HSV glycoprotein B (gB) undergoes low pH-induced conformational changes, which are thought to drive membrane fusion. When neutralized back to physiological pH, these changes become reversible. Here, HSV-infected cells were subjected to short pulses of radiolabeling, followed by immunoprecipitation with a panel of gB monoclonal antibodies (MAbs), demonstrating that gB folds and oligomerizes rapidly and cotranslationally in the endoplasmic reticulum. Full-length gB from transfected cells underwent low-pH-triggered changes in oligomeric conformation in the absence of other viral proteins. MAbs to gB neutralized HSV entry into cells regardless of the pH dependence of the entry pathway, suggesting a conservation of gB function in distinct fusion mechanisms. The combination of heat and acidic pH triggered irreversible changes in the antigenic conformation of the gB fusion domain, while changes in the gB oligomer remained reversible. An elevated temperature alone was not sufficient to induce gB conformational change. Together, these results shed light on the conformation and function of the HSV-1 gB oligomer, which serves as part of the core fusion machinery during viral entry.IMPORTANCE Herpes simplex virus (HSV) causes infection of the mouth, skin, eyes, and genitals and establishes lifelong latency in humans. gB is conserved among all herpesviruses. HSV gB undergoes reversible conformational changes following exposure to acidic pH which are thought to mediate fusion and entry into epithelial cells. Here, we identified cotranslational folding and oligomerization of newly synthesized gB. A panel of antibodies to gB blocked both low-pH and pH-neutral entry of HSV, suggesting conserved conformational changes in gB regardless of cell entry route. Changes in HSV gB conformation were not triggered by increased temperature alone, in contrast to results with EBV gB. Acid pH-induced changes in the oligomeric conformation of gB are related but distinct from pH-triggered changes in gB antigenic conformation. These results highlight critical aspects of the class III fusion protein, gB, and inform strategies to block HSV infection at the level of fusion and entry.

Blockade of LAG-3 Immune Checkpoint Combined With Therapeutic Vaccination Restore the Function of Tissue-Resident Anti-viral CD8+ T Cells and Protect Against Recurrent Ocular Herpes Simplex Infection and Disease.

Recurrent viral diseases often occur after the viruses evade the hosts' immune system, by inducing exhaustion of antiviral T cells. In the present study, we found that functionally exhausted herpes simplex virus type 1 (HSV-1) -specific CD8+ T cells, with elevated expression of lymphocyte activation gene-3 (LAG-3), an immune checkpoint receptor that promotes T cell exhaustion, were frequent in symptomatic (SYMP) patients with a history of numerous episodes of recurrent corneal herpetic disease. Similarly, following UV-B induced virus reactivation from latency the symptomatic wild-type (WT) B6 mice that developed increase virus shedding and severe recurrent corneal herpetic disease had more exhausted HSV-specific LAG-3+CD8+ T cells in both trigeminal ganglia (TG) and cornea. Moreover, a therapeutic blockade of LAG-3 immune checkpoint with antagonist antibodies combined with a therapeutic immunization with gB498-505 peptide immunodominant epitope of latently infected B6 mice significantly restored the quality and quantity of functional HSV-1 gB498-505 specific CD8+ T cells in both TG and cornea and protected against UV-B induced recurrent corneal herpes infection and disease. In contrast to dysfunctional HSV-specific CD8+ T cells from WT B6 mice, more functional HSV-specific CD8+ T cells were detected in LAG-3-/- deficient mice and were associated with less UV-B induced recurrent corneal herpetic disease. Thus, the LAG-3 pathway plays a fundamental role in ocular herpes T cell immunopathology and provides an important immune checkpoint target that can synergizes with T cell-based therapeutic vaccines against symptomatic recurrent ocular herpes.

Lack of TNF-α signaling through p55 makes the mice more susceptible to acute infection but does not alter state of latency and reactivation of HSV-1.

TNF-α has been shown to play an important role in pathogenesis and latency of HSV-1 infections. TNF-α signals through TNFR1 (p55) and TNFR2 (p75), and signaling through p55 generally results in gene activation leading to induction of inflammatory responses. Here, we studied the role of TNF-α signaling in latent virus reactivation in p55-knock out (KO) mouse model of ocular HSV-1 infection. We found that KO mice are more susceptible to HSV-1 infection compared to wild type C57Bl/6 mice. While the absence of TNFRI signaling enhanced the ganglion latent DNA content by two folds, there was no difference in the maintenance and reactivation of latent HSV-1. Strikingly, interfering with inflammatory responses through PGE2 synthesis by treating latently infected wild type mice with indomethacin (COX inhibitor) prior to UV-exposure prevented HSV-1 reactivation. These results suggest that reactivation of latent HSV-1 might result from the cumulative effects of a cascade of inflammatory cytokines including TNF-α.

Herpes simplex virus-1 entrapped in Candida albicans biofilm displays decreased sensitivity to antivirals and UVA1 laser treatment.

BACKGROUND: Recently, we published data suggesting a mutualistic relationship between HSV-1 and Candida. albicans; in particular: (a) HSV-1 infected macrophages are inhibited in their anti-Candida effector function and (b) Candida biofilm protects HSV-1 from inactivation. The present in vitro study is aimed at testing the effects of Candida biofilm on HSV-1 sensitivity to pharmacological and physical stress, such as antiviral drugs (acyclovir and foscarnet) and laser UVA1 irradiation. We also investigated whether fungus growth pattern, either sessile or planktonic, influences HSV-1 sensitivity to antivirals. METHODS: Mature Candida biofilms were exposed to HSV-1 and then irradiated with laser light (UVA1, 355 λ). In another set of experiments, mature Candida biofilm were co-cultured with HSV-1 infected VERO cells in the presence of different concentrations of acyclovir or foscarnet. In both protocols, controls unexposed to laser or drugs were included. The viral yield of treated and untreated samples was evaluated by end-point titration. To evaluate whether this protective effect might occur in relation with a different growth pattern, HSV-1 infected cells were co-cultured with either sessile or planktonic forms of Candida and then assessed for susceptibility to antiviral drugs. RESULTS: UVA1 irradiation caused a 2 Log reduction of virus yield in the control cultures whereas the reduction was only 1 Log with Candida biofilm, regardless to the laser dose applied to the experimental samples (50 or 100 J/cm2). The presence of biofilm increased the IC90 from 18.4-25.6 J/cm2. Acyclovir caused a 2.3 Log reduction of virus yield in the control cultures whereas with Candida biofilm the reduction was only 0.5 Log; foscarnet determined a reduction of 1.4 Log in the controls and 0.2 Log in biofilm cultures. Consequently, the ICs50 for acyclovir and foscarnet increased by 4- and 12-folds, respectively, compared to controls. When HSV-1 was exposed to either sessile or planktonic fungal cells, the antiviral treatments caused approximately the same weak reduction of virus yield. CONCLUSIONS: These data demonstrate that: (1) HSV-1 encompassed in Candida biofilm is protected from inactivation by physical (laser) and pharmacological (acyclovir or foscarnet) treatments; (2) the drug antiviral activity is reduced at a similar extent for both sessile or planktonic Candida.

Virus inactivation under the photodynamic effect of phthalocyanine zinc(II) complexes.

Various metal phthalocyanines have been studied for their capacity for photodynamic effects on viruses. Two newly synthesized water-soluble phthalocyanine Zn(II) complexes with different charges, cationic methylpyridyloxy-substituted Zn(II)- phthalocyanine (ZnPcMe) and anionic sulfophenoxy-substituted Zn(II)-phthalocyanine (ZnPcS), were used for photoinactivation of two DNA-containing enveloped viruses (herpes simplex virus type 1 and vaccinia virus), two RNA-containing enveloped viruses (bovine viral diarrhea virus and Newcastle disease virus) and two nude viruses (the enterovirus Coxsackie B1, a RNA-containing virus, and human adenovirus 5, a DNA virus). These two differently charged phthalocyanine complexes showed an identical marked virucidal effect against herpes simplex virus type 1, which was one and the same at an irradiation lasting 5 or 20 min (Δlog=3.0 and 4.0, respectively). Towards vaccinia virus this effect was lower, Δlog=1.8 under the effect of ZnPcMe and 2.0 for ZnPcS. Bovine viral diarrhea virus manifested a moderate sensitivity to ZnPcMe (Δlog=1.8) and a pronounced one to ZnPcS at 5- and 20-min irradiation (Δlog=5.8 and 5.3, respectively). The complexes were unable to inactivate Newcastle disease virus, Coxsackievirus B1 and human adenovirus type 5.

Effectiveness of hydrogen peroxide and electron-beam irradiation treatment for removal and inactivation of viruses in equine-derived xenografts.

Bone grafting is a common procedure for bone reconstruction in dentistry, orthopedics, and neurosurgery. A wide range of grafts are currently used, and xenografts are regarded as an interesting alternative to autogenous bone because all mammals share the same bone mineral component composition and morphology. Antigens must be eliminated from bone grafts derived from animal tissues in order to make them biocompatible. Moreover, the processing method must also safely inactivate and/or remove viruses or other potential infectious agents. This study assessed the efficacy of two steps applied in manufacturing some equine-derived xenografts: hydrogen-peroxide and e-beam sterilization treatments for inactivation and removal of viruses in equine bone granules (cortical and cancellous) and collagen and pericardium membranes. Viruses belonging to three different human viral species (Herpes simplex virus type 1, Coxsackievirus B1, and Influenzavirus type A H1N1) were selected and used to spike semi-processed biomaterials. For each viral species, the tissue culture infective dose (TCID50) on cell lines and the number of genome copies through qPCR were assessed. Both treatments were found to be effective at virus inactivation. Considering the model viruses studied, the application of hydrogen peroxide and e-beam irradiation could also be considered effective for processing bone tissue of human origin.

In vitro studies of the antiherpetic effect of photodynamic therapy.

The number of viral infection cases in the Department of Gynecology and Obstetrics has tended to increase over last few years. Viruses form herpesvirus and cytomegalovirus families are associated with an increased risk for recurrent pregnancy loss. Photodynamic therapy (PDT) is a promising new approach to treat viral infections in which viral particles are inactivated. It exhibits great therapeutic potential, particularly among this group of patients. This study examined the use of PDT to treat herpesvirus infection (HVI) using an in vitro model. In this study, we used the Vero сell lineage as a suitable model of HVI, strains of HSV-1 (strain VR-3) and HSV-2 (strain MS) obtained from The National Virus Collection (London, UK), the photosensitizer Fotoditazine (Veta-Grand, Russia), an AFS physiotherapeutic device (Polironic Corporation, Russia). Laser light irradiation and the photosensitizer had different cytotoxic effects on the Vero cell cultures depending on the doses used. The optimal laser light and photosensitizer doses were determined. PDT had an antiviral effect on an in vitro model of HVI in cell culture. PDT has been shown to be effective treatment for HVI in vitro, leading to a reliable decrease of viral titer.

HSV-1 Infection Modulates the Radioresponse of a HPV16-positive Head and Neck Cancer Cell Line.

BACKGROUND: The combined effects of Human papillomavirus (HPV) and Herpes simplex type 1 (HSV-1) infections and their effects on cancer cell radioresistance are unexplored. MATERIALS AND METHODS: An HPV16-positive hypopharyngeal carcinoma cell line (UD-SCC-2) was infected with wt-HSV-1 at low multiplicity of infection (MOI) and irradiated with 2 Gy at 24 h postinfection. Viability assays and quantitative reverse-transcriptase PCR for HPV16 E6, E7, nuclear factor kappa B1, B-cell CLL/lymphoma 2 (BCL2), and caspases 3, 8 and 9 at 24, and 72 h, as well as immunocytochemistry for BCL2, caspase 3, cyclin E, mouse double minute 2 homolog (MDM2), HSV-1 and Ki-67 were performed at 144 h postirradiation. RESULTS: At 144 h, cell viability was significantly lowered by irradiation only in uninfected cells. Infection combined with irradiation resulted in increased expression of E6, E7, BCL2 and NF-κB1 at 144 h. Simultaneously, E6 and E7 were down-regulated in non-irradiated infected cells. Irradiation and infection with 0.00001 MOI separately up-regulated caspase 3 but infection with 0.0001 MOI halved its expression in irradiated cells. CONCLUSION: HSV-1 infection modulates radioresistance of HPV16-positive hypopharyngeal carcinoma cells.

Prior Corneal Scarification and Injection of Immune Serum are Not Required Before Ocular HSV-1 Infection for UV-B-Induced Virus Reactivation and Recurrent Herpetic Corneal Disease in Latently Infected Mice.

PURPOSE: Blinding ocular herpetic disease in humans is due to spontaneous reactivation of herpes simplex virus type 1 (HSV-1) from latency, rather than to primary acute infection. Mice latently infected with HSV-1 undergo little or no in vivo spontaneous reactivation with accompanying virus shedding in tears. HSV-1 reactivation can be induced in latently infected mice by several in vivo procedures, with UV-B-induced reactivation being one commonly used method. In the UV-B model, corneas are scarified (lightly scratched) just prior to ocular infection to increase efficiency of the primary infection and immune serum containing HSV-1 neutralizing antibodies is injected intraperitoneally (i.p.) to increase survival and decrease acute corneal damage. Since scarification can significantly alter host gene transcription in the cornea and in the trigeminal ganglia (TG; the site of HSV-1 latency) and since injection of immune serum likely modulates innate and adaptive herpes immunity, we investigated eliminating both treatments. MATERIAL AND METHODS: Mice were infected with HSV-1 with or without corneal scarification and immune serum. HSV-1 reactivation and recurrent disease were induced by UV-B irradiation. RESULTS: When corneal scarification and immune serum were both eliminated, UV-B irradiation still induced both HSV-1 reactivation, as measured by shedding of reactivated virus in tears and herpetic eye disease, albeit at reduced levels compared to the original procedure. CONCLUSION: Despite the reduced reactivation and disease, avoidance of both corneal scarification and immune serum should improve the clinical relevance of the UV-B mouse model.

Photo inactivation of virus particles in microfluidic capillary systems.

It has long been established that UVC light is a very effective method for inactivating pathogens in a fluid, yet the application of UVC irradiation to modern biotechnological processes is limited by the intrinsic short penetration distance of UVC light in optically dense protein solutions. This experimental and numerical study establishes that irradiating a fluid flowing continuously in a microfluidic capillary system, in which the diameter of the capillary is tuned to the depth of penetration of UVC light, uniquely treats the whole volume of the fluid to UVC light, resulting in fast and effective inactivation of pathogens, with particular focus to virus particles. This was demonstrated by inactivating human herpes simplex virus type-1 (HSV-1, a large enveloped virus) on a dense 10% fetal calf serum solution in a range of fluoropolymer capillary systems, including a 0.75 mm and 1.50 mm internal diameter capillaries and a high-throughput MicroCapillary Film with mean hydraulic diameter of 206 µm. Up to 99.96% of HSV-1 virus particles were effectively inactivated with a mean exposure time of up to 10 s, with undetectable collateral damage to solution proteins. The kinetics of virus inactivation matched well the results from a new mathematical model that considers the parabolic flow profile in the capillaries, and showed the methodology is fully predictable and scalable and avoids both the side effect of UVC light to proteins and the dilution of the fluid in current tubular UVC inactivation systems. This is expected to speed up the industrial adoption of non-invasive UVC virus inactivation in clinical biotechnology and biomanufacturing of therapeutic molecules. Biotechnol. Bioeng. 2016;113: 1481-1492. © 2015 Wiley Periodicals, Inc.

Efficacy of the ND:YAG laser therapy on EBV and HSV1 contamination in periodontal pockets.

AIM: The aim of this retrospective multicenter study was to verify the efficacy of Nd:YAG laser in the treatment of periodontal pockets infected by Epstein-Barr Virus (EBV) and Herpes Simplex Virus 1 (HSV1). METHODS: Subgingival plaque samples of 291 Italian periodontal patients were analyzed by Real Time PCR to evaluate the frequency of both viruses before and after Nd:YAG laser-assisted periodontal treatment. RESULTS: Before treatment, EBV and HSV1 were observed in 29.9% and in 3.8% of periodontal patients respectively, while co-infection with both viruses was detected in 1.7% of cases. Periodontal Nd:YAG laser treatment ("Periodontal Biological Laser-Assisted Therapy", PERIOBLAST) produced statistical significant benefits, especially in EBV periodontal infection: 78.2% of EBV positive patients became EBV-negative following treatment. CONCLUSIONS: Results of this preliminary study highlight that EBV is found in periodontal pockets more frequently than HSV1, supporting the theory of the potential role of EBV in the onset and progression of periodontal disease. Moreover, our data showed that Nd:YAG laser-assisted periodontal treatment (Perioblast) is also effective in case of viral infection, validating evidences that it represents a successful alternative approach to traditional periodontal protocols.

Entry of Oncolytic Herpes Simplex Virus into Human Squamous Cell Carcinoma Cells by Ultrasound.

Low-intensity ultrasound is a useful method to introduce materials into cells due to the transient formation of micropores, called sonoporations, on the cell membrane. Whether oncolytic herpes simplex virus type 1 (HSV-1) can be introduced into oral squamous cell carcinoma (SCC) cells through membrane pores remains undetermined. Human SCC cell line SAS and oncolytic HSV-1 RH2, which was deficient in the 134.5 gene and fusogenic, were used. Cells were exposed to ultrasound in the presence or absence of microbubbles. The increase of virus entry was estimated by plaque numbers. Viral infection was hardly established without the adsorption step, but plaque number was increased by the exposure of HSV-1-inoculated cells to ultrasound. Plaque number was also increased even if SAS cells were exposed to ultrasound and inoculated with RH2 without the adsorption step. This effect was abolished when the interval from ultrasound exposure to virus inoculation was prolonged. Scanning electron microscopy revealed depressed spots on the cell surface after exposure to ultrasound. These results suggest that oncolytic HSV-1 RH2 can be introduced into SAS cells through ultrasound-mediated pores of the cell membrane that are resealed after an interval.

The rigid amphipathic fusion inhibitor dUY11 acts through photosensitization of viruses.

Rigid amphipathic fusion inhibitors (RAFIs) are lipophilic inverted-cone-shaped molecules thought to antagonize the membrane curvature transitions that occur during virus-cell fusion and are broad-spectrum antivirals against enveloped viruses (Broad-SAVE). Here, we show that RAFIs act like membrane-binding photosensitizers: their antiviral effect is dependent on light and the generation of singlet oxygen ((1)O(2)), similar to the mechanistic paradigm established for LJ001, a chemically unrelated class of Broad-SAVE. Photosensitization of viral membranes is a common mechanism that underlies these Broad-SAVE.

High pressure treatment under subfreezing temperature results in drastic inactivation of enveloped and non-enveloped viruses.

Some viruses are sensitive to high pressure. The freeze-pressure generation method (FPGM) applies pressure as high as 250 MPa on a substance, simply by freezing a pressure-resistant reservoir in which the substance is immersed in water. Here we examined whether the FPGM successfully inactivates herpes simplex virus type 1 (HSV-1), an enveloped DNA virus belonging to the human Herpesviridae, and encephalomyocarditis virus (EMCV), an envelope-free RNA virus belonging to the Picornaviridae. After the treatment, HSV-1 drastically reduced the ability to form plaque in Vero cells in vitro as well as to kill mice in vivo. EMCV that had been pressurized failed to proliferate in HeLa cells and induce interferon response. The results suggest that the FPGM provides a feasible procedure to inactivate a broad spectrum of viruses.

Increased oncolytic efficacy for high-grade gliomas by optimal integration of ionizing radiation into the replicative cycle of HSV-1.

Oncolytic viruses have been combined with standard cancer therapies to increase therapeutic efficacy. Given the sequential activation of herpes viral genes (herpes simplex virus-1, HSV-1) and the temporal cellular changes induced by ionizing radiation, we hypothesized an optimal temporal sequence existed in combining oncolytic HSV-1 with ionizing radiation. Murine U-87 glioma xenografts were injected with luciferase encoding HSV-1, and ionizing radiation (IR) was given at times before or after viral injection. HSV-1 replication and tumor-volume response were followed. Radiation given 6-9 h after HSV-1 injection resulted in maximal viral luciferase expression and infectious viral production in tumor xenografts. The greatest xenograft regression was also seen with radiation given 6 h after viral injection. We then tested if HSV-1 replication had a dose response to ionizing radiation. HSV-1 luciferase expression exhibited a dose response as xenografts were irradiated from 0 to 5 Gy. There was no difference in viral luciferase expression as IR dose increased from 5 Gy up to 20 Gy. These results suggest that the interaction of IR with the HSV-1 lytic cycle can be manipulated for therapeutic gain by delivering IR at a specific time within viral replicative cycle.

Inhibition of HSV-1 replication by laser diode-irradiation: possible mechanism of action.

Herpes labialis are the most frequent clinical manifestations of HSV-1 infection. Epithelial cells are able to respond to HSV-1 presence inducing the expression of IL-6, IL-1, TNF-α and IL-8. These proinflammatory cytokines have a function in the acute-phase response mediation, chemotaxis, inflammatory cell activation and antigen-presenting cells. In the human epithelial cell models, it has been demonstrated that, after an early induction of proinflammatory host response, HSV-1 down-modulates the proinflammatory cytokine production through the accumulation of two viral proteins, ICP4 and ICP27, whose transcription is induced by tegument protein VP16. These viral proteins, through the decreasing of stabilizing the mRNAs of proinflammatory genes, delay cytokine production to an extent that allows the virus to replicate. Moreover, viral transactivating proteins, ICP-0 and VP-16 induce IL-10 expression. The conventional treatment of herpes labialis involves the topical and systemic use of antiviral drugs but it is necessary to find new therapies that can act in a selective and non-cytotoxic manner in viral infection. Laser diode therapy has been considered as a non-invasive alternative treatment to the conventional treatment of herpes labialis in pain therapy, in modulation of inflammation and in wound healing. This study aims to report a possible mechanism of action of laser diode irradiation in prevention and reduction of severity of labial manifestations of herpes labialis virus. We investigated, in an in vitro model of epithelial cells HaCat, the laser-effect on HSV-1 replication and we evaluated the modulation of expression of certain proinflammatory cytokines (TNF-α, IL-1ß and IL-6), antimicrobial peptide HBD2, chemokine IL-8 and the immunosuppressive cytokine, IL-10. Our results lead us to hypothesize that LD-irradiation acts in the final stage of HSV-1 replication by limiting viral spread from cell to cell and that laser therapy acts also on the host immune response unblocking the suppression of proinflammatory mediators induced by accumulation of progeny virus in infected epithelial cells.