Extensive oral shedding of human herpesvirus 8 in a renal allograft recipient

Intra-host changes in Kaposi sarcoma-associated herpesvirus genomes in Ugandan adults with Kaposi sarcoma

Intra-host tumor virus variants may influence the pathogenesis and treatment responses of some virally-associated cancers. However, the intra-host variability of Kaposi sarcoma-associated herpesvirus (KSHV), the etiologic agent of Kaposi sarcoma (KS), has to date been explored with sequencing technologies that possibly introduce more errors than that which occurs in the viral population, and these studies have only studied variable regions. Here, full-length KSHV genomes in tumors and/or oral swabs from 9 Ugandan adults with HIV-associated KS were characterized. Furthermore, we used deep, short-read sequencing using duplex unique molecular identifiers (dUMI)–random double-stranded oligonucleotides that barcode individual DNA molecules before library amplification. This allowed suppression of PCR and sequencing errors to ~10⁻⁹/base as well as afforded accurate determination of KSHV genome numbers sequenced in each sample. KSHV genomes were assembled de novo, and rearrangements observed were confirmed by PCR and Sanger sequencing. 131-kb KSHV genome sequences, excluding major repeat regions, were successfully obtained from 23 clinical specimens, averaging 2.3x10⁴ reads/base. Strikingly, KSHV genomes were virtually identical within individuals at the point mutational level. The intra-host heterogeneity that was observed was confined to tumor-associated KSHV mutations and genome rearrangements, all impacting protein-coding sequences. Although it is unclear whether these changes were important to tumorigenesis or occurred as a result of genomic instability in tumors, similar changes were observed across individuals. These included inactivation of the K8.1 gene in tumors of 3 individuals and retention of a region around the first major internal repeat (IR1) in all instances of genomic deletions and rearrangements. Notably, the same breakpoint junctions were found in distinct tumors within single individuals, suggesting metastatic spread of rearranged KSHV genomes. These findings define KSHV intra-host heterogeneity in vivo with greater precision than has been possible in the past and suggest the possibility that aberrant KSHV genomes may contribute to aspects of KS tumorigenesis. Furthermore, study of KSHV with use of dUMI provides a proof of concept for utilizing this technique for detailed study of other virus populations in vivo.

Kaposi sarcoma (KS) is a leading cancer in sub-Saharan Africa and in persons with HIV co-infection. Kaposi sarcoma-associated herpesvirus (KSHV, also referred to as human herpesvirus-8, or HHV-8) is the etiologic agent of KS, but the factors that contribute to the development of KS, which occurs in only a small subset of infected individuals, remain largely unknown. While strain differences or mutations in other tumor viruses are known to affect the risk and progression of their associated cancers, whether genetic variation in KSHV is important to the natural history of KS is unclear. Most studies of KSHV diversity have only characterized ~4% of its 165-kb genome, and the observed variation in some studies is likely to have been impacted by PCR or cloning artifacts. To precisely define genomic diversity of KSHV in vivo, we evaluated full-length viral genomes (except the internal repeat regions) using a technique that greatly lowers sequencing error rates and thus measures genomic diversity much more accurately than previous studies. In addition, we extended our analyses to look for potential tumor-specific changes in the KSHV genomes by examining viruses in both tumor and non-tumor tissues. To these ends, we performed highly sensitive, single-molecule sequencing of whole KSHV genomes in paired KS tumors and oral swabs from 9 individuals with KS. We found that KSHV genomes were virtually identical within the 9 individuals, with no evidence of quasispecies formation or multi-strain infection. However, KSHV genome aberrations and gene-inactivating mutations were found to be common in KS tumors, often impacting the same genes and genomic regions across individuals. Whether theses mutations influence KS tumorigenesis or result from genomic instability commonly found in tumors warrants further study. Lastly, aberrant KSHV genomes were found to be shared by distinct tumors within individuals, suggesting the capacity of KS tumor cells to metastasize and seed new lesions.

Herpesviruses oral shedding and viremia in renal transplant recipients: A longitudinal study

BACKGROUND

The objective was to assess the oral shedding and viremia of human herpesviruses in renal transplant recipients.

METHODS

This is a cohort study in which the participants were examined in three different periods: the first within 24 hours before renal transplantation and the second and third ones 15-20 and 45-60 days after the transplantation. Mouthwash and blood samples were collected in each period and then submitted to screening for the presence of eight types of human herpesviruses by using multiplex PCR.

RESULTS

HSV-1 and EBV were more frequent in the saliva after renal transplantation, 15- to 20-day period after the transplant. EBV was found in the saliva of 26 (35.6%) patients before renal transplantation and in 56.2% and 46.6% of them, in the 15- to 20-day and 45- to 60-day periods after the transplant, respectively. High detection rates (75.3%-78.1%) were found for HHV-7 despite the lack of significant variations between the study periods. There was no concordance between herpesviruses oral shedding and viremia.

CONCLUSION

We concluded that the pattern of excretion of HSV-1 and EBV in saliva is changed immediately after renal transplantation, increasing in the 15- to 20-day period after the transplant surgery. No concordance between herpesviruses oral shedding and viremia was observed.

Periodontal disease and detection of human herpesviruses in saliva and gingival crevicular fluid of chronic kidney disease patients

BACKGROUND

Patients with chronic kidney disease (CKD) have inability to maintain the normal levels of protein metabolism products, blood pressure and hematocrit. Periodontal disease involves an inflammatory destructive process. Identification of opportunistic viruses is extremely important as they are associated with co-morbidities. The objective of this study was to analyse the presence of human herpesviruses in saliva and gingival crevicular fluid (GCF) from patients with CKD.

METHODS

One hundred and thirty one individuals were divided depending on the stage of CKD: Group 1 (clearance of creatinine > 75 mL/min) patients with no renal disease (n = 24); Group 2 (clearance of creatinine of 11-75 mL/min) patients with renal disease (n = 67); Group 3 (clearance of creatinine < 10 mL/min) patients on hemodialysis (n = 40). The parameters of periodontal disease were evaluated. The viral detection was assessed by PCR.

RESULTS

considering the three groups, the prevalence of herpes simplex virus 1 (HSV-1) were 9% in saliva and 5% in GCF; Epstein-Barr virus 36% in saliva and 39% in GCF; human cytomegalovirus (HCMV) 11% in GCF; varicella zoster virus 6% in saliva and 3% in GCF; of human herpesvirus-6 (HHV-6) 6% in saliva and 2% in GCF; and HHV-7 44% in saliva and 8% in GCF. Of these patients, 46.48% presented with severe periodontitis. A statistically significant association between HSV-1 and HCMV was found in hemodialysis patients and severe periodontitis was also more frequent among them.

CONCLUSION

These findings show the importance of evaluating the periodontal disease and detecting herpesviruses in patients with CKD as the inflammatory process observed in these clinical conditions may worsen the course of both periodontal disease and CKD.

Oral shedding of human herpesviruses in renal transplant recipients

OBJECTIVE

To describe the shedding profile of human herpesviruses in the saliva of renal transplant recipients.

METHODS

This is a prospective case-control study of 50 renal transplant recipients and control group of 50 individuals (non-transplanted and immunocompetent). Mouthwash samples were collected via oral rinse and then submitted to screening for the presence of eight types of herpesviruses by using multiplex PCR. Fisher's exact, chi-square, and Student t tests were used for statistical analysis, and the significance level was set at 5%.

RESULTS

The mean age of the study group was 49.42 ± 12.94 years, 28/50 (56%) were female, and the time elapsed after transplantation was 68.20 ± 67.19 months. Herpes simplex virus 1 (HSV-1) (P = 0.025) and Epstein-Barr virus (EBV) (P = 0.024) were, statistically, more excreted in the saliva of renal transplant recipients compared to control group. Gender (P = 1.00) and age (P = 0.563) did not influence the salivary shedding of herpesviruses in renal transplant recipients. Individuals who excreted varicella-zoster virus in saliva had a shorter mean time of transplantation (22:00 + 2.82 months) (P < 0.001).

CONCLUSION

Renal transplant recipients excreted herpesviruses more often than controls, especially HSV-1 and EBV, with salivary shedding of herpesviruses being more frequent in patients with recent kidney transplantation.

CLINICAL RELEVANCE

The present findings support other longitudinal studies evaluating the relationship between oral shedding of human herpesviruses and clinical presence of active infection and renal transplant failure.

Oral Kaposi Sarcoma in HIV-seronegative Saudi patient: Literature review and case report

Kaposi Sarcoma (KS) is an intermediate neoplasm affecting the endothelial cells of mucous membranes and skin. It arises most commonly among HIV-infected individuals. We present an intra-oral KS in an 80-year-old Saudi male patient, who is HIV-seronegative, non-immunosuppressed, and with no history of organ transplantation. The patient was treated with fractionated radiation therapy, and had no recurrence in the 48 months of follow-up. The clinical disease, histologic features, and treatment modality used, as well as the relative literature are presented in this paper.

Viral infections associated with oral cancers and diseases in the context of HIV: a workshop report

Human herpesviruses (HHVs) and human papillomavirus (HPV) are common in the general population and, in immunocompetent people, are mostly carried asymptomatically. However, once an individual becomes immunocompromised by age, illness or HIV infection these dormant viruses can manifest and produce disease. In HIV-positive patients, there is an increased risk of disease caused by HHVs and HPV infections and cancers caused by the oncoviruses Epstein-Barr Virus, HHV-8 and HPV. This workshop examined four questions regarding the viruses associated with oral cancers and disease in the HIV-positive and -negative populations, the immune response, and biomarkers useful for accurate diagnostics of these infections and their sequalae. Each presenter identified a number of key areas where further research is required.

Detecting DNA viruses in oral fluids: evaluation of collection and storage methods

Storing saliva for nucleic acid diagnostics is problematic in resource-constrained settings. DNA Genotek's OMNIgene™·DISCOVER kit aims to stabilise microbial DNA at room temperature. We evaluate this for long-term storage, determining DNA quantity/purity and human herpesvirus 8 (HHV-8) load as indicator. Viral loads and DNA degradation were assayed over 14months in HHV-8-negative saliva spiked with cell-associated and cell-free virus and saliva collected fresh frozen and into kits from 10 HIV-positive patients. Viral loads remained constant for 6-9months, yielding high quantities of DNA: subsequent losses were ≤48%. Patient samples, frozen or kit stored, produced pure DNA of comparable concentration. Higher HHV-8 detection in frozen saliva resulted from losses during ethanol precipitation using kits. After 14months, DNA degradation was significant in frozen saliva, but that in kits had integrity similar to fresh samples. Storing frozen saliva is detrimental. This kit is well suited for collection, long-term storage, and assay of viral DNA in resource-constrained settings.

Comparison of salivary collection and processing methods for quantitative HHV-8 detection

OBJECTIVES

Saliva is a proved diagnostic fluid for the qualitative detection of infectious agents, but the accuracy of viral load determinations is unknown. Stabilising fluids impede nucleic acid degradation, compared with collection onto ice and then freezing, and we have shown that the DNA Genotek P-021 prototype kit (P-021) can produce high-quality DNA after 14 months of storage at room temperature. Here we evaluate the quantitative capability of 10 collection/processing methods.

METHODS

Unstimulated whole mouth fluid was spiked with a mixture of HHV-8 cloned constructs, 10-fold serial dilutions were produced, and samples were extracted and then examined with quantitative PCR (qPCR). Calibration curves were compared by linear regression and qPCR dynamics.

RESULTS

All methods extracted with commercial spin columns produced linear calibration curves with large dynamic range and gave accurate viral loads. Ethanol precipitation of the P-021 does not produce a linear standard curve, and virus is lost in the cell pellet. DNA extractions from the P-021 using commercial spin columns produced linear standard curves with wide dynamic range and excellent limit of detection.

CONCLUSION

When extracted with spin columns, the P-021 enables accurate viral loads down to 23 copies μl(-1) DNA. The quantitative and long-term storage capability of this system makes it ideal for study of salivary DNA viruses in resource-poor settings.

Early childhood infection of Kaposi's sarcoma-associated herpesvirus in Zambian households: a molecular analysis

Sub-Saharan Africa is endemic for Kaposi's sarcoma-associated herpesvirus (KSHV) and there is a high rate of early childhood infection; however, the transmission sources are not well characterized. We examined household members as potential KSHV transmission sources to young children in the KSHV-endemic country of Zambia. To this end, we enrolled and followed Zambian households with at least one KSHV-seropositive child and collected longitudinal buccal swab samples. KSHV burden was evaluated and K1 sequences from the children were determined and analyzed for differences to K1 sequences from household members. The K1 sequences were also analyzed for evolution over time. We generated K1 sequences from 31 individuals across 16 households. Nine households contained multiple KSHV-positive members, including at least one child. In six out of the nine households, the child had 100% sequence identity to all household members. However, in two households the child and mother had distinct K1 sequences. In the remaining household, the children were the only KSHV-infected individuals. Furthermore, we report that 1 out of 18 individuals had K1 sequence variation within the timespan analyzed. In our study, we provide evidence that (i) early childhood KSHV transmission occurs from both within and outside the household, (ii) intrahousehold transmission can occur via nonmaternal sources, (iii) viral shedding in the buccal cavity is highly variable and (iv) the dominant K1 sequence within an individual did not rapidly evolve over time. These results are important for developing KSHV intervention strategies.

PCR detection of multiple human herpesvirus DNA in saliva from HIV-infected individuals in Teresina, State of Piauí, Brazil

INTRODUCTION: Human herpesviruses are frequently associated with orofacial diseases in humans (HSV-1, EBV, CMV and HHV-8), some can also cause systemic disease (CMV and HHV-8). The transmission of these viruses occurs by contact with infected secretions, especially saliva. Human immunodeficiency virus infection is associated with an increased risk of HHVs and related diseases. METHODS: This work aimed to detect HSV-1, EBV, CMV and HHV-8 DNA in saliva of HIV-infected patients from Teresina, northeast Brazil, by PCR and compare these findings with age and sex matched HIV-seronegative individuals. RESULTS: No difference in prevalence was verified between HHV detection in the saliva of HIV-seropositive individuals and controls. The individual frequencies of these viruses in these two populations were different. HIV seropositivity correlated positively with the presence of CMV (OR: 18.2, p= 0.00032) and EBV (OR: 3.44, p= 0.0081). No association between CD4 counts and the prevalence of HHVs in the saliva was observed; however, a strong association was determined between seropositivity and the presence of multiple HHV DNAs in saliva (OR: 4.83, p = 0.0028). CONCLUSIONS: These findings suggest the asymptomatic salivary shedding of HHVs is a common event between HIV-seropositive and seronegative individuals from Teresina, Piauí, Brazil, and, especially for HIV-seropositive patients, saliva is a risk factor for the acquisition/transmission of multiple HHVs.

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.

Periodontitis lesions are the main source of salivary cytomegalovirus

BACKGROUND

Herpesviruses play causal or cooperative roles in childhood infections, tumorigenesis, ulcerogenesis, and periodontitis. Saliva is a common vehicle of herpesvirus horizontal transmission, but the source of salivary herpesviruses remains obscure. To evaluate the significance of periodontal disease in shedding of oral herpesviruses, this study determined the genome-copy counts of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in whole saliva of subjects with periodontitis, gingivitis, or no natural teeth.

METHODS

Whole saliva was collected from 14 periodontitis patients, 15 gingivitis patients and 13 complete denture wearers. The study subjects were systemically healthy and had not received periodontal treatment in the past 3 months. Real-time TaqMan polymerase chain reaction was used to determine the salivary load of HCMV and EBV.

RESULTS

Salivary HCMV was detected in seven (50%) periodontitis patients, but not in any gingivitis or edentulous subjects (P < 0.001). Salivary EBV was detected in 11 (79%) periodontitis patients, in five (33%) gingivitis patients, and in seven (54%) edentulous subjects (P = 0.076). Salivary samples showed copy counts of HCMV in the range of 3.3 x 10(3)-4.2 x 10(4)/ml and of EBV in the range of 3.6 x 10(2)-1.6 x 10(9)/ml.

CONCLUSIONS

HCMV and EBV are commonly present in the saliva of periodontitis patients. Periodontitis lesions of systemically healthy subjects seem to constitute the main origin of salivary HCMV, but do not comprise the sole source of salivary EBV.