Transmission of human herpesvirus 8: an update

The literature discusses oral manifestations caused by sexually transmitted viruses: a narrative review

This review provides practical recommendations for dental practitioners in dealing with oral lesions associated with sexually transmitted diseases (STDs), offering clinically relevant insights to increase the awareness of these diseases in the mainstream of everyday practice. STDs are acquired through unprotected vaginal, anal or oral sex and are caused by more than 30 different types of bacteria, viruses and protozoa. Saliva, precum, semen, vaginal secretions and menstrual blood could be likely vehicles of infections and defensive barriers to infection by pathogenic microbes could be represented via intact mucosal membrane, the diluent function of saliva, and the antimicrobial action of salivary enzymes that collectively contribute to oral health and protection. STD, can directly and indirectly affect mucous membranes, manifesting with characteristic diagnostic signs and lesions. Given their potential oral manifestations, dental professionals need a comprehensive understanding of STD. The findings of this review lay a foundation for comprehending several STDs, emphasizing the importance of physicians as well dental practitioners being open to discussing sexuality issues with patients and providing appropriate therapeutic interventions.

Molecular detection and genotyping of human herpes virus 8 in blood donors in Congo

OBJECTIVES

Human herpesvirus 8 (HHV8) is rarely studied in Congo, despite its prevalence in Africa. Among healthy individuals, HHV-8 does not always lead to a life-threatening infection; however, in immunocompromised individuals, it could lead to more severe disease. The distribution of HHV-8 genotypes varies depending on ethnicity and geographic region.

METHOD

A prospective cross-sectional study included 265 samples from healthy blood donors from the National Blood Transfusion Center in Brazzaville, with an average age of 35 years, with extremes ranging from 18 to 60 years. After DNA extraction, a nested PCR was carried out for molecular detection, followed by genotyping by amplification of specific primers.

RESULT

In this study, 4.9% were positive for molecular detection of HHV-8 DNA. All HHV-8 positive DNA samples that were subjected to genotyping by amplification with specific primers allowing discrimination of two major genotypes (A and B). Genotype A was identified in 5 (1.9%) samples and genotype B in 2 (0.7%) samples, indicating that both genotypes were predominant. The remaining viral DNA samples not identified as the major genotypes were classified as «indeterminate» and consisted of 6 (2.3%) samples.

CONCLUSION

The results of the study suggest that Congo is an area where HHV-8 infection is endemic.

Evaluation of two commercial diagnostic methods for HHV-8 viral load assessment

Objectives

Human herpesvirus-8 (HHV-8) can cause Kaposi's sarcoma or B lymphoproliferative disorders such as multicentric Castleman disease. Patient follow-up is based on assessing the HHV-8 viral load, which is usually achieved using real-time polymerase chain reaction (PCR). The HHV-8 Premix r-gene kit (BioMérieux) was used by some laboratories in the past, but BioMérieux ceased the production and distribution of this kit in 2021-2022. Other kits need to be tested so that they can be used for diagnostic purposes. Here we evaluated two commercial kits: HHV8 ELITe MGB Kit (ELITech) and Quanty HHV-8 (Clonit) and compared them with the HHV-8 Premix r-gene kit.

Methods

We used whole blood samples that had previously been tested with the HHV-8 Premix r-gene kit for diagnostic purposes. Overall, 46 samples (37 HHV-8-positive and 9 HHV-8-negative) were tested with the ELITe MGB Kit and 37 (29 HHV-8-positive and 8 HHV-8-negative) with the Quanty HHV-8 kit. The different methods were compared using Bland-Altman and Passing-Bablok tests with Analyse-it software.

Results

Qualitative results were concordant except for one HHV-8 low-positive sample that was found to be negative by the ELITe MGB Kit. The quantitative results were also concordant; both kits showed mean differences of 0.58 log10 copies/ml and 0.73 log10 copies/ml, respectively, compared to the Premix r-gene kit.

Conclusions

Both the methods tested produced acceptable results and could be used for diagnostic purposes. It should be remembered that there is no international standard for HHV-8 quantification and that patients should always be followed using the same method.

Hijacking of nucleotide biosynthesis and deamidation-mediated glycolysis by an oncogenic herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and multiple types of B cell malignancies. Emerging evidence demonstrates that KSHV reprograms host-cell central carbon metabolic pathways, which contributes to viral persistence and tumorigenesis. However, the mechanisms underlying KSHV-mediated metabolic reprogramming remain poorly understood. Carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase (CAD) is a key enzyme of the de novo pyrimidine synthesis, and was recently identified to deamidate the NF-κB subunit RelA to promote aerobic glycolysis and cell proliferation. Here we report that KSHV infection exploits CAD for nucleotide synthesis and glycolysis. Mechanistically, KSHV vCyclin binds to and hijacks cyclin-dependent kinase CDK6 to phosphorylate Ser-1900 on CAD, thereby activating CAD-mediated pyrimidine synthesis and RelA-deamidation-mediated glycolytic reprogramming. Correspondingly, genetic depletion or pharmacological inhibition of CDK6 and CAD potently impeded KSHV lytic replication and thwarted tumorigenesis of primary effusion lymphoma (PEL) cells in vitro and in vivo. Altogether, our work defines a viral metabolic reprogramming mechanism underpinning KSHV oncogenesis, which may spur the development of new strategies to treat KSHV-associated malignancies and other diseases.

Human Herpesvirus 8 in Australia: DNAemia and Cumulative Exposure in Blood Donors

Human herpesvirus 8 (HHV-8), the causative agent of Kaposi’s sarcoma, multicentric Castleman’s disease and primary effusion lymphoma, predominantly manifests in immunocompromised individuals. However, infection in immunocompetent individuals does occur. The prevalence of HHV-8 exposure in blood donors from non-endemic countries ranges between 1.2% and 7.3%. Nothing was known about the prevalence in Australian blood donors. Therefore, this study investigated the active and cumulative exposure of HHV-8 in this cohort. Plasma samples (n = 480) were collected from eastern Australian blood donors and were tested for HHV-8 DNA by qPCR, and for HHV-8 antibodies by two different ELISAs. Samples initially positive on either ELISA were retested in duplicate on both, and on a mock-coated ELISA. Any samples positive two or three out of the three times tested on at least one ELISA, and repeat negative on the mock-coated ELISA, were assigned as repeat positive. None of the 480 samples tested contained HHV-8 DNA. Serological testing revealed 28 samples (5.83%; 95% CI: 3.74−7.93%) had antibodies to HHV-8. There was no difference (p > 0.05) in seropositivity between sex or with increasing age. This is the first study to show serological evidence of cumulative HHV-8 exposure and no HHV-8 DNAemia within a select blood donor population in Australia. Our molecular and serological data is consistent with published results for blood donors residing in HHV-8 non-endemic countries, which shows the prevalence to be very low.

Single-cell analysis of Kaposi's sarcoma-associated herpesvirus infection in three-dimensional air-liquid interface culture model

The oral cavity is the major site for transmission of Kaposi's sarcoma-associated herpesvirus (KSHV), but how KSHV establishes infection and replication in the oral epithelia remains unclear. Here, we report a KSHV spontaneous lytic replication model using fully differentiated, three-dimensional (3D) oral epithelial organoids at an air-liquid interface (ALI). This model revealed that KSHV infected the oral epithelia when the basal epithelial cells were exposed by damage. Unlike two-dimensional (2D) cell culture, 3D oral epithelial organoid ALI culture allowed high levels of spontaneous KSHV lytic replication, where lytically replicating cells were enriched at the superficial layer of epithelial organoid. Single cell RNA sequencing (scRNAseq) showed that KSHV infection induced drastic changes of host gene expression in infected as well as uninfected cells at the different epithelial layers, resulting in altered keratinocyte differentiation and cell death. Moreover, we identified a unique population of infected cells containing lytic gene expression at the KSHV K2-K5 gene locus and distinct host gene expression compared to latent or lytic infected cells. This study demonstrates an in vitro 3D epithelial organoid ALI culture model that recapitulates KSHV infection in the oral cavity, where KSHV undergoes the epithelial differentiation-dependent spontaneous lytic replication with a unique cell population carrying distinct viral gene expression.

Kaposi's Sarcoma Management from a Plastic Surgery Perspective

Kaposi's Sarcoma (KS) is a low-grade angioproliferative tumor arising from endothelial cells and associated with Human Herpes Virus 8 infection. Although KS cases are not rare and there are considerable number of patients referred for surgical excision, the plastic surgery literature on KS is exceptionally scarce. Thirty patients who were operated with the diagnosis of KS between March 2015 and January 2020 were included. Preoperative HIV tests and detailed whole-body examinations of the patients were performed. As a surgical method, for lesions with sizes ranging from 0.5 * 1 cm to 2 * 3 cm, excisions were made over the deep skin fascia by placing a margin between 0.5-1 cm, considering the anatomical location and elasticity of the skin. Primary repair was performed in 40 lesions and 12 lesions of 8 patients were repaired with a skin graft. In four patients the repair was performed with local skin flaps. Higher upper extremity involvement, less systemic involvement and less pronounced male predominance have been important results in our study that we have found different from the literature data. Compared to the therapies such as radiotherapy, laser, or chemotherapy which require several administrations; one-stage surgical excision of the lesions provides remarkable advantages.

The prevalence of human herpesvirus 8 in normal, premalignant, and malignant cervical samples of Iranian women

BACKGROUND

Regard to this fact that the main transmission route of HPV and HHV-8 is via sexual activity, it is reasonable to speculate that coinfection of HPV and HHV-8 may have been played an important role in the development of cervical cancer. The aim of this study was to estimate the prevalence of HHV-8 and the frequency of HPV and HHV-8 coinfection in cervical samples of patients with cervical cancer and healthy individuals.

METHODS

In total, 364 samples from 61 patients with cervical cancer, 124 women with premalignant lesions, and 179 healthy individuals were investigated by nested-PCR.

RESULTS

The frequency of HHV-8 was found to be 22.9%, 17.7%, and 14.5% in cervical cancer, premalignant lesions, and normal specimens, respectively (P = 0.308). The overall prevalence of coinfection between HHV-8 and HPV was shown to be 16.2%. The HPV prevalence was higher in HHV-8 positive samples than HHV-8 negative specimens in all three studied groups and this difference was reached a statistically significant level (P = 0.002). However, no significant differences were found between HHV-8 positivity and HPV genotypes (P = 0.08).

CONCLUSIONS

Our results showed the higher rate of HHV-8 genome detection in cervical cancer group than control group. However, future studies with larger sample sizes and evaluation of expression of HHV-8 proteins are warranted.

Solitary incidental primary Kaposi's sarcoma of the glans penis in a patient with no risk factors

Kaposi's sarcoma (KS) is an endothelial neoplasm, originally reported by Moritz Kaposi in 1872. It most commonly involves the lower extremities. Its clinical presentation and course can be quite variable. We present a rare case of solitary incidental primary KS of the glans penis in a circumcised, immunocompetent male who is human immunodeficiency virus seronegative. The lesion was discovered incidentally when the otherwise asymptomatic male presented to our outpatient department for an unrelated issue and was given a physical examination. To our knowledge, this is the first incidentally discovered case of primary penile KS.

Towards Understanding KSHV Fusion and Entry

How viruses enter cells is of critical importance to pathogenesis in the host and for treatment strategies. Over the last several years, the herpesvirus field has made numerous and thoroughly fascinating discoveries about the entry of alpha-, beta-, and gamma-herpesviruses, giving rise to knowledge of entry at the amino acid level and the realization that, in some cases, researchers had overlooked whole sets of molecules essential for entry into critical cell types. Herpesviruses come equipped with multiple envelope glycoproteins which have several roles in many aspects of infection. For herpesvirus entry, it is usual that a collective of glycoproteins is involved in attachment to the cell surface, specific interactions then take place between viral glycoproteins and host cell receptors, and then molecular interactions and triggers occur, ultimately leading to viral envelope fusion with the host cell membrane. The fact that there are multiple cell and virus molecules involved with the build-up to fusion enhances the diversity and specificity of target cell types, the cellular entry pathways the virus commandeers, and the final triggers of fusion. This review will examine discoveries relating to how Kaposi's sarcoma-associated herpesvirus (KSHV) encounters and binds to critical cell types, how cells internalize the virus, and how the fusion may occur between the viral membrane and the host cell membrane. Particular focus is given to viral glycoproteins and what is known about their mechanisms of action.

Gammaherpesvirus entry and fusion: A tale how two human pathogenic viruses enter their host cells

The prototypical human γ-herpesviruses Epstein-Barr virus (EBV) and Kaposi Sarcoma-associated herpesvirus (KSHV) are involved in the development of malignancies. Like all herpesviruses, they share the establishment of latency, the typical architecture, and the conserved fusion machinery to initiate infection. The fusion machinery reflects virus-specific adaptations due to the requirements of the respective herpesvirus. For example, EBV evolved a tropism switch involving either the B- or epithelial cell-tropism complexes to activate fusion driven by gB. Most of the EBV entry proteins and their cellular receptors have been crystallized providing molecular details of the initial steps of infection. For KSHV, a variety of entry and binding receptors has also been reported but the mechanism how receptor binding activates gB-driven fusion is not as well understood as that for EBV. However, the downstream signaling pathways that promote the early steps of KSHV entry are well described. This review summarizes the current knowledge of the key players involved in EBV and KSHV entry and the cell-type specific mechanisms that allow infection of a wide variety of cell types.

LL-37 disrupts the Kaposi's sarcoma-associated herpesvirus envelope and inhibits infection in oral epithelial cells

Oral epithelial cells (OECs) represent the first line of defense against viruses that are spread via saliva, including Kaposi's sarcoma-associated herpesvirus (KSHV). Infection of humans by KSHV and viral pathogenesis begins by infecting OECs. One method OECs use to limit viral infections in the oral cavity is the production of antimicrobial peptides (AMPs), or host defense peptides (HDPs). However, no studies have investigated the antiviral activities of any HDP against KSHV. The goal of this study was to determine the antiviral activity of one HDP, LL-37, against KSHV in the context of infecting OECs. Our results show that LL-37 significantly decreased KSHV's ability to infect OECs in both a structure- and dose-dependent manner. However, this activity does not stem from affecting OECs, but instead the virions themselves. We found that LL-37 exerts its antiviral activity against KSHV by disrupting the viral envelope, which can inhibit viral entry into OECs. Our data suggest that LL-37 exhibits a marked antiviral activity against KSHV during infection of oral epithelial cells, which can play an important role in host defense against oral KSHV infection. Thus, we propose that inducing LL-37 expression endogenously in oral epithelial cells, or potentially introducing as a therapy, may help restrict oral KSHV infection and ultimately KSHV-associated diseases.

Eyelid Kaposi Sarcoma in an HIV-negative Patient

Kaposi sarcoma (KS) is a low-grade, multicentric vascular neoplasm. Most commonly, it involves the skin, but it can occur at any site on the body. The cutaneous lesions are often located on the lower legs, genitalia, oral mucosa, and face. KS is categorized in four different types: classic, endemic, epidemic or AIDS associated, and transplantation associated. We report a case of HIV-negative, classic KS located on the eyelid. The eyelid lesion was completely excised, and after a 1-year follow-up, no recurrences were observed. Ocular involvement by KS in a patient who is serologically negative for HIV is extremely rare.

The Role of aDNA in Understanding the Coevolutionary Patterns of Human Sexually Transmitted Infections

Analysis of pathogen genome data sequenced from clinical and historical samples has made it possible to perform phylogenetic analyses of sexually transmitted infections on a global scale, and to estimate the diversity, distribution, and coevolutionary host relationships of these pathogens, providing insights into pathogen emergence and disease prevention. Deep-sequenced pathogen genomes from clinical studies and ancient samples yield estimates of within-host and between-host evolutionary rates and provide data on changes in pathogen genomic stability and evolutionary responses. Here we examine three groups of pathogens transmitted mainly through sexual contact between modern humans to provide insight into ancient human behavior and history with their pathogens. Exploring ancient pathogen genomic divergence and the ancient viral-host parallel evolutionary histories will help us to reconstruct the origin of present-day geographical distribution and diversity of clinical pathogen infections, and will hopefully allow us to foresee possible environmentally induced pathogen evolutionary responses. Lastly, we emphasize that ancient pathogen DNA research should be combined with modern clinical pathogen data, and be equitable and provide advantages for all researchers worldwide, e.g., through shared data.

Decreased levels of the serum inflammatory biomarkers, sGP130, IL-6, sCRP and BAFF, are associated with increased likelihood of AIDS related Kaposi's sarcoma in men who have sex with men

AIDS-related Kaposi’s sarcoma (AIDS-KS) risk remains substantially elevated compared with the general population, even among patients who receive effective combination antiretroviral therapy. This study investigated the role of inflammatory and immune activating biomarkers in AIDS-KS in men who have sex with men in the Multicenter AIDS Cohort study between 1984 and 2010. Concentrations of 24 serum biomarkers; IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p70, sGP130, sIL-2Rα, sIL-6R, eotaxin, MCP-1, MCP4, MIP 1β, TARC, BLC-BCA1, IP-10, GM-CSF, IFN-γ, BAFF, sCD14, CD27, sTNFR-2, sCRP, and TNF-α were tested longitudinally in 1,501 men. The concentrations of each biomarker were compared between AIDS-KS cases and controls at multiple time points, 0–1 years, 1–2 years, 2–3 year, 3–5 years and over 5 years, prior to KS diagnosis or study termination, using univariate non-parametric Kruskal-Wallis tests and logistic regression, adjusted for HBV and HCV co-infection, race/ethnicity, age at last visit, education, smoking and CD4+ cell count. In univariate analyses, concentrations of four markers were consistently higher in cases; sIL-2Rα, IP-10, sTNFR-2, MCP-1, and five were higher in controls; GM-CSF, IL-6, MIP-1β, sCRP, sGP130. In the adjusted models concentrations of four markers were significantly inversely associated with AIDS-KS risk including sGP130 (OR=0.14, 95% CI = 0.03–0.73, BAFF (OR=0.60, 95% CI =0.16–0.90), sCRP (OR=0.61, 95% CI = 0.43–0.87) and IL-6 (OR=0.51, 95% CI = 0.35–0.76). These results support a role for markers of immune activation and inflammation in AIDS-KS and may highlight pathways to be targeted for risk stratification or therapeutics.

Epidemiology of Castleman Disease

Castleman disease is a rare entity, including unicentric Castleman disease (UCD), human herpesvirus-8 plus Castleman disease (HHV-8+MCD), and idiopathic multicentric Castleman disease (iMCD). UCD is the most common at 16 per million person years and occurs at every age. HHV-8+MCD incidence varies widely, mostly affecting human immunodeficiency virus-positive men. iMCD is likely a more heterogeneous disease with an estimated incidence of 5 per million person years. Improved definitions should improve understanding of the epidemiology of Castleman disease and its subtypes.

Clinicopathological analysis of 114 cases of typical Kaposi's sarcoma in Xinjiang Uygur autonomous region, China

The present study aimed to investigate the clinicopathological features of cases of classic Kaposi's sarcoma (CKS) in Xinjiang Uygur Autonomous Region, China, and analyze its etiology and treatment. A total of 114 patients, who were clinicopathologically diagnosed with CKS at the First Affiliated Hospital of Xinjiang Medical University (Urumqi, China) between 1980 and 2015 were retrospectively analyzed. The clinicopathological features of CKS were summarized, and its demographic distribution, pathogenesis, etiology and treatment were examined. The results revealed that, among the 114 patients with CKS, 100 patients were men and 14 patients were women, with a respective ratio of 7:1. The average age of these patients was 57.5 years old, and 97 of the patients were from the Uygur Autonomous Region (85.1%). Among the 114 patients, 60 patients (52.6%) were from Southern Xinjiang, 50 patients (43.9%) were from Northern Xinjiang and four patients (3.5%) were from Eastern Xinjiang. It was found that CKS in the Uygur ethnic group of Xinjiang Uygur Autonomous Region had unique clinicopathological features. The occurrence of CKS in Xinjiang may be associated with human herpes virus 8 infection, ethnicity-based susceptibility and lifestyle.

Molecular Epidemiology of Kaposi's Sarcoma-Associated Herpes Virus, and Risk Factors in HIV-infected Patients in Tehran, 2014

Background

Kaposi’s sarcoma (KS) remains the most common malignancy among HIV-infected patients. Human herpesvirus type-8 (HHV-8) is regarded as the infectious etiological agent of Kaposi’s sarcoma (KSHV). Diagnostic procedures associated with KSHV are not routinely performed in HIV-infected subjects.

Objectives

The main objective of this study is to obtain information on KSHV epidemiology in Iranian HIV-infected individuals.

Patients and Methods

In the present cross-sectional study, 109 patients with established HIV infection, who visited a governmental and referral center for HIV screening in Tehran (Tehran west health center (TWHC)) between May 2014 and July 2015 were enrolled according to the convenience sample strategy. After peripheral blood collection, isolation of plasma and peripheral blood mononuclear cell (PBMC) compartments, DNA extraction was performed. KSHV DNA was analyzed by nested polymerase chain reaction (nested PCR) using primers from ORF-26 (virus minor capsid).

Results

Among all 109 HIV-infected patients, 67 (61.5%) were male, with an age range of 2 - 64 years (mean ± standard deviation 35.8 ± 13.3). KSHV DNA was found in PBMC and plasma samples of six (5.5%) and four (3.6%) patients, respectively.

Conclusions

This study revealed a considerable prevalence of KSHV DNA, during latent and lytic phases, among HIV-infected patients. Risk factors for KSHV infection acquisition and concurrent. 0+infection with HIV were also evaluated. Diagnosis of KSHV in the group could be helpful for prognosis of Kaposi’s sarcoma and clinical management.

Patterns of human herpesvirus-8 oral shedding among diverse cohorts of human herpesvirus-8 seropositive persons

Background

Human herpesvirus-8 (HHV-8), the etiologic agent of Kaposi sarcoma (KS), establishes lifelong latent infection with periodic lytic replication (“shedding”) at mucosal sites, especially the oropharynx. Patterns of HHV-8 shedding are not well understood, and require elucidation to better predict risk of HHV-8 related malignancies in those infected. We sought to characterize patterns of HHV-8 oropharyngeal shedding among diverse cohorts that enrolled HHV-8 seropositive persons.

Methods

We quantified HHV-8 oral shedding using PCR among HHV-8 seropositive persons who collected at least 14 days of oral swabs in 22 studies on 3 continents. We excluded persons taking antivirals during sampling or any prior use of antiretrovirals in those who were HIV-infected.

Results

248 participants were enrolled from the US, Peru, Cameroon, Uganda, and Kenya; 61 % were men, 58 % were HIV seropositive, and 16 % had KS. Overall, 3,123 of 10,557 samples (29.6 %) had HHV-8 detected. Quantity of virus shed was highly correlated with shedding rate, (ρ = 0.72, p < 0.0001). HHV-8 was detected in ≥1 sample in 55 % of participants with a median of 7 % of days in the US and Kenya, 0 % in Uganda and Peru, and 18 % in Cameroon. Median episode duration was three days, and episodes with high median quantity lasted longer (42 vs 3 days, p < 0.0001). In persons with multiple observations over time, 66 % of shedding rate variance was attributable to differences between individuals.

Conclusions

In HHV-8 infected individuals from diverse settings, oral mucosal shedding rate, quantity, and duration were correlated; individual shedding was highly variable. Studies are needed to determine factors accounting for between-person variation and the relationship of HHV-8 shedding to development of associated diseases.

Prevalence of Kaposi's sarcoma associated herpesvirus among men attending sexually transmitted infections clinics in Anhui, China

Kaposi's sarcoma-associated herpesvirus (KSHV) may be transmitted via sexual contacts, but limited information is available on KSHV infection status among sexually transmitted infection (STI) patients in China. The main objective of the present study was to determine the KSHV seroprevalence and its risk factors among male STI patients. A cross-sectional survey was conducted in three prefectures of Anhui province, China, between June and September 2013. A total of 1,600 male patients who visited an STI clinic were invited, and 1,372 participated in the study. Data were abstracted from the medical records for all the patients. Blood samples were collected and tested for antibodies to KSHV, HIV, HCV, and syphilis. Factors associated with KSHV seropositivity were examined using multivariable logistic regression analysis. The overall prevalence of KSHV, HIV, HCV, and syphilis was 13.3%, 0.7%, 0.6%, and 12.5%, respectively. After adjusting for potential confounders, KSHV infection was significantly associated with ever having anal sex with men (19 out of 30 males, OR: 8.64, 95%CI: 1.92-38.79) and HIV infection (six out of nine HIV-positive individuals, OR: 8.39, 95%CI: 1.80-39.04). There were no significant associations of KSHV infection with drug use, heterosexual sex behaviors, syphilis, and HCV. Our finding has shown that a relatively moderate prevalence of KSHV was found among male STI patients. While an increased risk for KSHV infection was observed among participants with homosexual contacts. Routine KSHV testing is recommended for male individuals attending STI clinics.

Rapid regression of Kaposi's sarcoma of the hard palate under therapy with boosted elvitegravir-containing fixdose antiretroviral combination therapy

INTRODUCTION

Kaposi's sarcoma (KS) is a rare vascular tumor that may occur in a severe, rapidly progressive form, namely in HIV/AIDS patients. HIV-associated KS mainly affects the skin and mucous membranes.

CASE PRESENTATION

We report about an HIV-positive patient who presented with an exophytic growing tumor in the region of the hard palate and severe problems regarding his dental status. Histological examination revealed evidence of AIDS-related KS. Antiretroviral therapy initiation with elvitegravir/cobicistat/emtricitabine(FTC)/tenofovirdisoproxilfumarat (E/c/F/T-fix dose combination) resulted in rapid complete remission of the KS within 2 months.

CONCLUSION

In this case of a treatment-naive HIV-infected patient with coexisting KS, antiretroviral therapy with E/c/FTC/TDF was very well suited to achieve rapid complete remission of KS.

Dendritic cells: key players in human herpesvirus 8 infection and pathogenesis

Human herpesvirus 8 (HHV-8; Kaposi's sarcoma-associated herpesvirus) is an oncogenic gammaherpesvirus that primarily infects cells of the immune and vascular systems. HHV-8 interacts with and targets professional antigen presenting cells and influences their function. Infection alters the maturation, antigen presentation, and immune activation capabilities of certain dendritic cells (DC) despite non-robust lytic replication in these cells. DC sustains a low level of antiviral functionality during HHV-8 infection in vitro. This may explain the ability of healthy individuals to effectively control this virus without disease. Following an immune compromising event, such as organ transplantation or human immunodeficiency virus type 1 infection, a reduced cellular antiviral response against HHV-8 compounded with skewed DC cytokine production and antigen presentation likely contributes to the development of HHV-8 associated diseases, i.e., Kaposi's sarcoma and certain B cell lymphomas. In this review we focus on the role of DC in the establishment of HHV-8 primary and latent infection, the functional state of DC during HHV-8 infection, and the current understanding of the factors influencing virus-DC interactions in the context of HHV-8-associated disease.

Epidemiology and genetic variability of HHV-8/KSHV in Pygmy and Bantu populations in Cameroon

Background

Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8) is the causal agent of all forms of Kaposi sarcoma. Molecular epidemiology of the variable K1 region identified five major subtypes exhibiting a clear geographical clustering. The present study is designed to gain new insights into the KSHV epidemiology and genetic diversity in Cameroon.

Methodology/Principal Findings

Bantu and Pygmy populations from remote rural villages were studied. Antibodies directed against latent nuclear antigens (LANA) were detected by indirect immunofluorescence using BC3 cells. Peripheral blood cell DNAs were subjected to a nested PCR amplifying a 737 bp K1 gene fragment. Consensus sequences were phylogenetically analyzed. We studied 2,063 persons (967 females, 1,096 males, mean age 39 years), either Bantus (1,276) or Pygmies (787). The Bantu group was older (42 versus 35 years: P<10⁻⁴). KSHV anti-LANA seroprevalence was of 37.2% (768/2063), with a significant increase with age (P<10⁻⁴) but no difference according to sex. Seroprevalence, as well as the anti-LANA antibodies titres, were higher in Bantus (43.2%) than in Pygmies (27.6%) (P<10⁻⁴), independently of age. We generated 29 K1 sequences, comprising 24 Bantus and five Pygmies. These sequences belonged to A5 (24 cases) or B (five cases) subtypes. They exhibited neither geographical nor ethnic aggregation. A5 strains showed a wide genetic diversity while the B strains were more homogenous and belonged to the B1 subgroup.

Conclusion

These data demonstrate high KSHV seroprevalence in the two major populations living in Southern and Eastern Cameroon with presence of mostly genetically diverse A5 but also B K1 subtypes.

Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8) is the causal agent of one of the most frequent skin tumors found endemically or epidemically associated to HIV in Central and Eastern Africa. This highly variable virus tends to cluster geographically according to specific major subtypes. Its prevalence is high in that area and increases with age. Despite its association to all forms of Kaposi sarcoma and high prevalence described in some low income populations in Cameroon, KSHV arouses limited interest, and only few focused previous studies have looked into prevalence and modes of transmission, especially in families. Extended molecular epidemiology is unknown both in healthy individuals and in Kaposi patients, which led to looking for new insights among Bantu and Pygmy populations from rural villages in three regions of Cameroon sharing a quite similar living environment but yet genetically, socially, and culturally different. The present study is designed to describe variations of molecular subtypes in each of these population groups regarding their geography in rural areas of southern, central, and eastern Cameroon.

Seroprevalence of human herpesvirus-8 in HIV-1 infected and uninfected individuals in Cameroon

We evaluated the prevalence of HHV-8 antibodies in 516 plasma samples collected from HIV positive and negative patients from blood banks and urban areas of Cameroon. Among HIV-1 positive samples, HHV-8 seropositivity rate was 61% based on combined reactivity using both ELISA and IFA techniques. HIV negative samples showed 62% seropositivity rate for HHV-8 antibodies. Our results indicate a high HHV-8 prevalence rate in both HIV infected and uninfected individuals in Cameroon.

Illumination of murine gammaherpesvirus-68 cycle reveals a sexual transmission route from females to males in laboratory mice

Transmission is a matter of life or death for pathogen lineages and can therefore be considered as the main motor of their evolution. Gammaherpesviruses are archetypal pathogenic persistent viruses which have evolved to be transmitted in presence of specific immune response. Identifying their mode of transmission and their mechanisms of immune evasion is therefore essential to develop prophylactic and therapeutic strategies against these infections. As the known human gammaherpesviruses, Epstein-Barr virus and Kaposi's Sarcoma-associated Herpesvirus are host-specific and lack a convenient in vivo infection model; related animal gammaherpesviruses, such as murine gammaherpesvirus-68 (MHV-68), are commonly used as general models of gammaherpesvirus infections in vivo. To date, it has however never been possible to monitor viral excretion or virus transmission of MHV-68 in laboratory mice population. In this study, we have used MHV-68 associated with global luciferase imaging to investigate potential excretion sites of this virus in laboratory mice. This allowed us to identify a genital excretion site of MHV-68 following intranasal infection and latency establishment in female mice. This excretion occurred at the external border of the vagina and was dependent on the presence of estrogens. However, MHV-68 vaginal excretion was not associated with vertical transmission to the litter or with horizontal transmission to female mice. In contrast, we observed efficient virus transmission to naïve males after sexual contact. In vivo imaging allowed us to show that MHV-68 firstly replicated in penis epithelium and corpus cavernosum before spreading to draining lymph nodes and spleen. All together, those results revealed the first experimental transmission model for MHV-68 in laboratory mice. In the future, this model could help us to better understand the biology of gammaherpesviruses and could also allow the development of strategies that could prevent the spread of these viruses in natural populations.

Epstein-Barr virus and the Kaposi's Sarcoma-associated Herpesvirus are two human gammaherpesviruses which are linked to the development of several cancers. Efficient control of these infections is therefore of major interest, particularly in some epidemiological circumstances. These viruses are however host-specific and cannot be experimentally studied in vivo. The identification of a closely related viral species, called Murid herpesvirus 4 with the main strain called murine gammaherpesvirus-68 (MHV-68), in wild rodents opened new horizons to the study of gammaherpesvirus biology. Surprisingly, despite 30 years of research, MHV-68 transmission had never been observed in captivity. In this study, using in vivo imaging, we showed that MHV-68 is genitally excreted after latency establishment in intranasally infected female mice. This allowed us to observe, for the first time, sexual transmission of MHV-68 between laboratory mice. In the future, this model should be important to better understand the biology of gammaherpesviruses and should also allow the development of strategies that could prevent the spread of these viruses in natural populations.

Kaposi's sarcoma in pregnancy after initiation of highly active antiretroviral therapy: a manifestation of immune reconstitution syndrome

A case of Kaposi's sarcoma (KS) presenting as an immune reconstitution inflammatory syndrome in pregnancy with conservative management is reported. Successful outcomes for mother and baby were achieved. HIV was diagnosed at antenatal booking and highly active antiretroviral therapy commenced at 20 weeks. Multiple lymphadenopathies developed two months later. Excision biopsy of a node confirmed KS. In the absence of advanced disease, she was managed conservatively until delivery. The placenta showed no evidence of KS or human herpes virus 8 (HHV-8). The baby had negative HIV and HHV-8 polymerase chain reaction tests at zero, six and 12 weeks of life. Six months postpartum, the KS had regressed and HHV-8 viral load was undetectable.

Kaposi's Sarcoma: clinical and pathological aspects in patients seen at the Hospital Universitário Cassiano Antônio Moraes - Vitória - Espírito Santo - Brazil

BACKGROUND: Kaposi's sarcoma is a neoplasm of endothelial origin that is divided into four distinct types according to the clinical characteristics and the affected population: Classic (in elder men of Jewish or Mediterranean origin); Epidemic (in patients affected by AIDS); Endemic (in black African men) and Iatrogenic (in patients under immunosuppressive regimens). Human herpesvirus 8 infection is essential but not sufficient for the sarcoma development. OBJECTIVE: To describe the epidemiological, clinical and histopathological aspects of patients with KS seen at the Dermatology Clinic -Cassiano Antônio Moraes University Hospital - Federal University of Espirito Santo, Vitória - ES. METHODS: A descriptive and retrospective study based on clinical charts of patients with KS seen at the Dermatology Clinic from 1986 to 2009. RESULTS: The majority of the 15 cases were male patients (93,3%) and white (60%). Epidemic Kaposi's sarcoma occurred in 80%, and the Classic form in 20%, with no cases in the Endemic or Iatrogenic groups. All the histopatho logical exams of the cutaneous lesions were reviewed and a proliferation of fusiform cells, extravasated erythrocytes and vascular rifts among the largest vessels, assuming the "vessels in vessels" typical aspect, were seen. CONCLUSION: The number of cases of Kaposi's Sarcoma was linear throughout the years of the study, especially of the epidemic form, although the incidence and prevalence of AIDS increased in the state of Espírito Santo. Therefore, if we consider the relation between KS and AIDS, a decreasing line of Kaposi's sarcoma could be seen, especially after the introduction of HAART.

A major locus on chromosome 3p22 conferring predisposition to human herpesvirus 8 infection

Infection with human herpesvirus 8 (HHV-8), the etiological agent of Kaposi's sarcoma, has been shown to display strong familial aggregation, in countries in which HHV-8 infection is endemic. We investigated 40 large families (608 subjects aged one to 88 years) living in an isolated area of Cameroon in which HHV-8 is highly endemic. We performed a two-step genetic analysis for HHV-8 infection status (HHV-8+/HHV-8- determined by immunofluorescence) consisting of an initial segregation analysis followed by a model-based genome-wide linkage analysis. Overall HHV-8 seroprevalence was 60%, increasing with age. Segregation analysis provided strong evidence for a recessive major gene conferring predisposition to HHV-8 infection. This gene is predicted to have a major effect during childhood, with almost all homozygous predisposed subjects (∼7% of the population) becoming infected by the age of 10. Linkage analysis was carried out on the 15 most informative families, corresponding to 205 genotyped subjects. A single region on chromosome 3p22 was significantly linked to HHV-8 infection (LOD score=3.83, P=2.0 × 10(-5)). This study provides the first evidence that HHV-8 infection in children in endemic areas has a strong genetic basis involving at least one recessive major locus on chromosome 3p22.

Viral interferon regulatory factors are critical for delay of the host immune response against rhesus macaque rhadinovirus infection

Kaposi's sarcoma-associated herpesvirus (KSHV) and the closely related gamma-2 herpesvirus rhesus macaque (RM) rhadinovirus (RRV) are the only known viruses to encode viral homologues of the cellular interferon (IFN) regulatory factors (IRFs). Recent characterization of a viral IRF (vIRF) deletion clone of RRV (vIRF-knockout RRV [vIRF-ko RRV]) demonstrated that vIRFs inhibit induction of type I and type II IFNs during RRV infection of peripheral blood mononuclear cells. Because the IFN response is a key component to a host's antiviral defenses, this study has investigated the role of vIRFs in viral replication and the development of the immune response during in vivo infection in RMs, the natural host of RRV. Experimental infection of RMs with vIRF-ko RRV resulted in decreased viral loads and diminished B cell hyperplasia, a characteristic pathology during acute RRV infection that often develops into more severe lymphoproliferative disorders in immune-compromised animals, similar to pathologies in KSHV-infected individuals. Moreover, in vivo infection with vIRF-ko RRV resulted in earlier and sustained production of proinflammatory cytokines and earlier induction of an anti-RRV T cell response compared to wild-type RRV infection. These findings reveal the broad impact that vIRFs have on pathogenesis and the immune response in vivo and are the first to validate the importance of vIRFs during de novo infection in the host.

In vivo function of the murid herpesvirus-4 ribonucleotide reductase small subunit

The difficulty of eliminating herpesvirus carriage makes host entry a key target for infection control. However, its viral requirements are poorly defined. Murid herpesvirus-4 (MuHV-4) can potentially provide insights into gammaherpesvirus host entry. Upper respiratory tract infection requires the MuHV-4 thymidine kinase (TK) and ribonucleotide reductase large subunit (RNR-L), suggesting a need for increased nucleotide production. However, both TK and RNR-L are likely to be multifunctional. We therefore tested further the importance of nucleotide production by disrupting the MuHV-4 ribonucleotide reductase small subunit (RNR-S). This caused a similar attenuation to RNR-L disruption: despite reduced intra-host spread, invasive inoculations still established infection, whereas a non-invasive upper respiratory tract inoculation did so only at high dose. Histological analysis showed that RNR-S⁻, RNR-L⁻ and TK⁻ viruses all infected cells in the olfactory neuroepithelium but unlike wild-type virus then failed to spread. Thus captured host nucleotide metabolism enzymes, up to now defined mainly as important for alphaherpesvirus reactivation in neurons, also have a key role in gammaherpesvirus host entry. This seemed to reflect a requirement for lytic replication to occur in a terminally differentiated cell before a viable pool of latent genomes could be established.

The lytic activation of KSHV during keratinocyte differentiation is dependent upon a suprabasal position, the loss of integrin engagement, and calcium, but not the interaction of cadherins

We previously found that KSHV (HHV-8) lytic activation occurs during differentiation of oral keratinocytes in organotypic raft cultures. To further investigate the spatial and temporal aspects of KSHV lytic activation and the roles of integrins, cadherins, and calcium, we used rKSHV.219-infected primary oral keratinocytes in submerged, suspension, and direct suprabasal plating, models of differentiation. We found that early keratinocyte differentiation did not activate lytic KSHV in cells attached to a substratum, with activation only occurring in suprabasal cells. Temporally, KSHV lytic expression occurred between the expression of early and late differentiation markers. Keratinocytes differentiated in suspension culture, which mimics substratum loss that occurs with stratification, activated lytic KSHV. This lytic activation was inhibited by integrin engagement, showing that integrins are a control point for KSHV reactivation. A role for cadherins was not found. Elevated extracellular calcium was necessary, but not sufficient, for lytic activation.

Update on HHV-8-Associated Malignancies

The human herpesvirus 8 (HHV-8) is the oncogenic virus associated with Kaposi's sarcoma (KS) and lymphoproliferative disorders, namely, primary effusion lymphoma and multicentric Castleman's disease. KS is among the most common malignancies seen in HIV-infected patients despite the decreased incidence of KS in the era of highly active antiretroviral therapy. Advances in molecular pathology reveal HHV-8 tumorigenesis is mediated through molecular mimicry wherein viral-encoded proteins can activate several cellular signaling cascades while evading immune surveillance. This knowledge has led to the evolution of multiple therapeutic strategies against specific molecular targets. Many such therapeutic modalities have shown activity, but none have proven to be curative. Identifying possible prognostic factors is another active area of research. This review summarizes the recent developments in the fields of virus transmission, molecular biology, and treatment of HHV-8-related neoplasms.

Vaccines to prevent infections by oncoviruses

It has been estimated that viruses are etiological agents in approximately 12% of human cancers. Most of these cancers can be attributed to infections by human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), Epstein-Barr virus (EBV), and Kaposi's sarcoma-associated herpesvirus (KSHV). Prophylactic vaccines against other pathogenic viruses have an excellent record as public health interventions in terms of safety, effectiveness, and ability to reach economically disadvantaged populations. These considerations should prompt efforts to develop and implement vaccines against oncoviruses. Safe and effective HBV and HPV vaccines, based on virus-like particles, are commercially available, and the major focus is now on vaccine delivery, especially to low-resource settings. HCV and EBV vaccines are under active development, but few clinical trials have been conducted, and none of the candidate vaccines has proven to be sufficiently effective to warrant commercialization. Efforts to develop KSHV vaccines have been more limited.

Oral sexual behaviors associated with prevalent oral human papillomavirus infection

Oral human papillomavirus (HPV) infection is a cause of oropharyngeal cancer. We investigated whether sexual behaviors that elevated the odds of oropharyngeal cancer developing in a case-control study similarly elevated the odds of oral HPV infection developing among control patients. HPV infection was detected in 4.8% of 332 control patients from an outpatient clinic and in 2.9% of 210 college-aged men (age range, 18-23 years). Among control patients, the odds of infection developing independently increased with increases in the lifetime number of oral (P = .007, for trend) or vaginal sex partners (P = .003, for trend). Among college-aged men, the odds of oral HPV infection developing increased with increases in the number of recent oral sex partners (P = .046, for trend) or open-mouthed kissing partners (P = .023, for trend) but not vaginal sex partners. Oral sex and open-mouthed kissing are associated with the development of oral HPV infection.

Screening colonies of pooled ORFeomes (SCOOP): a rapid and efficient strategy for expression screening ORFeomes in Escherichia coli

We have designed and evaluated a novel strategy for screening large gene collections available as GATEWAY-adapted ORFeomes for soluble recombinant overexpression in Escherichia coli, called "Screening Colonies of ORFeome Pools" (SCOOP). From a large gene collection we could, without expensive multi-well based cloning and expression screening, determine which targets were suitable for large-scale expression and purification. Normalized bacterial overnight cultures of an ORF collection of entry clones derived from the Kaposi's sarcoma associated herpesvirus (KSHV) were pooled and used for the isolation of plasmid DNA. The resulting ORF library was subcloned into a prokaryotic expression vector in a single recombination reaction and was subsequently screened with the colony filtration (CoFi) blot for soluble recombinant overexpression in E. coli. ORFs determined to express soluble recombinant proteins were identified by sequencing and analysed by small-scale IMAC and SDS-PAGE. As a reference, we subcloned all ORFs individually using a traditional multi-well based procedure and screened them for soluble expression. Our results show that the two processes have a similar efficiency as 23 and 25 out of 74 assessable clones were identified as soluble expressers using SCOOP and the traditional multi-well procedure, respectively. Because SCOOP minimises costs for cloning and expression screening, it constitutes an interesting alternative for establishing expression of large gene collections. SCOOP also allows affordable screening in alternative vectors, expression strains and physical conditions, which is challenging in large-scale protein production programs. With this strategy in hand success rates for future proteome-wide protein production efforts can be significantly increased.

Human herpesvirus 8 seroprevalence among Tobago women and the role of sexual lifestyle behavior

Human herpesvirus 8 (HHV-8) infection is present in 22.9% of Tobago men. However, seroprevalence and modes of transmission of HHV-8 among Tobago women are not known. HHV-8 seropositivity rates in Tobago women were examined and compared rates to Tobago men of similar ages. To assess possible modes of transmission, sexual behavior among Tobago women was examined to determine its association with HHV-8 seropositivity. A cross-sectional study was conducted in 213 Tobago women, ages 18-65 years, who participated in the Tobago Cervical and Oral Cancer Screening Study. HHV-8 seropositivity was determined by a monoclonal immunofluorescence assay. Age-specific rates were compared to those previously observed in men. Logistic regression analyses were performed to determine the association between HHV-8 seropositivity and sexual behavior among the women. HHV-8 seroprevalence among Tobago women was 14.1% (95% CI, 10-19%), with no significant difference with men of similar age (P-value = 0.741). Age <or=17 years at first sexual intercourse was found to have a minimal significant association with HHV-8 seropositivity (OR = 2.51, 95% CI = 1.09-5.78) in women. HHV-8 age-specific rates were similar between genders. Sexual activity may not be a major contributor to HHV-8 infection among Tobago women.

In vitro and in vivo human herpesvirus 8 infection of placenta

Herpesvirus infection of placenta may be harmful in pregnancy leading to disorders in fetal growth, premature delivery, miscarriage, or major congenital abnormalities. Although a correlation between human herpesvirus 8 (HHV-8) infection and abortion or low birth weight in children has been suggested, and rare cases of in utero or perinatal HHV-8 transmission have been documented, no direct evidence of HHV-8 infection of placenta has yet been reported. The aim of this study was to evaluate the in vitro and in vivo susceptibility of placental cells to HHV-8 infection. Short-term infection assays were performed on placental chorionic villi isolated from term placentae. Qualitative and quantitative HHV-8 detection were performed by PCR and real-time PCR, and HHV-8 proteins were analyzed by immunohistochemistry. Term placenta samples from HHV-8-seropositive women were analyzed for the presence of HHV-8 DNA and antigens. In vitro infected histocultures showed increasing amounts of HHV-8 DNA in tissues and supernatants; cyto- and syncitiotrophoblasts, as well as endothelial cells, expressed latent and lytic viral antigens. Increased apoptotic phenomena were visualized by the terminal deoxynucleotidyl transferase-mediated deoxyuridine nick end-labeling method in infected histocultures. Ex vivo, HHV-8 DNA and a latent viral antigen were detected in placenta samples from HHV-8-seropositive women. These findings demonstrate that HHV-8, like other human herpesviruses, may infect placental cells in vitro and in vivo, thus providing evidence that this phenomenon might influence vertical transmission and pregnancy outcome in HHV-8-infected women.

Hantavirus RNA in saliva from patients with hemorrhagic fever with renal syndrome

Person-to-person transmission may occur through saliva.

Hantaviruses cause 2 zoonotic diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome. Infection is usually initiated after inhalation of virus-contaminated rodent excreta. In addition to the zoonotic infection route, growing evidence suggests person-to-person transmission of Andes virus. For this reason, we studied whether saliva from HFRS patients contained hantavirus. During an outbreak in northern Sweden of nephropathia epidemica (NE), a milder form of hemorrhagic fever with renal syndrome, we collected saliva and plasma from 14 hospitalized NE patients with verified Puumala virus (PUUV) infection. PUUV RNA was detected in saliva from 10 patients (range 1,530–121,323 PUUV RNA copies/mL) by quantitative reverse transcription–PCR. The PUUV S-segment sequences from saliva and plasma of the same patients were identical. Our data show that hantavirus RNA could be detected in human saliva several days after onset of disease symptoms and raise the question whether interhuman transmission of hantavirus may occur through saliva.

Persistent gammaherpesvirus replication and dynamic interaction with the host in vivo

Gammaherpesviruses establish life-long persistency inside the host and cause various diseases during their persistent infection. However, the systemic interaction between the virus and host in vivo has not been studied in individual hosts continuously, although such information can be crucial to control the persistent infection of the gammaherpesviruses. For the noninvasive and continuous monitoring of the interaction between gammaherpesvirus and the host, a recombinant murine gammaherpesvirus 68 (MHV-68, a gammaherpesvirus 68) was constructed to express a firefly luciferase gene driven by the viral M3 promoter (M3FL). Real-time monitoring of M3FL infection revealed novel sites of viral replication, such as salivary glands, as well as acute replication in the nose and the lung and progression to the spleen. Continuous monitoring of M3FL infection in individual mice demonstrated the various kinetics of transition to different organs and local clearance, rather than systemically synchronized clearance. Moreover, in vivo spontaneous reactivation of M3FL from latency was detected after the initial clearance of acute infection and can be induced upon treatment with either a proteasome inhibitor Velcade or an immunosuppressant cyclosporine A. Taken together, our results demonstrate that the in vivo replication and reactivation of gammaherpesvirus are dynamically controlled by the locally defined interaction between the virus and the host immune system and that bioluminescence imaging can be successfully used for the real-time monitoring of this dynamic interaction of MHV-68 with its host in vivo.