KSHV genotypes A and C are more frequent in Kaposi sarcoma lesions from Brazilian patients with and without HIV infection, respectively

Introduction of human gammaherpesvirus 8 genotypes A, B, and C into Brazil from multiple geographic regions

Variations in the open reading frame (ORF) K1 gene sequence of human gammaherpesvirus 8 (HHV-8) has led to the identification of 6 major genotypic clades (A, B, C, D, E, and F) in specimens isolated from around the world. These clades exhibit clear clustering among individuals in different ethnic groups and from different geographic regions. The human population of Brazil varies greatly in ethnicity because of multiple immigration events from Africa, Europe, Asia, and indigenous communities. However, there is scant information about the HHV-8 genotypes currently circulating in Brazil. Here, we describe HHV-8 genotypic diversity in isolates from Brazilian HIV-infected patients living with Kaposi's sarcoma (KS) by analysis of the complete ORF-K1 region. We also identified the most likely geographic origins of these different Brazilian genotypes. We extracted HHV-8 DNA (24 positive samples) from individuals with HIV/KS from the states of São Paulo and Rio de Janeiro, amplified the ORF-K1 gene using nested PCR (about 870 base pairs), performed sequencing and phylogenetic analysis, and then calculated the mean genetic distances of Brazilian sequences from sequences in other regions of the world (523 sequences analyzed). Phylogenetic analysis showed that genotypes C, A, and B were present in 45.8 %, 29.2 % and 25 % of the isolates from Brazil, respectively. These isolates grouped into separate clades, rather than a single monophyletic cluster. Mean genetic distance analyses suggested that these genotypes were introduced into the Brazil multiple times from different geographical regions. HHV-8/A isolates appear to be from Ukraine, Russia, and the Tartar ethnic group; HHV-8/B isolates appear to be from Congo and Democratic Republic of the Congo; and HHV-8/C isolates appear to be from Australia, Algeria, England, and French Guiana. These results contribute to a better understanding of the genetic diversity and origins of HHV-8 strains circulating in Brazil, and will provide a foundation for further epidemiological and evolutionary studies of HHV-8.

K1 gene transformation activities in AIDS-related and classic type Kaposi's sarcoma: Correlation with clinical presentation

Kaposi's sarcoma-associated herpesvirus (KSHV) causes both AIDS-related Kaposi's sarcoma (KS) and classic KS, but their clinical presentations are different, and respective mechanisms remain to be elucidated. The KSHV K1 gene is reportedly involved in tumorigenesis through the immunoreceptor tyrosine-based activation motif (ITAM). Since we found the sequence variations in the K1 gene of KSHV isolated from AIDS-related KS and classic KS, we hypothesized that the transformation activity of the K1 gene contributes to the different clinical presentations. To evaluate our hypothesis, we compared the transformation activities of the K1 gene between AIDS-related KS and classic KS. We also analyzed ITAM activities and the downstream AKT and NF-κB. We found that the transformation activity of AIDS-related K1 was greater than that of classic K1, and that AIDS-related K1 induced higher ITAM activity than classic K1, causing more potent Akt and NF-κB activities. K1 downregulation by siRNA in AIDS-related K1 expressing cells induced a loss of transformation properties and decreased both Akt and NF-κB activities, suggesting a correlation between the transformation activity of K1 and ITAM signaling. Our study indicates that the increased transformation activity of AIDS-related K1 is associated with its clinical aggressiveness, whereas the weak transformation activity of classic type K1 is associated with a mild clinical presentation and spontaneous regression. The mechanism of spontaneous regression of classic KS may provide new therapeutic strategy to cancer.

Human herpesvirus 8 DNA detection and variant analysis in patients with multiple sclerosis

Several studies reported a complex interplay between viral infections and neural cells leading to multiple sclerosis. A role for some viral infections has been proposed in MS. In this study, DNA sequences of human herpesvirus 8 (HHV-8) were searched in the peripheral blood of 54 patients with multiple sclerosis and 130 healthy subjects using nested-PCR assay to amplify ORF26 locus. Furthermore, HHV-8 positive samples were subjected to a nested-PCR to amplify K1 gene of HHV-8 followed by direct nucleotide sequencing. HHV-8 genome was detected in 18.5% (10/54) and 3% (4/130) of MS patients and controls, respectively, and the difference reached statistically significant level (P = 0.0017). Genotyping analysis revealed that genotype C was common (88.9%) in all study subjects, followed by genotype A. Our results showed higher detection of HHV-8 DNA in MS patients than control group.

Diversity of human herpesvirus 8 genotypes in patients with AIDS and non-AIDS associated Kaposi's sarcoma, Castleman's disease and primary effusion lymphoma in Argentina

HHV-8 genotypes are distributed heterogeneously worldwide. The variable K1 gene and the conserved ORF26E region serve to genotype. The aim of the study was to characterize HHV-8 isolates from patients with AIDS, classical, and iatrogenic KS, primary effusion lymphoma and Castleman's disease and one organ donor from Argentina by analysis of ORFK1 and ORF26E regions. DNA was extracted from fresh or paraffin embedded biopsies, blood, and saliva samples and submitted to HHV-8 PCR. Phylogenetic analyses of ORFK1 showed that subtypes C (C1, C2, and C3), B1 and A (A1, A2, and A3) were present in 70.8%, 16.7%, and 12.5% of cases, respectively. Analyses of ORF26E fragment revealed that most strains (45.8%) were subtype A/C while the remaining fall into K, J, B2, R, and D subtypes. Linkage between ORFK1-ORF26E subtypes corresponded to reported relationships, except for one strain that clustered with B1 (K1 African) and D (ORF26E Asian-Pacific) subtypes. This research reveals predominance of subtype C, a broad spectrum of HHV-8 genotypes and reports the first isolation of the African B genotype in Argentina.

Kaposi's Sarcoma-Associated Herpesvirus: Epidemiology and Molecular Biology

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as Human herpesvirus 8 (HHV-8), is a member of the lymphotropic gammaherpesvirus subfamily and a human oncogenic virus. Since its discovery in AIDS-associated KS tissues by Drs. Yuan Chang and Patrick Moore, much progress has been made in the past two decades. There are four types of KS including classic KS, endemic KS, immunosuppressive therapy-related KS, and AIDS-associated KS. In addition to KS, KSHV is also involved in the development of primary effusion lymphoma (PEL) and certain types of multicentric Castleman's disease. KSHV manipulates numerous viral proteins to promote the progression of angiogenesis and tumorigenesis. In this chapter, we review the epidemiology and molecular biology of KSHV and the mechanisms underlying KSHV-induced diseases.

Molecular typing of human herpesvirus 8 among HIV positive in comparison to HIV-negative individuals in Iran

It is still unclear whether different HHV-8 genotypes may have different pathogenic and tumorigenic properties associated with a diverse rate of disease progression. In some areas where genotype C was found to be prominent among classic KS patients, genotype A was shown to be more frequent among AIDS-associated KS patients. Genotype C was previously reported to be widespread in Iran, with genotype A being less frequent among patients with classic KS although no data are available with regards to the HHV-8 genotyping among Iranian HIV-infected patients. In order to analyze HHV-8 genotypes (ORF K1), six HIV-infected patients (with or without KS), and 22 HIV-negative subjects (classic/iatrogenic KS patients and IVDUs) were investigated using nested PCR. Genotype A was detected more frequently among HIV-infected patients with or without KS (three out of six) whereas genotype C was found more common among HIV-negative subjects including classic/iatrogenic KS patients and IVDSs (21 out of 22), and this difference was statistically significant (P = 0.044). In conclusion, our data further support the dominancy of HHV-8 genotype C in Iranian general population. Moreover, genotype A was more common among HIV-infected patients with or without KS. J. Med. Virol. 89:703-709, 2017. © 2016 Wiley Periodicals, Inc.

Genotypic distribution of HHV-8 in AIDS individuals without and with Kaposi sarcoma: Is genotype B associated with better prognosis of AIDS-KS?

AIDS-associated Kaposi's sarcoma (AIDS-KS) caused by human herpes virus 8 (HHV-8) is the most severe and resistant form of KS tumor. Our aim was to verify whether there is an association between HHV-8 variability and development of AIDS-KS in Brazil by comparing the HHV-8 variability between individuals without and with KS. Saliva samples and blood, when available, were analyzed by polymerase chain reaction (PCR) techniques for detection of the fragments of ORF K1 of HHV-8, which were then genotyped and analyzed regarding the genetic variability. Our study described 106 positive cases for HHV-8 in the saliva from 751 AIDS patients without previous KS. In addition, we performed a phylogenetic analysis of HHV-8 in 34 of the 106 AIDS patients without KS and in 33 of the 37 patients with active KS. The distribution of HHV-8 genotypes A, B, C, and F in AIDS individuals was indistinguishable by comparing non-KS and KS groups, as well as regarding ethnicity. Considering the KS group, genotype B was associated with better prognosis of KS tumor. Interestingly, we found a particular profile of diversity within clade C and 2 recombinant patterns of HHV-8 in the saliva of AIDS individuals without KS. We emphasize the need to achieve standard genotyping protocol for ORF K1 amplification, thus allowing for substantial detection of HHV-8 variants. Our findings can shed light on the role of HHV-8 variability in the pathogenesis of AIDS-KS.

Case Report: Pulmonary Kaposi Sarcoma in a non-HIV patient

Kaposi Sarcoma (KS) is an angioproliferative tumor associated with human herpes virus 8 (HHV-8).  Often known as one of the acquired immunodeficiency syndrome (AIDS)-defining skin diseases, pulmonary involvement in KS has only been discussed in a handful of case reports, rarely in a non-HIV patient. Herein we report the case of a 77 year-old- male who presented with a 6-week history of progressive dyspnea on exertion accompanied by productive cough of yellow sputum and intermittent hemoptysis. His past medical history was significant for Non-Hodgkin's Follicular B-Cell Lymphoma (NHL). Patient also had biopsy-confirmed cutaneous KS. His physical exam was notable for a 2cm firm, non-tender, mobile right submandibular lymph node.  Lungs were clear to auscultation. He had multiple violet non-tender skin lesions localized to the lower extremities. CT scan of the chest showed numerous nodular opacities and small pleural effusions in both lungs. A thoracenthesis was performed, showing sero-sanguineous exudative effusions. Histopathology failed to demonstrate malignant cells or lymphoma. A subsequent bronchoscopy revealed diffusely hyperemic, swollen mucosa of the lower airways with mucopurulent secretions. Bronchoalveolar lavage PCR for HHV-8 showed 5800 DNA copies/mL.  It was believed that his pulmonary symptoms were likely due to disseminated KS.  This case illustrates the potential for significant lung injury from KS. It also demonstrates the use of PCR for HHV-8 to diagnose KS in a bronchoalveolar lavage sample in a case when bronchoscopic biopsy was not safe. Furthermore, this case is unique in that the patient did not match the typical KS subgroups as HIV infection and other immune disorders were ruled out. Recognition of this syndrome is critical to the institution of appropriate therapy. As such, this case should be of interest to a broad readership across internal medicine including the specialties of Pulmonology and Critical Care.

Genetic diversity of HHV8 subtypes in South Africa: A5 subtype is associated with extensive disease in AIDS-KS

Human herpes virus 8 (HHV8) is the etiological agent of all forms of Kaposi's sarcoma (KS). Six major subtypes (A-F), based on genetic variability of open reading frame (ORF)-K1, have been identified. Numerous studies point to differing tumorigenic and pathogenic properties of the HHV8 subtypes. The study objectives were to determine the HHV8 subtypes and their prevalence in a cohort of clinical and histologically confirmed KS in Cape Town, South Africa, and analyze associations between the different subtypes and clinical presentation of KS. Clinical records were prospectively reviewed to extract clinical presentation; demographic data were retrospectively collected and tissue biopsies were taken for ORF-K1 subtyping. Eighty six patients were subtyped; 81 AIDS (acquired immune deficiency syndrome)-KS and 5 African endemic-KS. Subtype A5 (42/86) and B2 (16/86) predominated. B1, B3, A1 and A4 subtypes were identified in 10/86, 9/86, 4/86 and 1/86 patients, respectively. A5 and B subtypes were found in African blacks and individuals of mixed ancestry, while subtypes A1 and A4 were found only in whites and individuals of mixed ancestry. Subtype A5 was associated with >10 KS lesions at presentation in the AIDS cohort (adjusted OR: 3.13; CI: 1.02-9.58). Subtypes A1 and A4 combined were less likely to be associated with poor risk tumor extension (P = 0.031) and A1 was associated with lower likelihood of lower limb involvement (P = 0.019). In conclusion, these results indicate that subtype A5 and B predominate in South Africa and A5 may be associated with more extensive disease.

Coupled transcriptome and proteome analysis of human lymphotropic tumor viruses: insights on the detection and discovery of viral genes

Background

Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are related human tumor viruses that cause primary effusion lymphomas (PEL) and Burkitt's lymphomas (BL), respectively. Viral genes expressed in naturally-infected cancer cells contribute to disease pathogenesis; knowing which viral genes are expressed is critical in understanding how these viruses cause cancer. To evaluate the expression of viral genes, we used high-resolution separation and mass spectrometry coupled with custom tiling arrays to align the viral proteomes and transcriptomes of three PEL and two BL cell lines under latent and lytic culture conditions.

Results

The majority of viral genes were efficiently detected at the transcript and/or protein level on manipulating the viral life cycle. Overall the correlation of expressed viral proteins and transcripts was highly complementary in both validating and providing orthogonal data with latent/lytic viral gene expression. Our approach also identified novel viral genes in both KSHV and EBV, and extends viral genome annotation. Several previously uncharacterized genes were validated at both transcript and protein levels.

Conclusions

This systems biology approach coupling proteome and transcriptome measurements provides a comprehensive view of viral gene expression that could not have been attained using each methodology independently. Detection of viral proteins in combination with viral transcripts is a potentially powerful method for establishing virus-disease relationships.