Herpes Simplex Virus Therapy Research Articles

Neonatal Fever in the Term Infant: Evaluation and Management Strategies

The presence of fever in the neonatal period demands urgent evaluation from healthcare providers since signs and symptoms of a serious bacterial infection in this age group can be nonspecific. Current practice guidelines recommend that febrile neonates should be presumed to have a serious bacterial infection and undergo a sepsis evaluation and hospitalization until the results of diagnostic testing are known. However, less than 50% of outpatient practitioners in a recent study followed these recommendations without apparent adverse outcomes even though the rate of serious bacterial infections in the neonatal period is higher than febrile infants 1-3 months of age. In this article we examine various clinical scenarios that healthcare providers confront when caring for febrile neonates, including whether febrile neonates with respiratory syncytial virus are at increased risk for developing a serious bacterial infection and whether diagnostic testing and empiric antiviral therapy for herpes simplex virus should be part of the standard evaluation of febrile neonates. Although the discovery of inflammatory mediators that are elevated during the early stages of infection has the potential to improve diagnostic capabilities in this age group, there is enough evidence to support international guidelines recommending hospitalization and sepsis evaluations in febrile neonates.

Single-day treatment for orolabial and genital herpes: a brief review of pathogenesis and pharmacology

Herpes simplex virus (HSV) infection is a highly prevalent condition responsible for significant morbidity and occasional mortality each year. Approximately half of all patients infected by HSV will experience at least one recurrence in their lifetime. For these recurrences, traditional therapy has included both suppressive and episodic treatment with nucleoside analogs. In regards to episodic treatment, 2- to 5-day oral regimens are best studied and most commonly reported. As with any medical condition having a well-understood mechanism of action and targeted treatment, therapeutic intervention is only as effective as allowed by patient compliance. Based on these concerns, recent studies have focused on shorter, less complicated, and more affordable options. This review delineates the evidence for single-day treatments of orolabial and genital herpes. Randomized, double-blind studies of both valacyclovir and famciclovir as single-day episodic therapy for HSV have been reported in the literature. Although no head-to-head studies between the drugs have been performed, both regimens produced significant improvement in healing time and symptom resolution over placebo. Single-day therapy for HSV infection is appealing for multiple reasons. First, it simplifies the regimen, increasing likelihood of patient compliance. Additionally, it allows complete delivery of the medication at the onset of symptoms, when viral replication is highest and intervention has greatest effect. Lastly, the reduced number of pills necessary for single versus multiple day therapy decreases the overall cost of treatment per episode, an important factor in modern-day healthcare.

Oncolytic herpes simplex virus therapy for peripheral nerve tumors

Oncolytic viruses are one of many emerging cancer therapies. The surgical management of peripheral nerve tumors carries an inherent risk of damaging the nerves involved and so the search for novel therapies with reduced risk of morbidity continues. In this review the authors discuss the use of oncolytic herpes simplex virus (HSV) in the treatment of peripheral nerve tumors. Herpes simplex virus has a number of characteristics that make it a useful oncolytic vector, including its large, sequenced genome that can accommodate multiple transgenes, its lack of insertional mutagenesis, its ability to infect a wide array of cell types in various species, and the availability of well-established antiviral therapies to treat it. The efficacy of oncolytic HSV therapy against schwannomas and malignant peripheral nerve sheath tumors has been studied in multiple experimental models both in vitro and in vivo. The virus utilizes cell pathways unique to tumors to enhance its oncolytic efficacy, preferentially and effectively targeting and destroying peripheral nerve tumor cells without harming normal cells. This effect is augmented by transgenes expressing antiangiogenic factors, such as dominant-negative fibroblast growth factor receptor and platelet factor 4, and displays synergy with chemotherapy. Different oncolytic HSV vectors have been tested, including hrR3, G207, and G47D. In addition, new animal models have been developed to test the efficacy of oncolytic HSV therapy in peripheral nerve tumors. The safety of oncolytic HSV is well established and has been tested in nonhuman primates and in human clinical trials.

Delayed but Not Early Glucocorticoid Treatment Protects the Host during Experimental Herpes Simplex Virus Encephalitis in Mice

Glucocorticoids (GCs) have not been established as an evidence-based therapy for herpes simplex virus (HSV) encephalitis. We sought to evaluate the effects of early versus delayed GC administration in a model of HSV-1 encephalitis. Mice were inoculated intranasally with a clinical HSV-1 strain and had access to corticosterone (Cort; 0.2 mg/mL) in drinking water or received dexamethasone (DEX; 10 mg/kg) intraperitoneally. Cort was started immediately or 72 h after infection, whereas DEX was administrated 3 days after infection. Expression of the thymidine kinase transcript indicated widespread viral replication in the brain stem and many regions of the mediovestibular system. This neurovirulence provoked neuronal death and transcriptional activation of several immune genes. Notably, Toll-like receptors 2, 3, and 9 transcripts were strongly up-regulated. Mean life expectancy was higher in the group of mice that received delayed Cort (56%) than in the mice that received no Cort (44%) or early Cort treatments (13%) (P<.05, early vs. delayed or no Cort treatments). Delayed DEX treatment suppressed not only the expression of inflammatory genes as expected but also that of viral genes. Administration of GCs at a critical time during viral infection is associated with neuroprotection and survival in experimental HSV-1 encephalitis.

Angiogenic Response Caused by Oncolytic Herpes Simplex Virus–Induced Reduced Thrombospondin Expression Can Be Prevented by Specific Viral Mutations or by Administering a Thrombospondin-Derived Peptide

Wild-type (WT) herpes simplex virus (HSV) causes some pathology, such as ocular keratitis, by increasing infected tissue vascularity, possibly reflecting altered angiogenic factor expression in infected cells. Oncolytic HSVs possess specific mutations enabling selective replication in tumor cells. We investigated whether this ability to enhance infected tissue vascularity is retained in oncolytic HSV, which could be an undesirable effect of oncolytic HSVs that may need to be addressed when treating tumors with oncolytic HSVs. s.c. tumors derived from U87 human glioma cells in athymic mice were treated with oncolytic HSVs G207 or G47Delta in the presence or absence of a recombinant protein composed of the three type-1 repeats (3TSR) of thrombospondin-1 (TSP-1). Real-time reverse transcription-PCR and Western blot of infected cultured cells measured angiogenic factor expression. Microvessel density was assessed using immunofluorescence. G207-treated U87 s.c. tumors had elevated microvessel densities compared with saline- and G47Delta-treated tumors, and G207 treatment caused delayed tumor growth resumption. G207-infected U87 and U373 cells exhibited reduced protein, not mRNA, expression of angiogenesis inhibitors TSP-1 and thrombospondin-2 (TSP-2). 3TSR restored the G207-treated tumor microvessel density to the low level of G47Delta-treated tumors and prevented delayed growth resumption. Oncolytic HSV G207 thus retains the ability of WT HSV to increase infected tissue vascularity. In infected tumors, this increased vascularity is mediated by reduced TSP-1 and TSP-2 levels and causes delayed tumor growth resumption. Incorporating viral mutations, such as those seen in G47Delta or administering thrombospondin-derived peptides, counteracts the angiogenic effect of oncolytic HSV and should be considered when designing oncolytic HSV therapies.

Radiation-Induced Cellular DNA Damage Repair Response Enhances Viral Gene Therapy Efficacy in the Treatment of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) treated with radiotherapy (RT) has incomplete responses as a result of radiation-induced tumoral stress response that repairs DNA damage. Such stress response is beneficial for oncolytic viral therapy. We hypothesized that a combination of RT and NV1066, an oncolytic herpes virus, might exert an additive or synergistic effect in the treatment of MPM. JMN, a MPM cell line, was infected with NV1066 at multiplicities of infection of .05 to .25 in vitro with and without radiation (1 to 5 Gy). Virus replication was determined by plaque assay, cell kill by lactate dehydrogenase assay, and GADD34 (growth arrest and DNA damage repair 34, a DNA damage-repair protein) by real-time reverse transcriptase-polymerase chain reaction and Western blot test. Synergistic cytotoxicity dependence on GADD34 upregulation was confirmed by GADD34 small inhibitory RNA (siRNA). Synergism was demonstrated between RT and NV1066 across a wide range of doses. As a result of such synergism, a dose-reduction for each agent (up to 5500-fold) can be accomplished over a wide range of therapeutic-effect levels without sacrificing tumor cell kill. This effect is correlated with increased GADD34 expression and inhibited by transfection of siRNA directed against GADD34. RT can be combined with oncolytic herpes simplex virus therapy in the treatment of malignant pleural mesothelioma to achieve synergistic efficacy while minimizing dosage and toxicity.

Unusual Case of Acanthamoeba Keratitis in a Contact Lens Wearer

To present an atypical case of acanthamoeba keratitis in a soft contact lens wearer. A case report of a 28-year-old female soft contact lens wearer with a 6-day history of redness and blurred vision in her right eye. Examination showed stromal keratitis that did not respond to therapy for herpes simplex virus. Four weeks later, the patient had increased stromal infiltration, an endothelial plaque, and a hypopyon. She did not complain of pain apart from mild discomfort. Corneal smears and anterior chamber tap were negative for bacteria, fungi, acanthamoeba, and herpes simplex virus, and the patient was prescribed fortified antibiotics. One week later, a large epithelial defect with a surrounding ring infiltrate was apparent. Corneal biopsy showed acanthamoeba. The acanthamoeba keratitis resolved with successful treatment. One year later, the patient had a residual visual deficit secondary to stromal scarring and her best-corrected visual acuity was 20/29. This case emphasizes the importance of considering acanthamoeba species in the differential diagnosis of keratitis, even without the classic symptom of severe pain. A high degree of suspicion with rapid and appropriate treatment may result in improved recovery of vision.

Use of Positron Emission Tomography to Target Prostate Cancer Gene Therapy by Oncolytic Herpes Simplex Virus

Herpes simplex virus (HSV) oncolytic gene therapy is a promising treatment modality against cancer. We have demonstrated that androgen-induced cellular changes enhance oncolytic viral replication and improve efficacy in the treatment of androgen-dependent prostate cancer cell line. Imaging of changes in 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) uptake by positron emission tomography (PET) is a sensitive method of detecting altered cellular metabolism involved in cancer therapy. We therefore hypothesized that FDG-PET can predict tumor response to oncolytic HSV therapy. In this study, androgen increased cell kill (74%) in vitro and enhanced viral yield (2.4-fold) in vivo following HSV therapy. This enhanced efficacy was predicted by high FDG accumulation in intact animals compared to low FDG uptake following orchiectomy (p = 0.002). This proof-of-concept study provides the mechanistic basis for selecting patients for targeted oncolytic viral therapy by means of a noninvasive molecular imaging method in the treatment of prostate cancer.

Radiation Therapy Potentiates Effective Oncolytic Viral Therapy in the Treatment of Lung Cancer

Replication-competent oncolytic herpes simplex viruses with deletion of the gamma(1)34.5 gene preferentially replicate in and kill malignant cells. The gamma(1)34.5 gene codes for ICP 34.5, a protein that enhances viral replication, and is homologous to growth arrest and DNA damage protein 34 (GADD34), a radiation-inducible DNA repair gene. We hypothesized that radiation therapy may potentiate efficacy of oncolytic viral therapy by upregulating GADD34 and promoting viral replication. The A549 and H1299 lung cancer cell lines were infected with NV1066, an oncolytic herpes simplex virus, at multiplicities of infection (number of viral particles per tumor cell) of 0.1 to 0.5 in vitro with radiation (2 to 10 Gy) or without radiation. Viral replication was determined by plaque assay, cell-to-cell spread was determined by flow cytometry, cell kill was determined by lactate dehydrogenase assay, and GADD34 induction was determined by real-time reverse transcription-polymerase chain reaction and Western blot method. Evidence of synergistic cytotoxicity dependence with GADD34 induction is further confirmed by small inhibitory RNA inhibition of GADD34 expression. Using both the isobologram method and combination index method of Chou and Talalay, significant synergism was demonstrated between radiation therapy and NV1066 both in vitro and in vivo. As a result of such synergism, a dose reduction for each agent (2- to 6,000-fold) can be accomplished for a wide range of therapeutic effect levels without sacrificing tumor cell kill. This effect is correlated with increased GADD34 expression and inhibited by transfection of small inhibitory RNA directed against GADD34. These data provide the cellular basis for the clinical investigation of combined use of radiation therapy with oncolytic herpes simplex virus therapy in the treatment of lung cancer to achieve synergistic efficacy while minimizing dosage and toxicity.

160. Systemic Oncolytic Herpes Simplex Virus Therapy of Spontaneously Arising Prostate Cancer in Transgenic TRAMP Mice

Replication competent oncolytic herpes simplex viruses (HSV) are effective agents against a wide spectrum of cancers, including prostate cancer. We have previously evaluated the efficacy of NV1023, a second-generation oncolytic herpes viral mutant of NV1020 for prostate cancer, using the poorly immunogenic TRAMP-C2 tumor model. NV1020, which was recently tested for safety in phase I clinical trial for metastatic liver cancer, contains deletions of one copy of g34.5 and the internal repeat, UL24 and UL56 genes, with addition of gJ, gG, US2 and US3 from HSV-2. NV1023 also has an insertion of LacZ and deletion of the ICP47 and US11 genes. TRAMP-C2 cells are derived from a spontaneously arising prostate adenocarcinoma in TRAMP mouse, in which the SV40 T antigen is under the control of the rat probasin promoter, thus restricting its expression to the epithelial cells of the prostrate. NV1023 was effective when administered intraneoplastically against subcutaneous TRAMP-C2 tumors and when administered intravenously against subcutaneous and metastatic lung TRAMP-C2 tumors.

Neoadjuvant treatment of hepatic malignancy: an oncolytic herpes simplex virus expressing IL-12 effectively treats the parent tumor and protects against recurrence-after resection.

The objective of the study was to evaluate the utility of NV1042, a replication competent, oncolytic herpes simplex virus (HSV) containing the interleukin-12 (IL-12) gene, as primary treatment for hepatic tumors and to further assess its ability to reduce tumor recurrence following resection. Resection is the most effective therapy for hepatic malignancies, but is not possible in the majority of the patients. Furthermore, recurrence is common after resection, most often in the remnant liver and likely because of microscopic residual disease in the setting of postoperative host cellular immune dysfunction. We hypothesize that, unlike other gene transfer approaches, direct injection of liver tumors with replication competent, oncolytic HSV expressing IL-12 will not only provide effective control of the parent tumor, but will also elicit an immune response directed at residual tumor cells, thus decreasing the risk of cancer recurrence after resection. Solitary Morris hepatomas, established in Buffalo rat livers, were injected directly with 10(7) particles of NV1042, NV1023, an oncolytic HSV identical to NV1042 but without the IL-12 gene, or with saline. Following tumor injection, the parent tumors were resected and measured and the animals were challenged with an intraportal injection of 10(5) tumor cells, recreating the clinical scenario of residual microscopic cancer. In vitro cytotoxicity against Morris hepatoma cells was similar for both viruses at a multiplicity of infection of 1 (MOI, ratio of viral particles to target cells), with >90% tumor cell kill by day 6. NV1042 induced high-level expression of IL-12 in vitro, peaking after 4 days in culture. Furthermore, a single intratumoral injection of NV1042, but not NV1023, induced marked IL-12 and interferon-gamma (IFN-gamma) expression. Both viruses induced a significant local immune response as evidenced by an increase in the number of intratumoral CD4(+) and CD8(+) lymphocytes, although the peak of CD8(+) infiltration was later with NV1042 compared with NV1023. NV1042 and NV1023 reduced parent tumor volume by 74% (P<.003) and 52% (P<.03), respectively, compared to control animals. Treatment of established tumors with NV1042, but not with NV1023, significantly reduced the number of hepatic tumors after resection of the parent tumor and rechallenge (16.8+/-11 (median=4) vs. 65.9+/-15 (median=66) in control animals, P<.025). In conclusion, oncolytic HSV therapy combined with local immune stimulation with IL-12 offers effective control of parent hepatic tumors and also protects against microscopic residual disease after resection. The ease of use of this combined modality approach, which appears to be superior to either approach alone, suggests that it may have clinical relevance, both as primary treatment for patients with unresectable tumors and also as a neoadjuvant strategy for reducing recurrence after resection.

Multiplex polymerase chain reaction for adenovirus and herpes simplex virus in eye swabs

Adenoviruses and herpes simplex virus (HSV) can cause clinically indistinguishable episodes of acute eye disease. Adenovirus infection is associated with nosocomial outbreaks and HSV may result in episodes of recurrent ocular inflammation. In a comparison of multiplex PCR for the two viral DNAs and virus isolation in cell culture, identical results were obtained for 18 of 20 specimens (positive for adenovirus in 5, HSV in 5, and negative in 8). One specimen was falsely negative for each viral DNA. Inclusion of human beta-globin primers in the adenovirus-HSV reaction was precluded by a consequential 10--100-fold reduction in sensitivity for the two viral targets and by the failure of beta-globin DNA amplification at the annealing temperature (45 degrees C) required to ensure detection of adenoviruses of serotypes 7 and 11 with the selected adenovirus primers. A single-target beta-globin PCR gave positive results with 19 of the 20 specimens prepared by treatment with proteinase K lysis buffer, indicating the effectiveness of this simple DNA extraction procedure. Nonetheless, the availability of effective antiviral therapy for HSV made monitoring for extraction failure using human primers crucial to avoid false-negative results for HSV DNA. Adenovirus-HSV PCR has considerable potential for the rapid diagnosis of viral eye disease particularly if beta-globin primers can be included in the reaction.

Therapy for herpes simplex virus with emphasis on the role of foscarnet

Therapy for herpes simplex virus with emphasis on the role of foscarnet

The structure and function of the HSV DNA replication proteins: Defining novel antiviral targets

The absolute dependence of herpes simplex virus (HSV) replication on HSV DNA polymerase and six other viral-encoded replication proteins implies that specific inhibitors of these proteins' functions would be potent antiviral agents. The only currently licensed anti-herpes simplex drug, acyclovir, is an inhibitor of HSV DNA polymerase and is widely held to block viral replication primarily by specifically inhibiting viral DNA replication. In spite of the substantial advance in HSV therapy in recent years through the introduction of acyclovir, this anti-HSV compound and most of the other compounds under pharmaceutical development are substrate analogs. Since antiviral drug resistance has become an issue of increasing clinical importance, the need for structurally unrelated agents which incorporate novel mechanisms of viral inhibition is apparent. Understanding the structure and function of herpesvirus DNA polymerase and its interaction with the other six essential replication proteins at the replication origin should assist us in designing the next generation of therapeutic agents. The sequences of these proteins have been deduced and the proteins themselves have been expressed and purified in a variety of systems. The current challenge, therefore, is to use the available information about these proteins to identify and develop new, exquisitely specific antiviral therapeutics. In this review, we have summarized the current approaches and the results of structure/function studies of the herpes virus proteins essential for DNA replication, with the goal of more precisely defining novel antiviral targets.

Foscarnet Therapy for Acyclovir-ResistantMucocutaneous Herpes Simplex Virus Infection in 26 AIDS Patients: Preliminary Data

Mucocutaneous herpes simplex virus (HSV) infections that are resistant to therapy with acyclovir have been recognized with increasing frequency in patients with the acquired immunodeficiency syndrome, although alternative therapies in this setting have not been widely studied. Twenty-six consecutive patients are reported with human immunodeficiency virus infection, who received foscarnet therapy for acyclovir-resistant HSV. Clinical response was noted in 81% of patients; complete reepithelialization of HSV lesions occurred in 73%. Cessation of viral shedding was documented in all of the 11 patients who were recultured. Although adverse effects were frequent, in only 3 patients (12%) did toxicity necessitate discontinuation of therapy. Before foscarnet therapy, 14 patients received vidarabine for acyclovir-resistant HSV. The infection did not resolve in any of the vidarabine-treated patients, and therapy was discontinued in 4 (29%) due to toxicity.

Successful Treatment with Foscarnet of an Acyclovir-Resistant Mucocutaneous Infection with Herpes Simplex Virus in a Patient with Acquired Immunodeficiency Syndrome

THE most widely used drug therapy for herpes simplex virus (HSV) is the nucleoside analogue acyclovir.1 2 3 To inhibit the growth of HSV, acyclovir must first be phosphorylated to the monophosphate...

Role of the virology laboratory in diagnosis and management of patients with central nervous system disease.

A number of viruses cause acute central nervous system disease. The two major clinical presentations are aseptic meningitis and the less common meningoencephalitis. Clinical virology laboratories are now more widely available than a decade ago; they can be operated on a modest scale and can be tailored to the needs of the patients they serve. Most laboratories can provide diagnostic information on diseases caused by enteroviruses, herpesviruses, and human immunodeficiency virus. Antiviral therapy for herpes simplex virus is now available. By providing a rapid diagnostic test or isolation of the virus or both, the virology laboratory plays a direct role in guiding antiviral therapy for patients with herpes simplex encephalitis. Although there is no specific drug available for enteroviruses, attention needs to be paid to these viruses since they are the most common cause of nonbacterial meningitis and the most common pathogens causing hospitalization for suspected sepsis in young infants in the United States during the warm months of the year. When the virology laboratory maximizes the speed of viral detection or isolation, it can make a significant impact on management of these patients. Early viral diagnosis benefits patients with enteroviral meningitis, most of whom are hospitalized and treated for bacterial sepsis or meningitis or both; these patients have the advantage of early withdrawal of antibiotics and intravenous therapy, early hospital discharge, and avoidance of the risks and costs of unnecessary tests and treatment. Enteroviral infection in young infants also is a risk factor for possible long-term sequelae. For compromised patients, the diagnostic information helps in selecting specific immunoglobulin therapy. Good communication between the physician and the laboratory will result in the most benefit to patients with central nervous system viral infection.

Use of interleukin-2 and macrophages to treat herpes simplex virus infection in neonatal mice.

We have developed a model of therapy for herpes simplex virus (HSV) infection in neonatal mice. Using a lower dose of virus (10(2) plaque-forming units administered intraperitoneally), we have been able to treat infected mice with syngeneic or allogeneic adult mouse macrophages in combination with three doses of human recombinant interleukin-2. Therapy resulted in a 42%-85% survival rate. Although production of antibody to HSV was associated with successful treatment, early administration of antibody did not improve survival.