Activation of human immunodeficiency virus by herpesvirus infection: identification of a region within the long terminal repeat that responds to a trans-acting factor encoded by herpes simplex virus 1

Functionalized Noble Metal Nanoparticles for the Treatment of Herpesvirus Infection

Neuroinfections caused by herpesviruses, mainly by HHV-1, represent a significant problem for modern medicine due to the small number of therapeutic substances available in the pharmaceutical sector. Furthermore, HHV-1 infection has been linked to neurodegenerative processes such as Alzheimer’s disease, which justifies the search for new effective therapies. The development of nanotechnology opens up new possibilities for the treatment of neuroinflammation. Gold and silver nanoparticles are gaining popularity, and the number of clinical trials involving metallic nanoparticles is constantly increasing. This paper reviews the research on gold and silver nanoparticles and their potential use in the treatment of herpesvirus neuroinfection.

"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.

Reducing Risk: Counseling Men Infected with HIV Who Have Sex with Men on Safer Sex Practices with Seroconcordant Partners

The incidence of new HIV infections in the United States continues to be greatest among men who have sex with men (MSM). MSM infected with HIV often seek seroconcordant sexual partners based on intent to limit psychosocial, legal, and health risks they perceive as higher with serodiscordant sexual partners. However, the rationales for limiting sexual relationships exclusively with other MSM infected with HIV may be rooted in misinformation or misperception. Thus, these clients may have a unique sexual health knowledge deficit that nurses, social workers, and other clinicians need to address to help them reduce risk. This article focuses on sexually related health risks that are distinct to MSM infected with HIV seroconcordant partners. Data on the most recent HIV-infection incidence rates in MSM in the United States is provided. Discussion concentrates on the risk these individuals may have in communicating and acquiring sexually transmitted diseases other than HIV, the risk of HIV superinfection, and how sexually transmitted diseases affect persons who are immunocompromised differently than those who are immunocompetent. Finally, recommendations for healthcare professionals who counsel MSM infected with HIV in sexual decision making is provided.

Absence of interaction between porcine endogenous retrovirus and porcine cytomegalovirus in pig-to-baboon renal xenotransplantation in vivo

BACKGROUND

Studies of xenotransplantation from swine have identified porcine viruses as potential barriers to clinical trials. The biology of these viruses has not been extensively investigated in the in vivo xeno-environment. Enhancement of viral gene expression by viral and cellular factors acting in trans has been demonstrated for certain viruses, including bidirectional interactions between human herpesviruses and endogenous (HERV) and exogenous (HIV) retroviruses. Both porcine cytomegalovirus (PCMV) and porcine endogenous retrovirus (PERV) infections have been identified in xenografts from swine. PERV receptors exist on human cells with productive infection in vitro in permissive human target cell lines. PCMV is largely species-specific with infection restricted to the xenograft in pig-to-baboon transplants. It is unknown whether coinfection by PCMV affects the replication of PERV within xenograft tissues which might have implications for the risk of retroviral infection in the human host.

METHODS

A series of 11 functioning, life-supporting pig-to-baboon kidney xenografts from PERV-positive miniature swine were studied with and without PCMV co-infection. Frozen biopsy samples were analyzed using quantitative, real-time PCR with internal controls.

RESULTS

PERV replication was not altered in the presence of PCMV coinfection (P = .70). The absence of variation with coinfection was confirmed when PERV quantitation was expressed relative to simultaneous cellular GAPDH levels with or without PCMV coinfection (P = .59).

CONCLUSIONS

PCMV coinfection does not alter the replication of PERV in life-supporting renal xenotransplantation in vivo in baboons.

Analysis of Select Herpes Simplex Virus 1 (HSV-1) Proteins for Restriction of Human Immunodeficiency Virus Type 1 (HIV-1): HSV-1 gM Protein Potently Restricts HIV-1 by Preventing Intracellular Transport and Processing of Env gp160

Virus-encoded proteins that impair or shut down specific host cell functions during replication can be used as probes to identify potential proteins/pathways used in the replication of viruses from other families. We screened nine proteins from herpes simplex virus 1 (HSV-1) for the ability to enhance or restrict human immunodeficiency virus type 1 (HIV-1) replication. We show that several HSV-1 proteins (glycoprotein M [gM], US3, and UL24) potently restricted the replication of HIV-1. Unlike UL24 and US3, which reduced viral protein synthesis, we observed that gM restriction of HIV-1 occurred through interference with the processing and transport of gp160, resulting in a significantly reduced level of mature gp120/gp41 released from cells. Finally, we show that an HSV-1 gM mutant lacking the majority of the C-terminal domain (HA-gM[Δ345-473]) restricted neither gp160 processing nor the release of infectious virus. These studies identify proteins from heterologous viruses that can restrict viruses through novel pathways.IMPORTANCE HIV-1 infection of humans results in AIDS, characterized by the loss of CD4⁺ T cells and increased susceptibility to opportunistic infections. Both HIV-1 and HSV-1 can infect astrocytes and microglia of the central nervous system (CNS). Thus, the identification of HSV-1 proteins that directly restrict HIV-1 or interfere with pathways required for HIV-1 replication could lead to novel antiretroviral strategies. The results of this study show that select viral proteins from HSV-1 can potently restrict HIV-1. Further, our results indicate that the gM protein of HSV-1 restricts HIV-1 through a novel pathway by interfering with the processing of gp160 and its incorporation into virus maturing from the cell.

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.

Exploitation of a Rapid and Sensitive Assay to Analyse Transactivation of the Human Immunodeficiency Virus type 1 (HIV-1) Long Terminal Repeat

Transregulation of the promoter within the 5′ long terminal repeat (LTR) of the human immunodeficiency virus (HIV) provirus determines the level of replication of HIV in latently, persistently or acutely infected cells. To measure rapidly the degree of transactivation of the HIV-1 LTR by various cellular and viral effectors, stably transformed cell lines containing integrated copies of the HIV LTR promoter (−122 to +80, relative to the major mRNA cap site) linked to the Escherichia coli lac Z gene were prepared by co-selection for pSV2 neo-mediated G418 resistance. One cell clone, RS 3/7, containing about 40 integrated copies of the recombinant LTR- lacZ gene was analysed further. RS 3/7 cells expressed high levels of β-galactosidase in response to co-transfection with plasmids expressing the HIV-1 transactivator, tat, infection with low multiplicities of herpes simplex virus type 1 (HSV-1), transfection with a plasmid expressing the HSV-1 immediate-early (IE) protein, ICPO, and by incubation with medium containing sodium butyrate. β-galactosidase activity was also induced by incubation of RS 3/7 cells with medium containing full length tat polypeptide. The cysteine analogue, D-penicillamine, previously reported as a potent inhibitor of tat-mediated transactivation (Chandra et al., 1988), was of limited efficacy in RS 3/7 cells transfected with tat-expressing plasmids. This cell line will be of value in identifying additional transactivators of the HIV-1 LTR, and in the selection of inhibitors of such effectors.

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.

Herpes simplex virus type 2-infected dendritic cells produce TNF-α, which enhances CCR5 expression and stimulates HIV production from adjacent infected cells

Prior HSV-2 infection enhances the acquisition of HIV-1 >3-fold. In genital herpes lesions, the superficial layers of stratified squamous epithelium are disrupted, allowing easier access of HIV-1 to Langerhans cells (LC) in the epidermis and perhaps even dendritic cells (DCs) in the outer dermis, as well as to lesion infiltrating activated T lymphocytes and macrophages. Therefore, we examined the effects of coinfection with HIV-1 and HSV-2 on monocyte-derived DCs (MDDC). With simultaneous coinfection, HSV-2 significantly stimulated HIV-1 DNA production 5-fold compared with HIV-1 infection alone. Because <1% of cells were dually infected, this was a field effect. Virus-stripped supernatants from HSV-2-infected MDDCs were shown to enhance HIV-1 infection, as measured by HIV-1-DNA and p24 Ag in MDDCs. Furthermore these supernatants markedly stimulated CCR5 expression on both MDDCs and LCs. TNF-α was by far the most prominent cytokine in the supernatant and also within HSV-2-infected MDDCs. HSV-2 infection of isolated immature epidermal LCs, but not keratinocytes, also produced TNF-α (and low levels of IFN-β). Neutralizing Ab to TNF-α and its receptor, TNF-R1, on MDDCs markedly inhibited the CCR5-stimulating effect of the supernatant. Therefore, these results suggest that HSV-2 infection of DCs in the skin during primary or recurrent genital herpes may enhance HIV-1 infection of adjacent DCs, thus contributing to acquisition of HIV-1 through herpetic lesions.

Impact of HIV-1 infection on herpes simplex virus type 2 genetic variability among co-infected individuals

Herpes simplex virus type 2 (HSV-2) is the most common cause of genital ulcer disease worldwide. While the contribution of HSV-2 to acquisition and course of human immunodeficiency virus (HIV) infection has been well described, less attention has been paid to the impact of HIV infection on the variability and the pathophysiology of HSV-2 infection. The goal of the present study was to characterize genotypically and phenotypically HSV-2 strains isolated from 12 patients infected by HIV-1 and from 12 HIV-negative patients. Replication capacity analyses were carried out in Vero cells and full-length nucleotide sequences were determined for glycoproteins B (gB), D (gD), G (gG), thymidine kinase (TK), and DNA polymerase (POL) HSV-2 genes. Sequence alignments and phylogenetic trees were performed. No significant differences were found in terms of replication capacity. The interstrain nucleotide identities of the 3 glycoprotein genes (gB, gC, and gG) ranged from 99.5% to 100% among the 24 HSV-2 strains. The phylogenetic analysis showed no clustering of HSV-2 strains when correlating to the HIV status of the patients. A lower variability was observed for the functional proteins TK and DNA polymerase (98.9% to 100% identity). Genetic analysis of TK evidenced mutations related to acyclovir-resistance in two HSV-2 strains. No specific differences regarding replication capacity and gene sequence were found when comparing HSV-2 strains isolated from patients infected with HIV-1 and HIV-negative patients, suggesting that the virological properties of HSV-2 infection are not influenced by HIV-1 infection among co-infected patients.

The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs.

Effect of genital herpes on cervicovaginal HIV shedding in women co-infected with HIV AND HSV-2 in Tanzania

OBJECTIVES

To compare the presence and quantity of cervicovaginal HIV among HIV seropositive women with clinical herpes, subclinical HSV-2 infection and without HSV-2 infection respectively; to evaluate the association between cervicovaginal HIV and HSV shedding; and identify factors associated with quantity of cervicovaginal HIV.

DESIGN

Four groups of HIV seropositive adult female barworkers were identified and examined at three-monthly intervals between October 2000 and March 2003 in Mbeya, Tanzania: (1) 57 women at 70 clinic visits with clinical genital herpes; (2) 39 of the same women at 46 clinic visits when asymptomatic; (3) 55 HSV-2 seropositive women at 60 clinic visits who were never observed with herpetic lesions; (4) 18 HSV-2 seronegative women at 45 clinic visits. Associations of genital HIV shedding with HIV plasma viral load (PVL), herpetic lesions, HSV shedding and other factors were examined.

RESULTS

Prevalence of detectable genital HIV RNA varied from 73% in HSV-2 seronegative women to 94% in women with herpetic lesions (geometric means 1634 vs 3339 copies/ml, p = 0.03). In paired specimens from HSV-2 positive women, genital HIV viral shedding was similar during symptomatic and asymptomatic visits. On multivariate regression, genital HIV RNA (log10 copies/mL) was closely associated with HIV PVL (β = 0.51 per log10 copies/ml increase, 95%CI:0.41-0.60, p<0.001) and HSV shedding (β = 0.24 per log10 copies/ml increase, 95% CI:0.16-0.32, p<0.001) but not the presence of herpetic lesions (β = -0.10, 95%CI:-0.28-0.08, p = 0.27).

CONCLUSIONS

HIV PVL and HSV shedding were more important determinants of genital HIV than the presence of herpetic lesions. These data support a role of HSV-2 infection in enhancing HIV transmissibility.

Immune modulation during latent herpesvirus infection

Nearly all human beings, by the time they reach adolescence, are infected with multiple herpesviruses. At any given time, this family of viruses accounts for 35-40 billion human infections worldwide, making herpesviruses among the most prevalent pathogens known to exist. Compared to most other viruses, herpesviruses are also unique in that infection lasts the life of the host. Remarkably, despite their prevalence and persistence, little is known about how these viruses interact with their hosts, especially during the clinically asymptomatic phase of infection referred to as latency. This review explores data in human and animal systems that reveal the ability of latent herpesviruses to modulate the immune response to self and environmental antigens. From the perspective of the host, there are both potentially detrimental and surprisingly beneficial effects of this lifelong interaction. The realization that latent herpesvirus infection modulates immune responses in asymptomatic hosts forces us to reconsider what constitutes a 'normal' immune system in a healthy individual.

Mechanisms of viral infections associated with HIV: workshop 2B

HIV infection is commonly associated with activation and dissemination of several other viral pathogens, including herpes simplex virus 1/2, human cytomegalovirus, human herpesvirus 8, Epstein-Barr virus, Varicella Zoster virus, and human papillomavirus, which behave as opportunistic agents and cause various diseases in immunocompromised hosts. The increased frequency and severity of diseases caused by these viruses in HIV-infected individuals is due mainly to dysfunction of both the adaptive and innate immune responses to viral pathogens. In addition, molecular interactions between HIV and these opportunistic viruses are likely to play critical roles in the progression of disease, including neoplasia. This report reviews the critical aspects of HIV interaction with opportunistic viruses, including Epstein-Barr virus, human cytomegalovirus, herpes simplex virus, Varicella Zoster virus, human herpesvirus 8, and human papillomavirus.

Consistent inhibition of HIV-1 replication in CD4+ T cells by acyclovir without detection of human herpesviruses

Acyclovir, a nucleoside analog, is thought to be specific for the human herpesviruses because it requires a virally encoded enzyme to phosphorylate it to acyclovir monophosphate. Recently, acyclovir triphosphate was shown to be a direct inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. Here, we showed that acyclovir is an inhibitor of HIV-1 replication in CD4(+) T cells from cord blood that have undetectable levels of the eight human herpesviruses. Additionally, acyclovir phosphates were detected by reverse-phase-high performance liquid chromatography (RP-HPLC) and quantified in a primer extension assay from cord blood. The data support acyclovir as an inhibitor of HIV-1 replication in herpesvirus-negative cells.

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.

Herpes simplex virus type 2 enhances HIV-1 susceptibility by affecting Langerhans cell function

Genital herpes is the most prevalent viral sexually transmitted infection worldwide and is mainly caused by HSV type 2 (HSV-2). HSV-2 infection enhances HIV-1 susceptibility, even in the absence of clinical symptoms. In this study, we investigated the effect of HSV-2 on HIV-1 transmission by mucosal Langerhans cells (LCs). LCs are important in heterosexual transmission because they form a barrier against HIV-1 infection; LCs efficiently capture and degrade HIV-1 through the C-type lectin langerin, thereby preventing HIV-1 transmission. Notably, our data showed that HSV-2 enhanced HIV-1 infection of LCs and subsequent HIV-1 transmission to T cells. HSV-2 interfered with HIV-1 capture by langerin, which allowed efficient HIV-1 infection of LCs. HSV-2 inhibited the antiviral function of langerin at two levels; HSV-2 decreased langerin expression and competed with HIV-1 for langerin binding. HSV-2 replication was not required, because both UV-inactivated HSV-2 and TLR-3 agonist polyinosinic:polycytidylic acid similarly increased HIV-1 transmission by LCs. Therefore, we identified a mechanism by which HSV-2 enhances HIV-1 susceptibility, even in the absence of clinical symptoms. Our data demonstrated that viral coinfections, such as HSV-2, breach the protective function of LCs by abrogating langerin function, which increases HIV-1 susceptibility. These data reinforce the importance of preventing sexually transmitted infections, such as HSV-2, to reduce the transmission of HIV-1.

Long-term impact of acyclovir suppressive therapy on genital and plasma HIV RNA in Tanzanian women: a randomized controlled trial

BACKGROUND

Herpes simplex virus (HSV) suppressive therapy reduces genital and plasma human immunodeficiency virus type 1 (HIV-1) RNA over periods up to 3 months, but the long-term effect is unknown.

METHODS

A total of 484 HIV-1 and HSV type 2 seropositive Tanzanian women aged 16-35 years were enrolled in a randomized placebo-controlled trial of acyclovir administered at a dosage of 400 mg twice daily. Cervico-vaginal lavage and blood samples were collected at 6 months, 12 months, and 24 months for quantification of genital and plasma HIV-1 RNA and genital HSV DNA. Primary outcomes were detection and quantity of cervico-vaginal HIV-1 RNA at 6 months.

RESULTS

At 6 months, there was little difference between the acyclovir and placebo arms for cervico-vaginal HIV-1 RNA detection (88 [ 41 .3%] of 213 vs 84 [ 44 .0%] of 191; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.60-1.33), HSV DNA detection (20 [ 9 .4%] of 213 vs 22 [ 11 .5%] of 191; OR, 0.80; 95% CI, 0.42-1.51), genital HIV or HSV loads, or plasma HIV-1 RNA load. Estimated median adherence was 91%. There was a suggestion of an impact on cervico-vaginal HIV-1 RNA detection among women with estimated adherence 90% (OR, 0.74; 95% CI, 0.50-1.09) when data from all 3 visits were included.

CONCLUSIONS

Acyclovir administered at a dosage of 400 mg twice daily is unlikely to be a useful long-term intervention to reduce HIV transmission. The lack of effect on HIV may be attributable to suboptimal adherence or treatment regimen.

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.

A flow cytometric assay for the study of E3 ubiquitin ligase activity

Current methods for monitoring E3 ubiquitin ligase activity in cell culture or in vivo are limited. As a result, the degradation of cellular targets by many E3 ubiquitin ligases in live cells has not yet been examined. For this study, a target of an E3 ubiquitin ligase was expressed as a fluorescently labeled protein in cell culture. If the E3 ubiquitin ligase mediates the degradation of a target protein in cell culture, it is expected that the target will show a reduced fluorescence signal by FCM analysis. We initially used the E3 ubiquitin ligase, herpes simplex virus type 1 (HSV-1) infected cell protein 0 (ICP0) and one of its targets, promyelocytic leukemia (PML) protein, to determine the feasibility of our approach. Cells expressing a PML-GFP fusion protein were selected by cell sorting and infected with an adenoviral vector expressing ICP0. In contrast to mock-infected cells, only PML-GFP-expressing cells infected with the ICP0 adenoviral vector led to a significant decrease in the fluorescence signal of PML-GFP when examined by fluorescence microscopy and FCM analysis. Our results suggest that it is possible to examine the live activity of an E3 ubiquitin ligase (via one of its targets) in cell culture by FCM analysis.

An African perspective on mucosal immunity and HIV-1

HIV prevention mandates an understanding of the mechanisms of mucosal immunity with attention to some unique features of the epidemic and mucosal environment in the developing world. An effective vaccine will have to induce mucosal protection against a highly diverse virus, which is equipped with a number of immune evasion strategies. Its development will require assessment of mucosal immune responses, and it will have to protect a mucosal environment where inflammation and altered immune responses are common because of the presence of other mucosal infections, such as sexually transmitted infections and parasites, and where nutritional status may also be compromised. Ideally, not only prevention methods would protect adults but also provide cover against gastrointestinal transmission through maternal milk. Prevention might also be complemented by microbicides and circumcision, two alternative approaches to mucosal protection. It seems unlikely that a single solution will work in all instances and intervention might have to act at multiple levels and be tailored to local circumstances. We review here some of the mucosal events associated with HIV infection that are most relevant in an African setting.

The antiherpetic drug acyclovir inhibits HIV replication and selects the V75I reverse transcriptase multidrug resistance mutation

The antiviral drug acyclovir is a guanosine nucleoside analog that potently inhibits herpes simplex virus (HSV) replication. Acyclovir treatment in patients coinfected with HSV and human immunodeficiency virus (HIV) has been observed to alter disease course and decrease HIV viral load, a finding that has been attributed to indirect effects of HSV suppression on HIV replication. Based on this hypothesis, several clinical studies have recently investigated the use of acyclovir for treatment of patients coinfected with HSV and HIV or for prophylaxis against HIV transmission. In this report, we use a single round HIV infectivity assay to show that acyclovir directly inhibits HIV infection with an IC50 of approximately 5 microm. The target of acyclovir in HIV-infected cells is validated as HIV reverse transcriptase (RT) by the emergence of the RT variant V75I under the selective pressure of acyclovir. The V75I mutation is part of the multidrug resistance pathway that enhances viral resistance to many of the best RT inhibitors approved for the treatment of HIV. Biochemical analyses demonstrate that acyclovir triphosphate is a chain terminator substrate for HIV RT and can compete with dGTP for incorporation into DNA. Although acyclovir may prove a useful lead for development of new HIV treatments, the selection of resistant mutants raises a cautionary note to the use of acyclovir monotherapy in patients coinfected with HSV and HIV.

Induction of cellular stress overcomes the requirement of herpes simplex virus type 1 for immediate-early protein ICP0 and reactivates expression from quiescent viral genomes

Herpes simplex virus type 1 (HSV-1) mutants impaired in the activities of the structural protein VP16 and the immediate-early (IE) proteins ICP0 and ICP4 establish a quiescent infection in human fibroblasts, with most cells retaining an inactive, repressed viral genome for sustained periods in culture. To date, the quiescent state has been considered stable, since it has been reversed only by provision of herpesviral proteins, such as ICP0, not by alteration of the cell physiological state. We report that the interaction of HSV-1 with human fibroblasts can be altered significantly by transient treatment of cultures with sodium arsenite, an inducer of heat shock and oxidative stress, or gramicidin D, a toxin that selectively permeabilizes cell membranes, prior to infection. These regimens stimulated gene expression from IE-deficient HSV-1 mutants in a promoter sequence-independent manner and also overcame the replication defect of ICP0-null mutants. Reactivation of gene expression from quiescent HSV-1 genomes and the resumption of virus replication were observed following addition of arsenite or gramicidin D to cultures. Both agents induced reorganization of nuclear domain 10 structures, the sites of quiescent genomes, but appeared to do so through different mechanisms. The results demonstrate that the physiological state of the cell is important in determining the outcome of infection with IE-deficient HSV-1 and show novel methods for reactivating quiescent HSV-1 in fibroblasts with a high efficiency.

Genital herpes has played a more important role than any other sexually transmitted infection in driving HIV prevalence in Africa

Background

Extensive evidence from observational studies suggests a role for genital herpes in the HIV epidemic. A number of herpes vaccines are under development and several trials of the efficacy of HSV-2 treatment with acyclovir in reducing HIV acquisition, transmission, and disease progression have just reported their results or will report their results in the next year. The potential impact of these interventions requires a quantitative assessment of the magnitude of the synergy between HIV and HSV-2 at the population level.

Methods and Findings

A deterministic compartmental model of HIV and HSV-2 dynamics and interactions was constructed. The nature of the epidemiologic synergy was explored qualitatively and quantitatively and compared to other sexually transmitted infections (STIs). The results suggest a more substantial role for HSV-2 in fueling HIV spread in sub-Saharan Africa than other STIs. We estimate that in settings of high HSV-2 prevalence, such as Kisumu, Kenya, more than a quarter of incident HIV infections may have been attributed directly to HSV-2. HSV-2 has also contributed considerably to the onward transmission of HIV by increasing the pool of HIV positive persons in the population and may explain one-third of the differential HIV prevalence among the cities of the Four City study. Conversely, we estimate that HIV had only a small net impact on HSV-2 prevalence.

Conclusions

HSV-2 role as a biological cofactor in HIV acquisition and transmission may have contributed substantially to HIV particularly by facilitating HIV spread among the low-risk population with stable long-term sexual partnerships. This finding suggests that prevention of HSV-2 infection through a prophylactic vaccine may be an effective intervention both in nascent epidemics with high HIV incidence in the high risk groups, and in established epidemics where a large portion of HIV transmission occurs in stable partnerships.

Prevalent herpes simplex virus type 2 infection is associated with altered vaginal flora and an increased susceptibility to multiple sexually transmitted infections

BACKGROUND

Prevalent herpes simplex virus type 2 (HSV-2) infection increases human immunodeficiency virus acquisition. We hypothesized that HSV-2 infection might also predispose individuals to acquire other common sexually transmitted infections (STIs).

METHODS

We studied the association between prevalent HSV-2 infection and STI incidence in a prospective, randomized trial of periodic STI therapy among Kenyan female sex workers. Participants were screened monthly for infection with Neisseria gonorrhoeae and Chlamydia trachomatis, and at least every 6 months for bacterial vaginosis (BV) and infection with Treponema pallidum, Trichomonas vaginalis, and/or HSV-2.

RESULTS

Increased prevalence of HSV-2 infection and increased prevalence of BV were each associated with the other; the direction of causality could not be determined. After stratifying for sexual risk-taking, BV status, and antibiotic use, prevalent HSV-2 infection remained associated with an increased incidence of infection with N. gonorrhoeae (incidence rate ratio [IRR], 4.3 [95% confidence interval {CI}, 1.5-12.2]), T. vaginalis (IRR, 2.3 [95% CI, 1.3-4.2]), and syphilis (IRR, 4.7 [95% CI, 1.1-19.9]). BV was associated with increased rates of infection with C. trachomatis (IRR, 2.1 [95% CI, 1.1-3.8]) and T. vaginalis (IRR, 8.0 [95% CI, 3.2-19.8]). CONCLUSION; Increased prevalences of HSV-2 infection and BV were associated with each other and also associated with enhanced susceptibility to an overlapping spectrum of other STIs. Demonstration of causality will require clinical trials that suppress HSV-2 infection, BV, or both.

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.

The genital tract immune milieu: an important determinant of HIV susceptibility and secondary transmission

HIV is generally sexually acquired across the genital or rectal mucosa after exposure to the genital secretions of an HIV-infected partner. Most exposures to HIV do not result in infection, likely due to protection afforded by an intact mucosal epithelium, as well as by innate and adaptive mucosal immune factors present in the genital tract. Another important mucosal determinant of transmission may be the number and activation status of potential HIV target cells, including CCR5/CD4+ T cells and DC-SIGN+ dendritic cells. The simultaneous presence of other genital infections, including classical sexually transmitted infections (STIs), can enhance HIV susceptibility either by breaching the epithelial barrier, recruiting HIV target cells to the genital tract, or by generating a pro-inflammatory local immune milieu. In HIV-infected individuals, genital co-infections increase HIV levels in the genital secretions, thereby increasing secondary sexual transmission. Co-infections that act as important HIV cofactors include human cytomegalovirus (CMV), Herpes simplex virus type 2 (HSV2), Neisseria gonorrhoeae and many others. Strategies focused on genital co-infections, such as vaccines, microbicides and suppressive therapy, are feasible in the short term and have the potential to curb the pandemic.

Reduction of HIV-1 RNA levels with therapy to suppress herpes simplex virus

BACKGROUND

Epidemiologic data suggest that infection with herpes simplex virus type 2 (HSV-2) is associated with increased genital shedding of human immunodeficiency virus type 1 (HIV-1) RNA and HIV-1 transmissibility.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of HSV suppressive therapy with valacyclovir (at a dose of 500 mg twice daily) in Burkina Faso among women who were seropositive for HIV-1 and HSV-2; all were ineligible for highly active antiretroviral therapy. The patients were followed for 24 weeks (12 weeks before and 12 weeks after randomization). Regression models were used to assess the effect of valacyclovir on the presence and quantity of genital and plasma HIV-1 RNA and genital HSV-2 DNA during treatment, adjusting for baseline values, and to evaluate the effect over time.

RESULTS

A total of 140 women were randomly assigned to treatment groups; 136 were included in the analyses. At enrollment, the median CD4 cell count was 446 cells per cubic millimeter, and the mean plasma viral load was 4.44 log10 copies per milliliter. With the use of summary-measures analysis, valacyclovir therapy was found to be associated with a significant decrease in the frequency of genital HIV-1 RNA (odds ratio, 0.41; 95% confidence interval [CI], 0.21 to 0.80) and in the mean quantity of the virus (log(10) copies per milliliter, -0.29; 95% CI, -0.44 to -0.15). However, there was no significant decrease in detection of HIV (risk ratio, 0.93; 95% CI, 0.81 to 1.07). HSV suppressive therapy also reduced the mean plasma HIV-1 RNA level by 0.53 log(10) copy per milliliter (95% CI, -0.72 to -0.35). Repeated-measures analysis showed that these effects became significantly stronger during the 3 months of follow-up.

CONCLUSIONS

HSV suppressive therapy significantly reduces genital and plasma HIV-1 RNA levels in dually infected women. This finding may have important implications for HIV control. (ClinicalTrials.gov number, NCT00158509 [ClinicalTrials.gov].).

HSV-2- and HIV-1- permissive cell lines co-infected by HSV-2 and HIV-1 co-replicate HSV-2 and HIV-1 without production of HSV-2/HIV-1 pseudotype particles

Background

Herpes simplex virus type 2 (HSV-2) is a major cofactor of human immunodeficiency virus type 1 (HIV-1) sexual acquisition and transmission. In the present study, we investigated whether HIV-1 and HSV-2 may interact at the cellular level by forming HIV-1 hybrid virions pseudotyped with HSV-2 envelope glycoproteins, as was previously reported for HSV type 1.

Methods

We evaluated in vitro the production of HSV-2/HIV-1 pseudotypes in mononuclear CEM cells and epithelial HT29 and P4P cells. We analyzed the incorporation into the HIV-1 membrane of HSV-2 gB and gD, two major HSV-2 glycoproteins required for HSV-2 fusion with the cell membrane, in co-infected cells and in HIV-1-infected P4P cells transfected by plasmids coding for gB or gD.

Results

We show that HSV-2 and HIV-1 co-replicated in dually infected cells, and gB and gD were co-localized with gp160. However, HIV-1 particles, produced in HIV-1-infected cells expressing gB or gD after transfection or HSV-2 superinfection, did not incorporate either gB or gD in the viral membrane, and did not have the capacity to infect cells normally non-permissive for HIV-1, such as epithelial cells.

Conclusion

Our results do not support the hypothesis of HSV-2/HIV-1 pseudotype formation and involvement in the synergistic genital interactions between HIV-1 and HSV-2.

Impact of suppressive herpes therapy on genital HIV-1 RNA among women taking antiretroviral therapy: a randomized controlled trial

OBJECTIVE

To demonstrate a causal relationship between herpes simplex virus 2 (HSV-2) and increased genital HIV-1-RNA shedding in women on HAART.

DESIGN

A randomized, double-blind, placebo-controlled trial of herpes-suppressive therapy (valacyclovir 500 mg twice a day) in HIV-1/HSV-2-infected women taking HAART in Burkina Faso.

METHODS

Participants were followed for a total of 12 biweekly visits before and after randomization. The presence and frequency of genital and plasma HIV-1 RNA, and of genital HSV-2 were assessed using summary measures, adjusting for baseline values. Random effect linear regression models were used to assess the impact of treatment on genital and plasma viral loads among visits with detectable virus.

RESULTS

Sixty women were enrolled into the trial. Their median CD4 lymphocyte count was 228 cells/mul, and 83% had undetectable plasma HIV-1 RNA at baseline. Valacyclovir reduced the proportion of visits with detectable genital HSV-2 DNA [odds ratio (OR) 0.37, 95% confidence interval (CI) 0.13, 1.05], but had no significant impact on the frequency (OR 0.90, 95% CI 0.31, 2.62) or quantity (reduction of 0.33 log copies/ml, 95% CI -0.81, 0.16) of genital HIV-1 RNA. However, according to pre-defined secondary analyses restricted to women who shed HIV-1 at least once in the baseline phase, valacyclovir reduced both the proportion of visits with detectable HIV-1 shedding (OR 0.27, 95% CI 0.07, 0.99) and the quantity of genital HIV-1 RNA during these visits (-0.71 log10 copies/ml, 95% CI -1.27, -0.14).

CONCLUSION

HSV-2 facilitates residual genital HIV-1 replication among dually infected women taking HAART despite HIV-1 suppression at the systemic level.

Cellular stress rather than stage of the cell cycle enhances the replication and plating efficiencies of herpes simplex virus type 1 ICP0- viruses

This lab reported previously that the plating efficiency of a herpes simplex virus type 1 ICP0-null mutant was enhanced upon release from an isoleucine block which synchronizes cells to G1 phase (W. Cai and P. A. Schaffer, J. Virol. 65:4078-4090, 1991). Peak plating efficiency occurred as cells cycled out of G1 and into S phase, suggesting that the enhanced plating efficiency was due to cellular activities present in late G1/early S phase. We have found, however, that the enhanced plating efficiency did not occur when cells were synchronized by alternative methods. We now report that the plating efficiency of ICP0- viruses is not enhanced at a particular stage of the cell cycle but rather is enhanced by specific cellular stresses. Both the plating and replication efficiencies of ICP0- viruses were enhanced as much as 25-fold to levels similar to that of wild-type virus when monolayers were heat shocked prior to infection. In addition to heat shock, UV-C irradiation but not cold shock of monolayers prior to infection resulted in enhanced plating efficiency. We further report that the effect of cellular stress is transient and that cell density rather than age of the monolayers is the primary determinant of ICP0- virus plating efficiency. As both cell stress and ICP0 are required for efficient reactivation from latency, the identification of cellular activities that complement ICP0- viruses may lead to the identification of cellular activities that are important for reactivation from neuronal latency.

Phosphorylation site mutations affect herpes simplex virus type 1 ICP0 function

The herpes simplex virus type 1 (HSV-1) immediate-early (IE) regulatory protein infected-cell protein 0 (ICP0) is a strong and global transactivator of both viral and cellular genes. In a previous study, we reported that ICP0 is highly phosphorylated and contains at least seven distinct phosphorylation signals as determined by phosphotryptic peptide mapping (D. J. Davido et al., J. Virol. 76:1077-1088, 2002). Since phosphorylation affects the activities of many viral regulatory proteins, we sought to determine whether the phosphorylation of ICP0 affects its functions. To address this question, it was first necessary to identify the regions of ICP0 that are phosphorylated. For this purpose, ICP0 was partially purified, and phosphorylation sites were mapped by microcapillary high-pressure liquid chromatography tandem mass spectrometry. Three phosphorylated regions containing 11 putative phosphorylation sites, all within or adjacent to domains important for the transactivating activity of ICP0, were identified. The 11 sites were mutated to alanine as clusters in each of the three regions by site-directed mutagenesis, generating plasmids expressing mutant forms of ICP0: Phos 1 (four mutated sites), Phos 2 (three mutated sites), and Phos 3 (four mutated sites). One-dimensional phosphotryptic peptide analysis confirmed that the phosphorylation state of each Phos mutant form of ICP0 is altered relative to that of wild-type ICP0. In functional assays, the ICP0 phosphorylation site mutations affected the subcellular and subnuclear localization of ICP0, its ability to alter the staining pattern of the nuclear domain 10 (ND10)-associated protein PML, and/or its transactivating activity in Vero cells. Only mutations in Phos 1, however, impaired the ability of ICP0 to complement the replication of an ICP0 null mutant in Vero cells. This study thus suggests that phosphorylation is an important regulator of ICP0 function.

Cutaneous markers of HIV infection

Despite the development of laboratory methods, dermatological symptoms are a basic index of the presence and physical course of HIV infection. HIV infection usually undergoes a long latent period, proceeds to a period of immunodeficiency-related symptoms, and ends in an advanced immunodeficiency state characterized by opportunistic infections and neoplasms. Occasionally, dermatological manifestations can be the first signs of asymptomatic disease, indices of advanced immunodeficiency, or symptoms of opportunistic infections or neoplasms. The variety of symptoms and signs for the skin during the course of HIV infection is a consequence of the progressing immunodeficiency and therefore indicates the underlying disorder. The use of these manifestations is a challenge for clinical praxis.

The differential requirement for cyclin-dependent kinase activities distinguishes two functions of herpes simplex virus type 1 ICP0

Herpes simplex virus type 1 (HSV-1) ICP0 directs the degradation of cellular proteins associated with nuclear structures called ND10, a function thought to be closely associated with its broad transactivating activity. Roscovitine (Rosco), an inhibitor of cyclin-dependent kinases (cdks), inhibits the replication of HSV-1, HSV-2, human cytomegalovirus, varicella-zoster virus, and human immunodeficiency virus type 1 by inhibiting specific steps or activities of viral regulatory proteins, indicating the broad and pleiotropic effects that cdks have on the replication of these viruses. We previously demonstrated that Rosco inhibits the transactivating activity of ICP0. In the present study, we asked whether Rosco also affects the ability of ICP0 to direct the degradation of ND10-associated proteins. For this purpose, WI-38 cells treated with cycloheximide (CHX) were mock infected or infected with wild-type HSV-1 or an ICP0(-) mutant (7134). After release from the CHX block, the infections were allowed to proceed for 2 h in the presence or absence of Rosco at a concentration known to inhibit ICP0's transactivating activity. The cells were then examined for the presence of ICP0 and selected ND10-associated antigens (promyelocytic leukemia antigen [PML], sp100, hDaxx, and NDP55) by immunofluorescence. Staining for the ND10-associated antigens was detected in </=20% of KOS-infected cells in the presence or absence of Rosco, demonstrating that Rosco-sensitive kinases are not required for ICP0's ability to direct the dispersal or degradation of these antigens. In contrast, >90% of 7134- and mock-infected cells stained positive for all ND10-associated antigens in the presence or absence of Rosco. Similar results were obtained with a non-ND10-associated antigen, DNA-PK(cs), a known target of ICP0-directed degradation. The results of the PML and DNA-PK(cs) immunofluorescence studies correlated with a decrease in the levels of these proteins as determined by Western blotting. Thus, the differential requirement for Rosco-sensitive cdk activities distinguishes ICP0's ability to direct the dispersal or degradation of cellular proteins from its transactivating activity.

Herpesvirus quiescence in neuronal cells. V: forskolin-responsiveness of the herpes simplex virus type 1 alpha0 promoter and contribution of the putative cAMP response element

The herpes simplex virus (HSV)-1 alpha0 promoter contains a putative cAMP response element (CRE) located at positions -68 to -60 with respect to the initiation of transcription. In this report, the authors examined the functionality of this element using (1) luciferase reporter gene assays in nerve growth factor-differentiated (ND)-PC12 cells and (2) virus-induced activation from quiescently infected (QIF)-PC12 cells. The putative alpha0 CRE was completely eliminated by digestion with the restriction enzyme Tsp45I followed by mung bean nuclease treatment. The mutated region was verified by DNA sequencing and was inserted into the alpha0-luciferase reporter plasmid (pRDalpha0-LUC) creating (pRDalpha0deltaCRE-LUC), and into the HSV-1 genome of strain 17(+)(alpha0deltaCRE). Insertion into both copies of the alpha0 promoter was verified by Southern blot analysis. ND-PC12 cells transfected with pRDalpha0-LUC and pRDalpha0deltaCRE-LUC plasmids responded similarly to forskolin (50 microM), with approximately 250% increases in luciferase activity compared to mock-treated cultures as measured 3 days following treatment. When QIF-PC12 cultures established with HSV-1 strain 17(+) and alpha0deltaCRE were treated with forskolin (50 microM) 17 days post infection, virus was detected in 9/24 (37.5%) and 13/24 (54.2%) of induced cultures by day 8 post treatment, respectively. In contrast, virus was detected in 0/23 and 1/24 (4.2%) of mock-treated cultures by day 8 post treatment for wild-type and mutant viruses, respectively. These findings indicate that the alpha0 promoter is forskolin responsive, the purported CRE of the alpha0 promoter does not confer forskolin responsiveness in ND-PC12 cells, and this element is not required for reactivation of HSV-1 from QIF-PC12 cells.

Herpes simplex virus type 1 can either suppress or enhance human immunodeficiency virus type 1 replication in CD4-positive T lymphocytes

It was proposed recently that CEM CD4-positive T cells infected chronically by herpes simplex virus type 1 (HSV-1) and human immunodeficiency virus type 1 (HIV-1) (CEM(HSV/HIV)) may be used as a model for studying HIV/HSV interactions. To ascertain whether HSV-HIV coinfection of T lymphocytes has a role in promoting progression of lentiviral infection, T cells infected chronically by either HSV-1 (CEM(HSV)) or HIV-1 (CEM(HIV)) were challenged with a superinfecting dose of HIV-1 or HSV-1. The results show a positive influence on HIV growth when CEM(HIV) cells were superinfected with HSV-1 to an extent that was dependent on the multiplicity of superinfection used. In contrast, HIV superinfection of CEM(HSV) cells resulted in a delay of HIV-1 production and in a lack of HSV-mediated LTR transactivation. These effects were due to cell growth inhibition and apoptosis, resulting from persistent HSV-1 infection. Treatment of CEM(HSV) with acyclovir inhibited completely the HSV-1 cytopathic effects and allowed efficient HIV-1 replication. These data may be relevant in clarifying the role of HIV/HSV interaction in the pathogenesis of AIDS.

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.

Absence of IE1 p72 protein function during low-multiplicity infection by human cytomegalovirus results in a broad block to viral delayed-early gene expression

Human cytomegalovirus (HCMV) ie1 deletion mutant CR208 is profoundly growth deficient after low-multiplicity infection of primary fibroblasts. Previously, we showed that many fewer cells infected with CR208 at low multiplicity accumulated the delayed-early (DE) protein ppUL44 than accumulated the immediate-early 2 (IE2) p86 protein, indicating a high frequency of abortive infections. We now demonstrate that accumulation of all DE proteins tested was defective after low-multiplicity infection in the absence of IE1 p72. Accumulation of the DE proteins pUL57, pUL98, and pUL69 followed a pattern very similar to that of ppUL44 during low-multiplicity CR208 infection. Accumulation of the ppUL112-113 proteins occurred in a greater proportion of cells than other DE proteins during low-multiplicity CR208 infection, but was still deficient relative to wild-type virus. We also show for the first time that steady-state levels of many DE RNAs were reduced during low-multiplicity CR208 infection and that by in situ hybridization of the abundant cytoplasmic 2.7-kb TRL4 DE (beta2.7) RNA, a viral DE RNA followed a defective pattern of accumulation similar to that of ppUL44. Furthermore, transfected DE promoter-reporter constructs were found in transient assays to be considerably less responsive to CR208 infection than to infection by wild-type Towne virus. Our results indicate a general defect in DE gene expression following low-multiplicity HCMV infection in the absence of functional IE1 p72, most probably mediated by reduced transcription of DE genes and by the reduced accumulation of DE RNAs.

The cyclin-dependent kinase inhibitor roscovitine inhibits the transactivating activity and alters the posttranslational modification of herpes simplex virus type 1 ICP0

The cyclin-dependent kinase (cdk) inhibitor Roscovitine (Rosco) reduces transcription of herpes simplex virus early genes significantly, even in the presence of wild-type levels of immediate-early (IE) viral proteins, suggesting that the transactivating functions of IE proteins may require the activities of one or more Rosco-sensitive cdk (L. M. Schang, A. Rosenberg, and P. A. Schaffer, J. Virol. 73:2161-2172, 1999). Based on this observation, we sought to determine whether Rosco alters the transactivating activity and posttranslational modification state of the IE protein, infected cell protein 0 (ICP0), in KOS6beta-infected Vero cells. KOS6beta is a KOS-derived recombinant virus containing an ICP0-inducible ICP6 promoter::lacZ cassette. To monitor ICP0's transactivating activity, KOS6beta-infected cells were released from a cycloheximide (CHX)-mediated protein synthesis block into medium with or without Rosco, and beta-galactosidase activity was measured. Rosco inhibited the ability of ICP0 to transactivate the ICP6 promoter by 50-fold. This inhibition was shown not to be a consequence of inhibition of ICP6 basal promoter activity or aberrant nuclear localization of ICP0. Rosco also altered the electrophoretic mobility of a portion of ICP0 molecules derived from KOS-infected cells following reversal of a CHX block. Notably, however, Rosco had only a minimal effect on the phosphorylation state of ICP0. We conclude that ICP0's transactivating activity requires Rosco-sensitive cdks and hypothesize that these cdks regulate the functions of cellular enzymes which modify ICP0, and are, consequently, required for its transactivating activity. Thus, we propose that Rosco regulates ICP0's posttranslational state by mechanisms other than, or in addition to, phosphorylation.

Contribution of immune activation to the pathogenesis and transmission of human immunodeficiency virus type 1 infection

The life cycle of human immunodeficiency virus type 1 (HIV-1) is intricately related to the activation state of the host cells supporting viral replication. Although cellular activation is essential to mount an effective host immune response to invading pathogens, paradoxically the marked systemic immune activation that accompanies HIV-1 infection in vivo may play an important role in sustaining phenomenal rates of HIV-1 replication in infected persons. Moreover, by inducing CD4+ cell loss by apoptosis, immune activation may further be central to the increased rate of CD4+ cell turnover and eventual development of CD4+ lymphocytopenia. In addition to HIV-1-induced immune activation, exogenous immune stimuli such as opportunistic infections may further impact the rate of HIV-1 replication systemically or at localized anatomical sites. Such stimuli may also lead to genotypic and phenotypic changes in the virus pool. Together, these various immunological effects on the biology of HIV-1 may potentially enhance disease progression in HIV-infected persons and may ultimately outweigh the beneficial aspects of antiviral immune responses. This may be particularly important for those living in developing countries, where there is little or no access to antiretroviral drugs and where frequent exposure to pathogenic organisms sustains a chronically heightened state of immune activation. Moreover, immune activation associated with sexually transmitted diseases, chorioamnionitis, and mastitis may have important local effects on HIV-1 replication that may increase the risk of sexual or mother-to-child transmission of HIV-1. The aim of this paper is to provide a broad review of the interrelationship between immune activation and the immunopathogenesis, transmission, progression, and treatment of HIV-1 infection in vivo.

Induction of Human Immunodeficiency Virus 1 Replication by Human Herpesvirus 8

Background.—Human immunodeficiency virus 1 (HIV-1)–infected individuals are commonly infected with herpesviruses, including cytomegalovirus, herpes simplex virus, varicella-zoster virus, and human herpesvirus 8 (HHV-8, also known as Kaposi sarcoma–associated herpesvirus [KSHV]). Previous studies have demonstrated that coinfection with herpesviruses can modulate HIV-1 replication. This can occur either through direct interaction between the 2 viruses or through secondary effects resulting from the release of cellular factors in response to infection.

Objective.—To investigate HIV-1 replication in the presence and absence of HHV-8.

Design and Methods.—HIV-1 replication was analyzed following culture of HIV-1–infected CD4+ T cells in the presence of HHV-8 infected B-cell lines or control, uninfected B-cell lines. To confirm and extend the results of these in vitro studies, HIV-1–infected T cells were injected into human skin transplanted onto severe combined immunodeficient mice. The human skin was also injected with purified HHV-8 or phosphate-buffered saline as a control and HIV replication measured in biopsy specimens taken 5 to 8 days later.

Results and Conclusions.—The results demonstrated a significant increase in HIV-1 replication in the presence of HHV-8 in both the in vitro and in vivo model systems. Although the mechanism responsible for HHV-8 induction of HIV-1 replication remains to be identified, the results indicate that these 2 viruses may interact at the molecular level in coinfected patients, resulting in increased HIV-1 viral load.

Analysis of fumonisin B1-induced apoptosis

Fumonisins are mycotoxins produced by Fusarium moniliforme, a prevalent fungus that infects corn and other cereal grains. Fumonisin B1(FB1 is the most common mycotoxin produced by F. moniliforme, suggesting it has toxicologic significance. The structure of FB1 resembles sphingoid bases, and it inhibits ceramide synthase. Because sphingoid bases regulate cell growth, differentiation, transformation, and apoptosis, it is not surprising to find that FB1 can alter growth of certain mammalian cells. Previous studies concluded FB1-induced apoptosis, or cell cycle arrest, in African green monkey kidney fibroblasts (CV-1). In this study we have identified genes that inhibit FB1 induced apoptosis in CV-1 cells and two mouse embryo fibroblasts (MEF). A baculovirus gene, inhibitor of apoptosis (CpIAP), protected these cells from apoptosis. CpIAP blocks apoptosis induced by the tumor necrosis factor (TNF) pathway as well as other mechanisms. Further support for the involvement of the TNF signal transduction pathway in FB1 induced apoptosis was the cleavage of caspase 8. Inhibition of caspases by the baculovirus gene (italic)p35 also inhibited FB1-induced apoptosis. The tumor suppressor gene p53 was not required for FB1 induced apoptosis because p53-/- MEF undergo apoptosis following FB1 treatment. Furthermore, Bcl-2 was not an effective inhibitor of FB1-induced apoptosis in CV-1 cells or p53+/+ MEF. In summary, these results provide new information to help understand the mechanism by which FB1 induces apoptosis.

Perturbation of cell cycle progression and cellular gene expression as a function of herpes simplex virus ICP0

Herpes simplex virus type 1 is capable of inhibiting host cell DNA synthesis following lytic infection. However, the mechanism and nature of potential effects on cell cycle progression have not been described. In this report, we characterize the dysregulation of the cell cycle following infection with the replication-incompetent virus d106, where immediate-early gene expression is restricted to infected-cell polypeptide 0 (ICP0) and the expression of all other viral genes is dramatically reduced or is not observed. Infection with d106 resulted in the accumulation of cells in both the G(1)/S and G(2)/M compartments, consistent with cell cycle arrest at both checkpoints. The isogenic variant d109, which does not express any viral proteins, failed to induce this phenotype, suggesting that the expression of ICP0 is crucial for cell cycle arrest. Analysis of global cellular gene expression patterns following infection with d106 and d109 revealed that a relatively small subset of cellular genes were induced as a consequence of ICP0 expression. A number of these genes induced in the presence of ICP0 are classically considered p53-responsive genes, including p21, gadd45, and mdm-2. However, infection with d106 of cells with both alleles of p53 deleted resulted in the same cell cycle arrest phenotype and similar cellular gene expression patterns, suggesting that the expression of ICP0 results in cell cycle arrest potentially via p53-dependent and p53-independent mechanisms. In addition, it was found that the effects of infection with d106 on viral and cellular gene expression were similar to the effects observed following treatment of cells with the histone deacetylase inhibitor trichostatin A.