Activation of the human immunodeficiency virus by herpes simplex virus type 1

Comparison of Effects of Multiple Adjuvants and Immunization Routes on the Immunogenicity and Protection of HSV-2 gD Subunit Vaccine

Genital herpes caused by herpes simplex virus type 2 (HSV-2) poses a global health issue. HSV-2 infection increases the risk of acquiring HIV infection. Studies have demonstrated that HSV-2 subunit vaccines have potential benefits, but require adjuvants to induce a balanced Th1/Th2 response. To develop a novel, effective vaccine, in this study, a truncated glycoprotein D (aa 1-285) of HSV-2 was formulated with an Al(OH)₃ adjuvant, three squalene adjuvants, MF59, AS03, and AS02, or a mucosal adjuvant, bacterium-like particles (BLPs). The immunogenicity of these subunit vaccines was evaluated in mice. After three immunizations, vaccines formulated with Al(OH)_3, MF59, AS03, and AS02 (intramuscularly) induced higher titers of neutralizing antibody than that formulated without adjuvant, and in particular, mice immunized with the vaccine plus AS02 had the highest neutralizing antibody titers and tended to produce a more balanced immune reaction than others. Intranasal gD2-PA-BLPs also induced excellent IgA levels and a more balanced Th1 and Th2 responses than intranasal gD2. After challenge with a lethal dose of HSV-2, all five adjuvants exhibited a positive effect in improving the survival rate. AS02 and gD2-PA-BLPs enhanced survival by 50% and 25%, respectively, when compared with the vaccine without adjuvant. AS02 was the only adjuvant that resulted in complete vaginal virus clearance and genital lesion healing within eight days. These results demonstrate the potential of using AS02 as a subunit vaccine adjuvant, and BLPs as a mucosal vaccine adjuvant.

"Non-Essential" Proteins of HSV-1 with Essential Roles In Vivo: A Comprehensive Review

Viruses encode for structural proteins that participate in virion formation and include capsid and envelope proteins. In addition, viruses encode for an array of non-structural accessory proteins important for replication, spread, and immune evasion in the host and are often linked to virus pathogenesis. Most virus accessory proteins are non-essential for growth in cell culture because of the simplicity of the infection barriers or because they have roles only during a state of the infection that does not exist in cell cultures (i.e., tissue-specific functions), or finally because host factors in cell culture can complement their absence. For these reasons, the study of most nonessential viral factors is more complex and requires development of suitable cell culture systems and in vivo models. Approximately half of the proteins encoded by the herpes simplex virus 1 (HSV-1) genome have been classified as non-essential. These proteins have essential roles in vivo in counteracting antiviral responses, facilitating the spread of the virus from the sites of initial infection to the peripheral nervous system, where it establishes lifelong reservoirs, virus pathogenesis, and other regulatory roles during infection. Understanding the functions of the non-essential proteins of herpesviruses is important to understand mechanisms of viral pathogenesis but also to harness properties of these viruses for therapeutic purposes. Here, we have provided a comprehensive summary of the functions of HSV-1 non-essential proteins.

Subclinical Genital Herpes Shedding in HIV/Herpes Simplex Virus 2-Coinfected Women during Antiretroviral Therapy Is Associated with an Increase in HIV Tissue Reservoirs and Potentially Promotes HIV Evolution

Antigen (Ag)-specific immune responses to chronic infections, such as herpes simplex virus type 2 (HSV-2) in HIV/HSV-coinfected persons, may sustain HIV tissue reservoirs by promoting T-cell proliferation but are poorly studied in women on antiretroviral therapy (ART). Mixed anogenital swabs and cervical secretions were self-collected by nine HIV/HSV-2-coinfected women during ART for 28 days to establish subclinical HSV DNA shedding rates and detection of HIV RNA by real-time PCR. Typical herpes lesion site biopsy (TLSB) and cervical biopsy specimens were collected at the end of the daily sampling period. Nucleic acids (NA) isolated from biopsy specimens had HIV quantified and HIV envC2-V5 single-genome amplification (SGA) and T-cell receptor (TCR) repertoires assessed. Women had a median CD4 count of 537 cells/μl (IQR: 483 to 741) at enrollment and HIV plasma viral loads of <40 copies/ml. HSV DNA was detected on 12% of days (IQR: 2 to 25%) from anogenital specimens. Frequent subclinical HSV DNA shedding was associated with increased HIV DNA tissue concentrations and increased divergence from the most recent common ancestor (MRCA), an indicator of HIV replication. Distinct predominant TCR clones were detected in cervical and TLSB specimens in a woman with frequent HSV DNA shedding, with mixing of minor variants between her tissues. In contrast, more limited TCR repertoire mixing was observed in two women with less frequent subclinical HSV DNA shedding. Subclinical HSV shedding in HIV/HSV-coinfected women during ART may sustain HIV tissue reservoirs via Ag exposure or HIV replication. This study provides evidence supporting further study of interventions targeting suppression of Ag-specific immune responses as a component of HIV cure strategies.IMPORTANCE Persons with HIV infection are frequently coinfected with chronic herpesviruses, which periodically replicate and produce viable herpes virions, particularly in anogenital and cervical tissues. Persistent protein expression results in proliferation of CD8+ and CD4+ T cells, and the latter could potentially expand and sustain HIV tissue reservoirs. We found HSV genital shedding rates were positively correlated with HIV DNA concentrations and HIV divergence from ancestral sequences in tissues. Our work suggests that immune responses to common coinfections, such as herpesviruses, may sustain HIV tissue reservoirs during suppressive ART, suggesting future cure strategies should study interventions to suppress replication or reactivation of chronic herpes infections.

HSV-2 glycoprotein J promotes viral protein expression and virus spread

HSV-2 spread is predominantly dependent on cell-to-cell contact. However, the underlying mechanisms remain to be determined. Here we demonstrate that HSV-2 gJ, which was previously assigned no specific function, promotes HSV-2 cell-to-cell spread and syncytia formation. In the context of viral infection, knockout or knockdown of gJ impairs HSV-2 cell-to-cell spread among epithelial cells or from epithelial cells to neuronal cells, which leads to decreased virus production, whereas ectopic expression of gJ enhances virus production. Mechanistically, gJ increases the expression levels of HSV-2 proteins, and also enhances viral protein expression and replication of heterologous viruses like HIV-1 and JEV, suggesting that HSV-2 gJ likely functions as a regulator of viral protein expression and virus production. Findings in this study provide a basis for further understanding the role of gJ in HSV-2 replication.

Herpesviruses: Harmonious Pathogens but Relevant Cofactors in Other Diseases?

Most vertebrates are infected with one or more herpesviruses and remain so for the rest of their lives. The relationship of immunocompetent healthy host with herpesviruses may sometime be considered as harmonious. However, clinically severe diseases can occur when host immunity is compromised due to aging, during some stress response, co-infections or during neoplastic disease conditions. Discord can also occur during iatrogenic immunosuppression used for controlling graft rejection, in some primary genetic immunodeficiencies as well as when the virus infects a non-native host. In this review, we discuss such issues and their influence on host-herpesvirus interaction.

2017 European guidelines for the management of genital herpes

Genital herpes is one of the commonest sexually transmitted infections worldwide. Using the best available evidence, this guideline recommends strategies for diagnosis, management, and follow-up of the condition as well as for minimising transmission. Early recognition and initiation of therapy is key and may reduce the duration of illness or avoid hospitalisation with complications, including urinary retention, meningism, or severe systemic illness. The guideline covers a range of common clinical scenarios, such as recurrent genital herpes, infection during pregnancy, and co-infection with human immunodeficiency virus.

Anti-herpes simplex virus type 1 activity of Houttuynoid A, a flavonoid from Houttuynia cordata Thunb

Early events in herpes simplex virus type 1 (HSV-1) infection reactivate latent human immunodeficiency virus, Epstein-Barr virus, and human papillomavirus in the presence of acyclovir (ACV). The common use of nucleoside analog medications, such as ACV and pencyclovir, has resulted in the emergence of drug-resistant HSV-1 strains in clinical therapy. Therefore, new antiherpetics that can inhibit early events in HSV-1 infection should be developed. An example of this treatment is Houttuynia cordata Thunb. water extract, which can inhibit HSV-1 infection through multiple mechanisms. In this study, the anti-HSV-1 activity of Houttuynoid A, a new type of flavonoid isolated from H. cordata, was investigated. Three different assays confirmed that this compound could exhibit strong in vitro anti-HSV-1 activity. One assay verified that this compound could inhibit HSV-1 multiplication and prevent lesion formation in a HSV-1 infection mouse model. Mechanism analysis revealed that this compound could inactivate HSV-1 infectivity by blocking viral membrane fusion. Moreover, Houttuynoid A exhibited antiviral activities against other alpha herpes viruses, such as HSV-2 and varicella zoster virus (VZV). In conclusion, Houttuynoid A may be a useful antiviral agent for HSV-1.

Effect of Herpesvirus Inhibition on Primary SIV Infection in Cynomolgus Monkeys

Foscarnet and (-)9-[4-hydroxy-2-(hydroxymethyl)butyl] guanine (H2G) have already been shown to inhibit herpesviruses in vitro and also to inhibit viral antigen production in primary SIV infection in monkeys. Attempts have been made to determine if these invivo effects on SIV were due to a direct effect on SIV or were mediated through inhibition of endogenous transactivating herpesviruses. The possible involvement of herpesviruses in primary SIVsm infection in monkeys was studied by the use of various inhibitors of herpesvirus replication. Subcutaneous injections of 3 × 5 mg kg−1 day−1 of aciclovir, 3 × 5 mg kg−1 day−1 of ganciclovir and 3 × 28 mg kg−1 day−1 of phosphonoacetic acid had no effect on primary SIVsm infection in cynomolgus monkeys. These doses of aciclovir, ganciclovir and phosphonoacetic acid are inhibitory to several herpesviruses. The results suggest that the effects of foscarnet and H2G on primary SIVsm infection in monkeys are direct and not mediated through inhibition of a replicating herpesvirus.

2014 UK national guideline for the management of anogenital herpes

These guidelines concern the management of anogenital herpes simplex virus infections in adults and give advice on diagnosis, management, and counselling of patients. This guideline replaces the 2007 BASHH herpes guidelines and includes new sections on herpes proctitis, key points to cover with patients regarding transmission and removal of advice on the management of HSV in pregnancy which now has a separate joint BASHH/RCOG guideline.

An indole alkaloid from a tribal folklore inhibits immediate early event in HSV-2 infected cells with therapeutic efficacy in vaginally infected mice

Herpes genitalis, caused by HSV-2, is an incurable genital ulcerative disease transmitted by sexual intercourse. The virus establishes life-long latency in sacral root ganglia and reported to have synergistic relationship with HIV-1 transmission. Till date no effective vaccine is available, while the existing therapy frequently yielded drug resistance, toxicity and treatment failure. Thus, there is a pressing need for non-nucleotide antiviral agent from traditional source. Based on ethnomedicinal use we have isolated a compound 7-methoxy-1-methyl-4,9-dihydro-3H-pyrido[3,4-b]indole (HM) from the traditional herb Ophiorrhiza nicobarica Balkr, and evaluated its efficacy on isolates of HSV-2 in vitro and in vivo. The cytotoxicity (CC₅₀), effective concentrations (EC₅₀) and the mode of action of HM was determined by MTT, plaque reduction, time-of-addition, immunofluorescence (IFA), Western blot, qRT-PCR, EMSA, supershift and co-immunoprecipitation assays; while the in vivo toxicity and efficacy was evaluated in BALB/c mice. The results revealed that HM possesses significant anti-HSV-2 activity with EC₅₀ of 1.1-2.8 µg/ml, and selectivity index of >20. The time kinetics and IFA demonstrated that HM dose dependently inhibited 50-99% of HSV-2 infection at 1.5-5.0 µg/ml at 2-4 h post-infection. Further, HM was unable to inhibit viral attachment or penetration and had no synergistic interaction with acyclovir. Moreover, Western blot and qRT-PCR assays demonstrated that HM suppressed viral IE gene expression, while the EMSA and co-immunoprecipitation studies showed that HM interfered with the recruitment of LSD-1 by HCF-1. The in vivo studies revealed that HM at its virucidal concentration was nontoxic and reduced virus yield in the brain of HSV-2 infected mice in a concentration dependent manner, compared to vaginal tissues. Thus, our results suggest that HM can serve as a prototype to develop non-nucleotide antiviral lead targeting the viral IE transcription for the management of HSV-2 infections.

Herpes simplex virus type 2 triggers reactivation of Kaposi's sarcoma-associated herpesvirus from latency and collaborates with HIV-1 Tat

Kaposi's sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for Kaposi's sarcoma (KS) development without other cofactors. Previously, we identified that both human immunodeficiency type 1 (HIV-1) Tat and herpes simplex virus 1 (HSV-1) were important cofactors reactivating KSHV from latency. Here, we further investigated the potential of herpes simplex virus 2 (HSV-2) to influence KSHV replication and examined the role of Tat in this procedure. We demonstrated that HSV-2 was a potentially important factor in the pathogenesis of KS, as determined by production of lytic phase mRNA transcripts, viral proteins and infectious viral particles in BCBL-1 cells. These results were further confirmed by an RNA interference experiment using small interfering RNA targeting KSHV Rta and a luciferase reporter assay testing Rta promoter-driven luciferase activity. Mechanistic studies showed that HSV-2 infection activated nuclear factor-kappa B (NF-κB) signaling pathway. Inhibition of NF-κB pathway enhanced HSV-2-mediated KSHV activation, whereas activation of NF-κB pathway suppressed KSHV replication in HSV-2-infected BCBL-1 cells. Additionally, ectopic expression of Tat enhanced HSV-2-induced KSHV replication. These novel findings suggest a role of HSV-2 in the pathogenesis of KS and provide the first laboratory evidence that Tat may participate HSV-2-mediated KSHV activation, implying the complicated pathogenesis of acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients.

Horizontal gene transfers with or without cell fusions in all categories of the living matter

This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.

Antileukemia and antitumor effects of the graft-versus-host disease: a new immunovirological approach

In leukemic mice, the native host's explicit and well-defined immune reactions to the leukemia virus (a strong exogenous antigen) and to leukemia cells (pretending in their native hosts to be protected "self" elements) are extinguished and replaced in GvHD (graft-versus-host disease) by those of the immunocompetent donor cells. In many cases, the GvHD-inducer donors display genetically encoded resistance to the leukemia virus. In human patients only antileukemia and anti-tumor cell immune reactions are mobilized; thus, patients are deprived of immune reactions to a strong exogenous antigen (the elusive human leukemia-sarcoma retroviruses). The innate and adaptive immune systems of mice have to sustain the immunosuppressive effects of leukemia-inducing retroviruses. Human patients due to the lack of leukemiainducing retroviral pathogens (if they exist, they have not as yet been discovered), escape such immunological downgrading. After studying leukemogenic retroviruses in murine and feline (and other mammalian) hosts, it is very difficult to dismiss retroviral etiology for human leukemias and sarcomas. Since no characterized and thus recognized leukemogenic-sarcomagenic retroviral agents are being isolated from the vast majority of human leukemias-sarcomas, the treatment for these conditions in mice and in human patients vastly differ. It is immunological and biological modalities (alpha interferons; vaccines; adoptive lymphocyte therapy) that dominate the treatment of murine leukemias, whereas combination chemotherapy remains the main remission-inducing agent in human leukemias-lymphomas and sarcomas (as humanized monoclonal antibodies and immunotoxins move in). Yet, in this apparently different backgrounds in Mus and Homo, GvHD, as a treatment modality, appears to work well in both hosts, by replacing the hosts' anti-leukemia and anti-tumor immune faculties with those of the donor. The clinical application of GvHD in the treatment of human leukemias-lymphomas and malignant solid tumors remains a force worthy of pursuit, refinement and strengthening. Graft engineering and modifications of the inner immunological environment of the recipient host by the activation or administration of tumor memory T cells, selected Treg cells and natural killer (NKT) cell classes and cytokines, and the improved pharmacotherapy of GvHD without reducing its antitumor efficacy, will raise the value of GvHD to the higher ranks of the effective antitumor immunotherapeutical measures. Clinical interventions of HCT/HSCT (hematopoietic cell/stem cell transplants) are now applicable to an extended spectrum of malignant diseases in human patients, being available to elderly patients, who receive non-myeloablative conditioning, are re-enforced by post-transplant donor lymphocyte (NK cell and immune T cell) infusions and post-transplant vaccinations, and the donor cells may derive from engineered grafts, or from cord blood with reduced GvHD, but increased GvL/GvT-inducing capabilities (graft-versus leukemia/tumor). Post-transplant T cell transfusions are possible only if selected leukemia antigen-specific T cell clones are available. In verbatim quotation: "Ultimately, advances in separation of GvT from GvHD will further enhance the potential of allogeneic HCT as a curative treatment for hematological malignancies" (Rezvani, A.R. and Storb, R.F., Journal of Autoimmunity 30:172-179, 2008 (see in the text)). It may be added: for cure, a combination of the GvL/T effects with new targeted therapeutic modalities, as elaborated on in this article, will be necessary.

The transactivating effect of HSV-1 ICP0 is enhanced by its interaction with the PCAF component of histone acetyltransferase

ICP0 is a multifunctional protein that plays diverse roles in herpes simplex virus type 1 (HSV-1) infection. It can promote the lytic replication of HSV-1 and activate a variety of viral or cellular genes when introduced into cells by transfection or infection. However, the exact mechanism of ICP0 action is not fully understood. In the present study, we observed the co-localization of ICP0 and PCAF (P300/CBP-associated factor), a component of histone acetyltransferase (HAT), in the ND10 (nuclear dot 10) nuclear body. We further confirmed the interaction between ICP0 and PCAF via yeast two-hybrid assay, co-immunoprecipitation, and histone acetyltransferase assays. Analysis of the functional significance of this interaction suggested that PCAF improved the ability of ICP0 to activate transcription of viral genes. Using chromatin immunoprecipitation (ChIP) assays, we observed ICP0-enhanced histone acetylation levels in both viral and cellular gene promoters. Our study suggests that ICP0 regulates transcription through specific interaction with PCAF.

Adenovirus vectors block human immunodeficiency virus-1 replication in human alveolar macrophages by inhibition of the long terminal repeat

Heterologous viruses may transactivate or suppress human immunodeficiency virus (HIV)-1 replication. An adenovirus type 5 gene transfer vector (Ad5) HIV-1 vaccine was recently evaluated in a clinical trial, without efficacy. In this context, it is relevant to ask what effect Ad vectors have on HIV-1 replication, particularly in cells that are part of the innate immune system. Infection of HIV-1-infected human alveolar macrophages (AMs) obtained from HIV-1(+) individuals with an Ad vector containing no transgene (AdNull) resulted in dose-responsive inhibition of endogenous HIV-1 replication. HIV-1 replication in normal AMs infected with HIV-1 in vitro was inhibited by AdNull with a similar dose response. Ad reduced AM HIV-1 replication up to 14 days after HIV-1 infection. Fully HIV-1-infected AMs were treated with 3'-azido-3'-deoxythymidine, after which Ad infection still inhibited HIV-1 replication, suggesting a postentry step was affected. Substantial HIV-1 DNA was still produced after Ad infection, as quantified by TaqMan real-time PCR, suggesting that the replication block occurred after reverse transcription. AdNull blocked HIV-1 long terminal repeat (LTR) transcription, as assessed by an vesicular stomatitis virus G protein pseudotyped HIV-1 LTR luciferase construct. The formation of HIV-1 DNA integrated into the host chromosome was not inhibited by Ad, as quantified by a two-step TaqMan real-time PCR assay, implying a postintegration block to HIV-1 replication. These data indicate that Ad vectors are inhibitory to HIV-1 replication in human AMs based, in part, on their ability to inhibit LTR-driven transcription.

Impact of aciclovir on genital and plasma HIV-1 RNA in HSV-2/HIV-1 co-infected women: a randomized placebo-controlled trial in South Africa

BACKGROUND

Several studies suggest that herpes simplex virus type 2 (HSV-2) may enhance HIV-1 transmission and disease progression.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of aciclovir 400 mg twice daily for 3 months in 300 HSV-2/HIV-1 co-infected women not yet on highly active antiretroviral therapy (HAART). Participants were evaluated prerandomization and at monthly visits for 3 months. Primary outcomes were the detection and quantity of genital HIV-1 RNA at the month 3 (M3) visit. Analyses were also undertaken using data from all visits. The treatment effects on plasma HIV-1 RNA, CD4 cell count and genital HSV-2 DNA were also assessed.

RESULTS

At M3 fewer women had detectable genital HIV in the aciclovir group compared to placebo, but this was not significant [61/132 (46%) vs. 71/137 (52%), risk ratio (RR) 0.89, 95% confidence interval (CI) 0.70-1.14; P = 0.36]. There was also little difference in quantity of HIV-1 RNA among shedders (+0.13 log10 copies/ml, 95% CI -0.14 to 0.39) at M3. However, aciclovir significantly decreased the frequency of HIV-1 shedding over all visits [adjusted odds ratio (OR) 0.57, 95% CI 0.36-0.89]. Significant reductions in M3 plasma HIV-1 RNA (-0.34 log10 copies/ml, 95% CI 0.15-0.54), genital HSV-2 DNA (8 vs. 20%, RR 0.37, 95% CI 0.19-0.73) and genital ulceration (8 vs. 18%, RR 0.43, 95% CI 0.22-0.84) were observed in the aciclovir group.

CONCLUSION

HSV-2 suppressive therapy, by reducing HIV-1 plasma viral load and altering the pattern of genital HIV-1 shedding, may contribute to the reduction in sexual transmission of HIV-1 and may delay the requirement for HAART initiation.

Ethnomedicines and ethnomedicinal phytophores against herpesviruses

Herpesviruses are important human pathogens that can cause mild to severe lifelong infections with high morbidity in susceptible adults. Moreover, Herpes simplex virus (HSV) type 2, for example, has been reported to be responsible for increased transmission and disease progression of human immunodeficiency virus (HIV). Therefore, the discovery of novel anti-HSV drugs deserves great efforts. Herbal medicinal products have been used as source of putative candidate drugs in many diseases. However, in case of viral diseases the development of antivirals from natural source is less explored probably because within the virus there are few specific targets where the small molecules can interact to inhibit or kill the virus. The currently available antiherpes drugs are nucleoside analogs that did not cure the lifelong or recurrent infections and the use of these drugs often lead to the development of viral resistance coupled with the problem of side effects, recurrence and viral latency. However a wide array of herbal products, used by diverse medicinal systems throughout the world, showed high level of antiherpesvirus activities and many of them have complementary and overlapping mechanism of action, either by inhibiting viral replication, or viral genome synthesis. This chapter will summarize some of the promising herbal extracts and purified compounds isolated from the herbal sources by several laboratories. Cases with proven in vitro and documented in vivo activities, along with their structure-activity relationship against herpesviruses are discussed.

Interactions and management issues in HSV and HIV coinfection

Significant synergistic interactions have been observed between HIV and herpes simplex virus (HSV). HIV-induced immune compromise can cause frequent and persistent HSV disease, while poorly controlled HSV replication may influence HIV pathogenicity and transmission. HSV-2 seroprevalence is high in HIV-infected cohorts worldwide, with rates of over 80% for HSV-1 and ranging from 33% to more than 80% for HSV-2. As seen in HIV-negative individuals, HSV-2 coinfection is associated with female gender, older age and black ethnicity. HSV infection is commonly under-diagnosed in HIV-infected individuals, although the use of PCR for HSV detection in mucocutaneous swabs and HSV type-specific serology can improve the diagnostic yield. In HIV-1-infected patients with frequent clinical episodes of HSV reactivation, suppressive antiviral therapy may prove beneficial in controlling HSV disease while also reducing HSV-mediated promotion of HIV replication. Antiretroviral therapy leads to a gradual recovery of HSV-specific T-cell responses and a reduction in HSV-related morbidity, indicating that successful management of coinfection should target both HIV and HSV replication. The aim of this review is to address the more speculative issues surrounding the management of HSV/HIV coinfection and to summarize the data that inform them.

Reciprocal transactivation between HIV-1 and other human viruses

A variety of rare clinical syndromes are seen with strikingly increased prevalence in HIV-1-infected individuals, many with underlying viral etiologies. The emergence of these diseases in AIDS reflects a reduction in the ability of the immune system to mount an adequate defense against viruses in general due to the damage inflicted to the immune system by HIV-1 infection. However, in many cases, it has been found that HIV-1 can enhance the level of expression and hence the life cycle of other viruses independently of immunosuppression through specific interactions with the viruses. This can occur either directly by HIV-1 proteins such as Tat enhancing the activity of heterologous viral promoters, and/or indirectly by HIV-1 inducing the expression of cytokines and activation of their downstream signaling that eventually promotes the multiplication of the other virus. In a reciprocal manner, the effects of other viruses can enhance the pathogenicity of HIV-1 infection in individuals with AIDS through stimulation of the HIV-1 promoter activity and genome expression. The purpose of this review is to examine the cross-interactions between these viruses and HIV-1.

Antiherpetic activities of flavonoids against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in vitro

Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant, anticancer, bactericidal, and anti-inflammatory. We carried out anti-herpetic assays on 18 flavonoids in five classes and a virus-induced cytopathic effect (CPE) inhibitory assay, plaque reduction assay, and yield reduction assay were performed. When flavonoids were applied at various concentrations to Vero cells infected by HSV-1 and 2, most of the flavonoids showed inhibitory effects on virus-induced CPE. Among the flavonoids, EC, ECG (flavanols), genistein (isoflavone), naringenin (flavanone), and quercetin (flavonol) showed a high level of CPE inhibitory activity. The antiviral activity of flavonoids were also examined by a plaque reduction assay. EC, ECG, galangin, and kaempferol showed a strong antiviral activity, and catechin, EGC, EGCG, naringenin, chrysin, baicalin, fisetin, myricetin, quercetin, and genistein showed moderate inhibitory effects against HSV-1. In these experiments, flavanols and flavonols appeared to be more active than flavones. Furthermore, treatment of Vero cells with ECG and galangin (which previously showed strong antiviral activities) before virus adsorption led to a slight enhancement of inhibition as determined by a yield reduction assay, indicating that an intracellular effect may also be involved.

Activation of c-Jun N-terminal kinase (JNK) pathway by HSV-1 immediate early protein ICP0

The immediate early protein ICP0 encoded by herpes simplex virus 1 (HSV-1) is believed to activate transcription and consequently productive infection. The precise mechanisms of ICP0-mediated transactivation are under intensive study. Here, we demonstrate that ICP0 can strongly activate AP-1 responsive genes specifically. This activation is inhibited by c-Jun (S73A), c-Jun (S63/73A), TAK1 (K63W), but not by p38 (AF), ERK1 (K71R), ERK2 (K52R) and TRAF6 (C85A/H87A). We further investigate the relevancy of ERK, JNK and p38 MAPK pathways using their respective inhibitors PD98059, SP600125 and SB202190. Only SP600125 significantly attenuates the AP-1 responsive gene activation by ICP0. Consistent with these, the JNK is remarkably activated in response to ICP0, and this JNK activation is shown to be significantly attenuated by TAK1 (K63W). It turns out that ICP0 interacts specifically with TAK1 and stimulates its kinase activity. These findings reveal a new molecular mechanism ICP0 explores to regulate gene expression.

Herpes virus proteins ICP0 and BICP0 can activate NF-κB by catalyzing IκBα ubiquitination

The immediate early proteins ICP0 and BICP0 from Herpes virus are promiscuous activators of both viral and cellular genes and play a critical role in virus life cycle. Here we report that ICP0 and BICP0 could induce NF-kappaB translocation from cytoplasm into nucleus and strongly activate NF-kappaB responsive genes specifically. This process was dependent on the RING domain of both proteins. In addition, ICP0 interacted specifically with IkappaBalpha and its activating effect was attenuated by Ubch5A(C85A) and MG132, but not by IkappaBalpha(S32A/S36A). Remarkably, IkappaBalpha was poly-ubiquitinated by both ICP0 and BICP0, in vitro and in vivo. These data indicate that ICP0 and BICP0, functioning as ubiquitin ligases, are bona fide activators of NF-kappaB signaling pathway. Our study identifies a new way ICP0 and BICP0 explore to regulate gene expression.

Herpes simplex virus type 2 and heterosexual spread of human immunodeficiency virus infection in developing countries: hypotheses and research priorities

Herpes simplex virus type 2 (HSV-2) infection is almost always sexually transmitted, and causes genital ulceration. Significant progress in our understanding of HSV infection has occurred over the last decade, in part related to the development of accurate and sensitive laboratory tests to study HSV-2. The application of PCR and type-specific serology to individual cases and in population-based studies has enabled the identification of a potentially important role for HSV-2 infection as a cofactor in the sexual transmission of HIV. This is a particular issue in developing countries. This review describes the epidemiology of HSV-2 infection in the HIV era, the hypotheses regarding HSV-HIV interactions, and research priorities for the developing world.

Antiviral properties of prodelphinidin B-2 3'-O-gallate from green tea leaf

Prodelphinidin B-2 3-O-gallate, a proanthocyanidin gallate isolated from green tea leaf, was investigated for its anti-herpes simplex virus type 2 properties in vitro. Prodelphinidin B-2 3'-O-gallate exhibited antiviral activity with IC50 of 5.0 +/-1.0 microM and 1.6 +/-0.3 pM for XTT and plaque reduction (PRA) assays, respectively. Cytotoxicity assay had shown that prodelphinidin B-2 3'-O-gallate possessed cytotoxic effect toward Vero cell at concentration higher than its IC50. The 50% cytotoxic concentration for cell growth (CC50) was 33.3 +/- 3.7 microM. Thus, the selectivity index (SI) (ratio of IC50 to CC50) for XTT assay and PRA was 6.7 and 20.8, respectively. Prodelphinidin B-2 3'-O-gallate significantly reduced viral infectivity at concentrations 10 microM or more. Result of time-of-addition studies suggested that prodelphinidin B-2 3'-O-gallate affected the late stage of HSV-2 infection. In addition, it was also shown to inhibit the virus from attaching and penetrating into the cell. Thus, prodelphinidin B-2 3'-O-gallate was concluded to possess antiviral activity with mechanism of inhibiting viral attachment and penetration, and disturbing the late stage of viral infection.

Synergism between HIV and other viruses in the mouth

The HIV family replicate in and are shed from the mouth. Oral sexual practices potentially contribute to the overall extent of HIV transmission, particularly if high-risk practices are not restricted. Herpesviruses and papillomaviruses that appear in the oral cavity can determine oral HIV replication. The mechanisms probably include heterologous transactivation, enhanced expression of HIV receptors and co-receptors in target cells, release of cytokines and chemokines, and production of superantigens. Oral diseases peculiar to, or more common in, the HIV-infected patient further predispose to heightened oral HIV replication and trafficking. Defining the mechanisms by which oral viruses interact with HIV in the co-infected host should permit intervention measures against oral HIV transmission to be more precisely targeted.

Herpes simplex virus shedding and plasma human immunodeficiency virus RNA levels in coinfected women

Asymptomatic herpes simplex virus (HSV) shedding was described in a cohort of human immunodeficiency virus (HIV)-infected women, and the association of HSV shedding with changes in plasma HIV RNA load was investigated. Genital, rectal, and oral swabs were obtained daily during a 4-week period for polymerase chain reaction and culture, and concomitant plasma specimens were drawn 3 times weekly for determination of HIV RNA load. During the study, 70% and 79% of subjects shed HSV from the oral cavity and genital area, respectively. Shedding of HSV occurred for a mean of 3.2 days for oral shedding and 5.4 days for genital shedding. Mean plasma HIV RNA loads during periods of HSV shedding and nonshedding and for periods 3 days after the cessation of shedding were compared; no significant differences were found (P=.74). In women who shed HSV, as evaluated by detection of virus, plasma HIV RNA load did not fluctuate with HSV shedding.

Cofactors for HIV disease progression in a cohort of homosexual and bisexual men

To evaluate cofactors for progression of HIV infection, the authors identified 370 men with well-defined seroconversion dates and cofactor data among participants in the San Francisco City Clinic Cohort (SFCCC). Postseroconversion substance use, sexual behavior, and sexually transmitted diseases were assessed using multivariate proportional hazards models. Weekly use of hallucinogens strongly and independently predicted death (relative hazard [RH], 2.59; 95% confidence interval [CI], 1.56-4.28), as well as diagnosis of AIDS; weekly cocaine use also predicted mortality. Receptive anal intercourse with ejaculation was independently associated with mortality risk (RH, 1.45; 95% CI, 1.02-2.04) and AIDS. The associations of accelerated progression with weekly use of recreational drugs and unprotected receptive anal intercourse need to be confirmed in other prospective cohorts.

The herpes simplex virus 1 Us11 protein cooperates with suboptimal amounts of human immunodeficiency virus type 1 (HIV-1) Rev protein to rescue HIV-1 production

The human immunodeficiency virus type 1 (HIV-1) RNA-binding Rev protein governs the expression of structural and enzymatic viral proteins at a posttranscriptional level. Binding of Rev to the stem-loop IIB (SLIIB) sequence of the Rev-response element (RRE) within unspliced and singly spliced viral mRNAs and to the nuclear export signal-binding receptor, hCRM1 (or exportin 1), is required for the export of these transcripts to the cytoplasm. We have previously shown that herpes simplex virus type 1 (HSV-1) RNA-binding Us11 protein is able to bind the RRE and substitute for Rev in inducing the expression of HIV-1 envelope glycoproteins. We show here that Us11 cannot substitute for Rev in rescuing a rev-deleted HIV-1 provirus. However, HIV-1 production is observed when Us11 is expressed with suboptimal amounts of Rev. An in vivo RNA-protein binding assay indicates that Us11 is unable to directly interact with the SLIIB RNA but can bind Rev assembled on that stem-loop structure. This association of US11 with Rev, which was confirmed by in vivo coimmunoprecipitation and GST-pulldown assays, therefore underlies a biological Us11-Rev cooperation. Furthermore this cooperation was shown to remain susceptible to the effect of leptomycin B, which blocks the binding of hCRM1 to the nuclear export signal of Rev. These observations performed with intron-containing constructs provide evidence that HSV-1 Us11 protein is not directly involved in the cytoplasmic accumulation of viral mRNAs but may be rather acting as an auxiliary protein, thus allowing this retroviral protein to fulfill the nuclear export of these transcripts and to rescue HIV-1 production.

Comparative pathology and pathogenesis of spontaneous and experimentally induced fibropapillomas of green turtles (Chelonia mydas)

Tumor biopsy samples from 25 Floridian and 15 Hawaiian green turtles (Chelonia mydas) with spontaneous green turtle fibropapillomatosis (GTFP) and from 27 captive-reared green turtles with experimentally induced GTFP were examined microscopically to differentiate the histologic features that result from GTFP pathogenesis and those that result from incidental factors that may vary according to geographic region. Common histologic features for spontaneous and experimentally induced tumors included fibroblast proliferation in the superficial dermis, epidermal acanthosis and hyperkeratosis, epidermal basal cell degeneration with dermal-epidermal cleft formation, spinous layer degeneration with intraepidermal vesicle and pustule formation, and ulceration. Visceral tumors, found in eight of 10 (80%) free-ranging turtles with cutaneous disease that were examined after death, had extensive interstitial fibrous proliferation. The presence of spirorchid trematode eggs and associated foreign body granulomas, common secondary findings within spontaneous tumors, varied by geographic location, and these findings were not observed in experimentally induced tumors. Eosinophilic intranuclear inclusions and intranuclear herpesvirus-associated antigen immunoreactivity were found in 18 of 38 (47%) experimentally induced cutaneous tumors and nine of 119 (7.5%) spontaneous tumors from Floridian but not Hawaiian turtles. The possible involvement of GTFP-associated herpesvirus in the pathogenesis of epidermal degenerative changes and GTFP pathogenesis is discussed.

Antiviral properties of isoborneol, a potent inhibitor of herpes simplex virus type 1

Isoborneol, a monoterpene and a component of several plant essential oils, showed dual viricidal activity against herpes simplex virus 1 (HSV-1). First, it inactivated HSV-1 by almost 4 log10 values within 30 min of exposure, and second, isoborneol at a concentration of 0.06% completely inhibited viral replication, without affecting viral adsorption. Isoborneol did not exhibit significant cytotoxicity at concentrations ranging between 0.016% and 0.08% when tested against human and monkey cell lines. Isoborneol specifically inhibited glycosylation of viral polypeptides based on the following data: (1) the mature fully glycosylated forms of two viral glycoproteins gB and gD were not detected when the virus was replicated in the presence of isoborneol, (2) no major changes were observed in the glycosylation pattern of cellular polypeptides between untreated and isoborneol treated Vero cells, (3) isoborneol did not affect the glycosylation of gB produced from a copy of the gB gene resident in the cellular genome, and (4) other monoterpenes such as 1,8-cineole and borneol, a stereoisomer of isoborneol, did not inhibit HSV-1 glycosylation.

Dimethyldithiocarbamate inhibits in vitro activation of primary human CD4+ T lymphocytes

Dithiocarbamates (DTC), a diverse group of industrial and therapeutic chemicals, have been reported to inhibit, enhance or have no effect on the immune system. These apparent inconsistencies reflect the complexity of the DTCs biological activities and are probably due in part to differences in dose, route of exposure, animal species used and/or specific compound tested. The studies described herein were undertaken to investigate the immunotoxicity of one member of this family, dimethyldithiocarbamate (DMDTC). We demonstrate that 0.1-0.5 microM DMDTC inhibits TNF-alpha-induced activation of NF-kappaB in primary human CD4+ T cells. This inhibition is not accompanied by a loss in viability, and DMDTC-treated T cells retain other active signaling pathways throughout the exposure duration. The inhibition of NF-kappaB is apparently permanent as DMDTC-treated T cells did not regain normal TNF-alpha activation, even after 72 h in culture. DMDTC does not appear to alter NF-kappaB directly as pre-incubation of nuclear extracts with DMDTC does not diminish binding activity of this protein. We further demonstrate that 0.1-0.5 microM DMDTC inhibits intracellular IL-2 production and decreases surface expression of CD25 (the alpha subunit of the IL-2 receptor) in T cells stimulated with phorbol ester. These data demonstrate that DMDTC is a potent immunosuppressive compound in vitro.

Activation of the human immunodeficiency virus long terminal repeat by varicella-zoster virus IE4 protein requires nuclear factor-kappaB and involves both the amino-terminal and the carboxyl-terminal cysteine-rich region

Varicella-zoster virus open reading frame 4-encoded protein (IE4) possesses transactivating properties for varicella-zoster virus genes as well as for those of heterologous viruses such as the human immunodeficiency virus type 1 (HIV-1). Mechanisms of HIV-1 LTR (long terminal repeat) transactivation were investigated in HeLa cells transiently transfected with an IE4 expression plasmid and a CAT reporter gene under the control of the HIV-1 LTR. These results demonstrated that IE4-mediated transactivation of the HIV-1 LTR in HeLa cells required transcription factor kappaB (NF-kappaB). Using the gel retardation assay, it was shown that transfection of the IE4 expression vector in HeLa cells was not associated with induction of NF-kappaB under the p50.p65 heterodimeric form and that no direct binding of IE4 to the kappaB sites could be detected. Both Western blot and immunofluorescence analyses suggested that the ability of IE4 to activate transcription through kappaB motives was not connected with its capacity to override the inhibitory activities of IkappaB-alpha or p105. Finally, in vitro protein-protein interactions involving IE4 and basal transcription factors such as TATA-binding protein and transcription factor IIB were carried out. A direct interaction between IE4 and TATA-binding protein or transcription factor IIB components of the basal complex of transcription was evidenced, as well as binding to the p50 and p65 NF-kappaB subunits. Mutagenesis analysis of IE4 indicated that the COOH-terminal cysteine-rich and arginine-rich regions (residues 82-182) were critical for transactivation, whereas the first 81 amino acids appeared dispensable. Moreover, the arginine-rich region is required for the in vitro binding activity, whereas the COOH-terminal end did not appear essential.

Hydroquinone, a reactive metabolite of benzene, inhibits NF-kappa B in primary human CD4+ T lymphocytes

Hydroquinone (HQ), a reactive metabolite of benzene, is present in cigarette smoke and is known to inhibit mitogen-stimulated activation of both T and B lymphocytes. Despite extensive study, the underlying mechanism for HQ's immunotoxicity is not clear. NF-kappa B is a transcription factor known to regulate the expression of a number of genes critical for normal T cell activation. We therefore hypothesized that NF-kappa B might be involved in HQ-induced immunosuppression. In this study, we demonstrate that 1 microM HQ inhibits tumor necrosis factor alpha induced activation of NF-kappa B in primary human CD4+ T cells. This inhibition is not accompanied by a loss in viability, and HQ-treated T cells maintain other active signaling pathways throughout the exposure duration. Additionally, the inhibition of NF-kappa B is reversible as HQ-treated T cells regain normal functioning after 72 h in culture. HQ does not appear to alter NF-kappa B directly as preincubation of nuclear extracts with HQ does not diminish activity of this protein. We further demonstrate that 1 microM HQ inhibits intracellular IL-2 production in T cells stimulated with phorbol ester but does not alter surface expression of CD25 (the alpha-subunit of the IL-2 receptor). These data suggest that NF-kappa B may be an important molecular mediator of HQ's (and benzene's) immunotoxicity.

The effects of treatment with chemical agents or infection with feline viruses on protein-binding properties of the feline immunodeficiency virus long terminal repeat

The effects of treatment with chemical agents or infection with feline viruses on protein-binding properties of the feline immunodeficiency virus (FIV) long terminal repeat (LTR) were examined by gel-mobility-shift assays using oligonucleotides designed to represent putative AP-1 or ATF motif from the FIV LTR. Infection with FIV led to less nuclear proteins binding to the AP-1 and ATF sites, suggesting that proteins binding to the sites were consumed or suppressed by FIV-replication in FIV-infected cells. Nuclear proteins that bind to the AP-1 or ATF site were examined by using extracts from Crandell feline kidney (CRFK) cells treated with TPA (a phorbol ester; a strong activator of protein kinase C) or forskolin (an inducer of cyclic-AMP), or infection with feline herpesvirus type 1 (FHV-1). Although TPA or forskolin treatment moderately increased the level of both proteins that bound to AP-1 and ATF sites, FHV-1 infection markedly changed the protein-binding patterns of the sites. Furthermore, FHV-1-induced proteins that bind adjacent to the transcriptional initiation site of FIV promoter were also observed in FHV-1-infected CRFK cells, suggesting that the FHV-1-induced-proteins affects the transcription of FIV through the AP-1, ATF and leader sequences.

A human B-lymphoblastoid cell line constitutively producing Epstein-Barr herpesvirus and JHK retrovirus

The human B-lymphoblastoid cell line, designated JHK-3, with pre-B-cell characteristics, chronically produces two viruses, Epstein-Barr virus (EBV) and JHK virus, an apparently novel retrovirus. The JHK-3 cells are much more productive of extracellular EBV than the high-producer marmoset line B95-8. The extracellular virus of the JHK-3 EBV strain is relatively fragile, more broadly dispersed in an ultracentrifuged sucrose gradient than the B95-8 EBV and more susceptible to disruption by combined treatment with urea and dithiothreitol. By restriction fragment length polymorphism analysis, the JHK-3 EBV strain resembles the EBV strain FF-41. The JHK-3 cells also produce an incompletely characterized, relatively fragile, enveloped, icosahedral RNA virus that contains Mn(++)-dependent reverse transcriptase. JHK virions measure 85 nm in ultrathin sections, much smaller than other Retroviridae. The JHK virus exhibits a distinctive morphogenesis, most nearly resembling C-type retroviruses. The JHK-3 cell line provides a human cell model for investigating virus/virus interactions and their pathogenetic affects on host cells which chronically and simultaneously produce DNA and RNA viruses.

Construction and characterization of a recombinant herpes simplex virus type 1 which overexpresses the transrepressor protein ICPOR

ICPOR is a truncated form of the herpes simplex virus type 1 (HSV-1) transactivator protein ICPO that is synthesized at low levels during infection through an alternative splicing mechanism. In transient expression assays, ICPOR has been shown to inhibit the transactivation function of several HSV-1 regulatory proteins, suggesting that an antiviral strategy which alters normal ICPO mRNA splicing and thereby stimulates the synthesis of ICPOR protein may have potential in suppressing HSV-1 infections. To explore the feasibility of this approach, a recombinant virus was constructed which expressed high levels of ICPOR instead of ICPO. Surprisingly, overexpression of the ICPOR protein in this virus, HSV-KST, had no detectable effect on virus replication, since the growth properties of HSV-KST were indistinguishable from those of the ICPO/ICPOR null mutant dl 1403, and HSV-KST was no more efficient than dl 1403 at inhibiting the replication of an ICPO-expressing wild-type virus. The absence of a demonstrable phenotype in HSV-KST was not due to the acquisition of an inactivating mutation in the gene encoding ICPOR, since copies of the gene rescued from this virus retained full transrepression capability in transient expression assays. These results indicate that the ability of ICPOR to act as a transrepressor is significantly reduced if not completely eliminated in the context of a productive HSV-1 infection and suggest that this protein may not represent an exploitable target for the development of novel antiviral therapies.

Mutational analysis of ICP0R, a transrepressor protein created by alternative splicing of the ICP0 gene of herpes simplex virus type 1

The immediate-early protein ICP0 (infected-cell polypeptide 0) of herpes simplex virus type 1 (HSV-1) is a promiscuous transactivator of both viral and nonviral promoters in transient expression assays. Failure to splice the second of two introns in the ICP0 gene results in the utilization of an alternate stop codon that generates a truncated form of ICP0 called ICP0R. This protein exists in low levels in HSV-1-infected cells and functions as a dominant negative repressor of ICP0-mediated transactivation in transient expression assays. To conduct a detailed structure-function analysis of ICP0R, a series of insertion and deletion mutants of this protein were generated and analyzed in transfection assays. These studies indicated that segments of ICP0R that were rich in acidic amino acid residues (amino acids 9 to 76 and 233 to 241) or glycine residues (amino acids 242 to 262) were dispensable for the dominant negative phenotype. In contrast, the RING finger domain (amino acids 116 to 156) and surprisingly the sequences carboxy terminal to it (amino acids 157 to 232) were absolutely essential for transdominant repression. Consistent with these findings, the amino acid sequences of these two regions were conserved among other alphaherpesvirus ICP0 homologs. A construct containing only amino acids 76 to 232 inhibited ICP0-mediated transactivation almost as efficiently as wild-type ICP0R and represented the minimal sequences necessary for the dominant negative phenotype. These results demonstrated that the critical functional domain shared by both ICP0R and ICP0 is much more complex than a simple RING finger motif. Western blot (immunoblot) analyses of transfected cell lysates revealed that nearly all of the mutant constructs directed the expression of stable ICP0R proteins of the predicted molecular weight. However, there was a striking inverse correlation between the ability of a mutant construct to mediate transrepression and the amount of protein that it synthesized, indicating that dominant negative inhibition is achieved through the action of very little ICP0R protein.

Cooperation between herpes simplex virus type 1-encoded ICP0 and Tat to support transcription of human immunodeficiency virus type 1 long terminal repeat in vivo can occur in the absence of the TAR binding site

Expression of human immunodeficiency virus type 1 (HIV-1) provirus can be stimulated by herpes simplex virus type 1 (HSV-1) infection; the stimulation occurs at the level of transcriptional activation of the HIV long terminal repeat (LTR) and is mediated by both cellular and HSV-1-encoded transactivators. We have shown in this study that HSV-1 immediate-early gene ICP0 cooperates effectively with the HIV-1-encoded transactivator, Tat, in the stimulation of HIV-1 LTR-directed transcription. The cooperation between ICP0 and Tat is specific for the HIV-1 LTR and was not observed with other promoters (e.g., ICP0) that can be transactivated by ICP0 but not by Tat. Analyses of HIV-1 LTR deletion mutants have shown that ICP0 not only transactivates an HIV-1 LTR mutant that is unresponsive to NF-kappaB and Tat-mediated transactivation, such as the HIV-1 LTR with the enhancer deleted (-83 LTR) and TAR deleted (+20 to +81), but also restores responsiveness to Tat. ICP0 also showed cooperation with Gal4-Tat fusion protein-mediated transactivation of Gal4-HIV-1 LTR with TAR deleted. Enhancement of the transcriptional activation of ICP0 by Tat requires both the cysteine-rich and core domains of Tat and is inhibited by RO5-3335. ICP0 stimulates transcription of not only the HIV-1 LTR but also the TAR-defective HIV-1 provirus. We suggest that ICP0 can (i) recruit Tat to the vicinity of the HIV-1 promoter, thereby providing an alternative binding site for Tat, and (ii) substitute for the enhancer-binding proteins that are required for efficient Tat transactivation in T cells.

Human immunodeficiency virus tat gene transfer to the murine central nervous system using a replication-defective herpes simplex virus vector stimulates transforming growth factor beta 1 gene expression

The high incidence of neurological disorders in patients afflicted with acquired immunodeficiency syndrome (AIDS) may result from human immunodeficiency virus type 1 (HIV-1) induction of chemotactic signals and cytokines within the brain by virus-encoded gene products. Transforming growth factor beta1 (TGF-beta1) is an immunomodulator and potent chemotactic molecule present at elevated levels in HIV-1-infected patients, and its expression may thus be induced by viral trans-activating proteins such as Tat. In this report, a replication-defective herpes simplex virus (HSV)-1 tat gene transfer vector, dSTat, was used to transiently express HIV-1 Tat in glial cells in culture and following intracerebral inoculation in mouse brain in order to directly determine whether Tat can increase TGF-beta1 mRNA expression. dSTat infection of Vero cells transiently transfected by a panel of HIV-1 long terminal repeat deletion mutants linked to the bacterial chloramphenicol acetyltransferase reporter gene demonstrated that vector-expressed Tat activated the long terminal repeat in a trans-activation response element-dependent fashion independent of the HSV-mediated induction of the HIV-1 enhancer, or NF-kappaB domain. Northern blot analysis of human astrocytic glial U87-MG cells transfected by dSTat vector DNA resulted in a substantial increase in steady-state levels of TGF-beta1 mRNA. Furthermore, intracerebral inoculation of dSTat followed by Northern blot analysis of whole mouse brain RNA revealed an increase in levels of TGF-beta1 mRNA similar to that observed in cultured glial cells transfected by dSTat DNA. These results provided direct in vivo evidence for the involvement of HIV-1 Tat in activation of TGF-beta1 gene expression in brain. Tat-mediated stimulation of TGF-beta1 expression suggests a novel pathway by which HIV-1 may alter the expression of cytokines in the central nervous system, potentially contributing to the development of AIDS-associated neurological disease.

Herpes simplex virus-mediated activation of human immunodeficiency virus is inhibited by oligonucleoside methylphosphonates that target immediate-early mRNAs 1 and 3

IE1 and IE3 mRNAs and their protein products (IE110 and IE175, respectively) were detected in HSV-1-infected U937 cells at 4-15 hours postinfection. In transient expression assays with infectious HIV or an HIV-LTR-directed chloramphenicol acetyltransferase construction (HIV-LTRcat), HSV-1 caused HIV activation (86.7% +/- 6.4% conversion). Electrophoretic mobility shift assays with DNA sequences that encompass the LBP-1 binding site revealed increased levels of DNA-protein complex formation with nuclear extracts from HSV-1 infected as compared with uninfected U937 cells. Novel bands were not seen. HSV-1 mutants respectively deleted in IE110 (dl1403) or IE175 (d120) activated HIV as well as wild-type virus. However, HSV-1-mediated activation was inhibited (26% conversion) by simultaneous treatment with oligonucleoside methylphosphonates (ONMP) that specifically inhibit expression of IE110 (IE1TI) or IE175 (IE3TI). ONMP did not inhibit activation when used individually (83.8% and 67.8% conversion with IETI1 and IE3TI, respectively). Combinations of mutant ONMP that do not inhibit IE110 or IE175 expression did not reduce the levels of HSV-1-mediated activation. These findings suggest that HSV genes IE1 and IE3 can independently activate HIV in monocytic cells and ONMP that target HSV IE genes can be used to inhibit HIV activation.

Regulation of human immunodeficiency virus type 1 and cytokine gene expression in myeloid cells by NF-kappa B/Rel transcription factors

CD4+ macrophages in tissues such as lung, skin, and lymph nodes, promyelocytic cells in bone marrow, and peripheral blood monocytes serve as important targets and reservoirs for human immunodeficiency virus type 1 (HIV-1) replication. HIV-1-infected myeloid cells are often diminished in their ability to participate in chemotaxis, phagocytosis, and intracellular killing. HIV-1 infection of myeloid cells can lead to the expression of surface receptors associated with cellular activation and/or differentiation that increase the responsiveness of these cells to cytokines secreted by neighboring cells as well as to bacteria or other pathogens. Enhancement of HIV-1 replication is related in part to increased DNA-binding activity of cellular transcription factors such as NF-kappa B. NF-kappa B binds to the HIV-1 enhancer region of the long terminal repeat and contributes to the inducibility of HIV-1 gene expression in response to multiple activating agents. Phosphorylation and degradation of the cytoplasmic inhibitor I kappa B alpha are crucial regulatory events in the activation of NF-kappa B DNA-binding activity. Both N- and C-terminal residues of I kappa B alpha are required for inducer-mediated degradation. Chronic HIV-1 infection of myeloid cells leads to constitutive NF-kappa B DNA-binding activity and provides an intranuclear environment capable of perpetuating HIV-1 replication. Increased intracellular stores of latent NF-kappa B may also result in rapid inducibility of NF-kappa B-dependent cytokine gene expression. In response to secondary pathogenic infections or antigenic challenge, cytokine gene expression is rapidly induced, enhanced, and sustained over prolonged periods in HIV-1-infected myeloid cells compared with uninfected cells. Elevated levels of several inflammatory cytokines have been detected in the sera of HIV-1-infected individuals. Secretion of myeloid cell-derived cytokines may both increase virus production and contribute to AIDS-associated disorders.

Association between HIV and other DNA viruses in vitro

To investigate the association of human immunodeficiency virus (HIV) with various DNA viruses, including hepatitis B virus (HBV), cytomegalovirus (CMV) and Epstein-Barr virus, (EBV), simultaneous detection of HIV p24 antigen, HBV surface antigen and DNA, CMV-DNA and EBV-DNA expression was performed in phytohemagglutinin-stimulated peripheral blood mononuclear (PBMC) culture supernatants obtained from 54 individuals at risk for HIV infection. HIV expression in PBMC culture supernatants never occurred alone; expression of other viruses was always detected in the 24 samples expressing HIV antigen in vitro. Furthermore, in 16 patients expression of other viruses was detected without HIV expression, and in 14 patients none of the tested viruses were detected. These results indicate a strong association between the presence of HIV antibody and expression of DNA viruses in vitro (p = 0.0001). The coexpression of these viruses could be related to the evolution of HIV infection and AIDS.

Residual expression of reporter genes in constructs mimicking HIV genome organization

Plasmids were constructed whereby the expression of a reporter gene, either the cDNA corresponding to the secreted form of human alkaline phosphatase (SEAP) or the herpes simplex virus type 1 (HSV1) thymidine kinase (tk) gene, was rendered dependent upon the expression of the human immunodeficiency virus type 1 (HIV1) tat and rev proteins. The SEAP or tk genes were placed between HIV1 splice donor and acceptor sites. One SEAP construct carried a series of alternating splice donor and acceptor sites. In all cases, the rev response element mapped within an intron. Despite such mimicry of the HIV1 genome, residual expression of the reporter gene in the absence of tat and rev was observed. These results, as well as non-specific T-cell recruitment, suggest limits to the specificity of using HIV-activated toxic gene expression to kill HIV-infected cells.

Transactivation of human T-cell leukemia virus type 1 by herpes simplex virus type 1

HTLV-1 transcription depends upon activation by the HTLV-1 tax gene product. In addition, various substances and cellular transcription factors are also known to activate the HTLV-1 long terminal repeat (LTR)-mediated transcription in the absence of Tax. In this work we demonstrate that infection of either Jurkat or 293 cell lines with herpes simplex I (HSV-1), a widespread infectious virus of humans, activates HTLV-1 LTR-mediated gene expression. Further investigation revealed that each of the immediate-early (IE) gene products--ICPO, ICP4, and ICP27--of HSV-1 transactivates the HTLV-1 LTR-mediated gene expression in the absence of Tax. The HSV-1 activation is additive to Tax activation in its presence in the cell. Three 21 base repeats upstream of the TATA box are known as the TAX responsive elements (TRE). Recombinant HTLV-1 minimal promoter composed of the HTLV-1 TATA box fused to a synthetic 21 base TRE is responsive to Tax but not to HSV-1 activation. It thus can be concluded that HSV-1 IE gene products and Tax transactivates HTLV-1 LTR mediated gene expression through different transcription complexes. The results presented in this work may point to one possible way for the transition of HTLV-1 from a quiescent to an actively replicating stage.

AAV as a viral vector for human gene therapy. Generation of recombinant virus

Investigation of the adeno-associated virus (AAV) life cycle has enabled the establishment of methodology and identification of critical cis-acting sequences required for recombinant AAV production. Vectors derived from the defective human parvovirus (AAV) have been used for successful gene transfer and expression in many diverse mammalian cell types, such as erythroid, airway epithelium, and neuronal cells. One of the crucial steps in the continued case of AAV as a vector is the development of packaging systems that will allow efficient encapsidation of foreign genes into AAV virions. For this reason, the focus of this article will be generation of recombinant AAV vectors.

Herpes-Simplex-Virus-Infected Cells Produce a Protein that Binds to the TAR DNA Region of the Human Immunodeficiency Virus Type 1 Long Terminal Repeat

Activation of human immunodeficiency virus type 1 (HIV-1) provirus by herpes simplex virus type 1 (HSV-1) infection is mediated by both HSV-1 gene products and cellular transactivators. Previously, several key factors such as NF-kappaB-specific proteins p55 and p85, HLP-1 protein that binds to the LBP-1 sequences of the HIV-1 long terminal repeat (LTR) and the viral transactivator ICPO were found to play a role in the transcriptional activation of HIV-1 LTR expression. In this report, we describe binding of herpesvirus-specific protein TDP150 to the TAR DNA region of the HIV-1 LTR. Our data suggest that TDP150 may be related to the herpesvirus transactivator protein ICP4; both proteins are 150-kD DNA-binding proteins produced in HSV-infected cells in the presence of an inhibitor of viral DNA replication. However, the appearance of TDP150-binding activity is delayed by several hours compared to that of ICP4 and the DNA-binding specificity of TDP150 differs from that of purified ICP4. These results suggest that TDP150 is not identical to ICP4; whether it is its analogue remains to be determined. TAR DNA alone can confer responsiveness of heterologous promoter to HSV-1 infection, suggesting that this region can function as an enhancer in HSV-1-infected cells. Deletion of the TAR region from the HIV-1 LTR has not changed significantly the HSV-1-mediated stimulation. Copyright 1994 S. Karger AG, Basel