Serological evidence of vertical transmission of JC and BK polyomaviruses in humans

The molecular footprints of BK virus in the product of conception over the second and third gestational trimesters

OBJECTIVE

Prior studies have shown controversial results on the vertical transmission of BK virus (BKV). The present study aimed to assess the possibility of BKV vertical transmission from mother to fetus in the product of conception (embryo, fetuses, and/or placentas) over the three stages of pregnancy.

RESULTS

Of the 26 placental studied tissues, 6 were in the first trimester, and none of which were positive. Only one out of the 13 (7.7%) placental materials in the second trimester was positive. Only one out of 7 (14%) placental materials of the third trimester was positive. There were cases that no virus was detected in their placental but BKV was detected in their other tissues. Among 26 conceptuses, 17 (65%) were negative for BKV and 9 (34.6%) were positive, 7/13 (54%) were positive in the second, and 2/7 (29%) were positive in the third trimester fetuses. BKV was most frequently detected in the liver (eight cases), heart (three cases), and placenta (2 cases). There were cases that no virus was detected in their placental but BKV was detected in their other tissues.

IgG Seroreactivites to Viral Capsid Protein VP1 of JC and BK Polyomaviruses in Children at Early Ages with Special Reference to Parental Cofactors

BK (BKPyV) and JC (JCPyV) polyomaviruses are widespread in humans. Transmission at an early age and the role of parents in spreading these viruses through the family are incompletely understood. Our aim was to determine the seroprevalence of BKPyV and JCPyV in infants at the age of 1, 2, 6, 12, 24, and 36 months and to assess the frequency of BKPyV and JCPyV seroconversion. A variety of maternal and paternal covariates were also tested as potential predictors of these early childhood infections. We used multiplex serology to analyze antibodies to BKPyV and JCPyV from baseline to 3-year follow-up visits. We observed that there was nearly perfect correlation in BKPyV and JCPyV serum IgG antibody levels between the mother-infant pairs during the first year of the infant's life. No correlation among BKPyV antibody titers were found in father-child pairs, whereas JCPyV antibody levels of the father and child had a significant correlation at the 2-year follow-up visit. BKPyV infection may be associated with a child's predisposition to allergy. In conclusion, after the decay of maternal antibodies, children start to develop their own immunity toward BKPyV and JCPyV, and horizontal transmission of infection in the family can occur.

Gestational Viral Infections: Role of Host Immune System

Viral infections in pregnancy are major causes of maternal and fetal morbidity and mortality. Infections can develop in the neonate transplacentally, perinatally, or postnatally (from breast milk or other sources) and lead to different clinical manifestations, depending on the viral agent and the gestational age at exposure. Viewing the peculiar tolerogenic status which characterizes pregnancy, viruses could exploit this peculiar immunological status to spread or affect the maternal immune system, adopting several evasion strategies. In fact, both DNA and RNA virus might have a deep impact on both innate and acquired immune systems. For this reason, investigating the interaction with these pathogens and the host's immune system during pregnancy is crucial not only for the development of most effective therapies and diagnosis but mostly for prevention. In this review, we will analyze some of the most important DNA and RNA viruses related to gestational infections.

Evolutionary analysis of JC polyomavirus in Misiones' population yields insight into the population dynamics of the early human dispersal in the Americas

BACKGROUND

JC polyomavirus (JCV) has an ethno-geographical distribution across human populations.

OBJECTIVE

Study the origins of the population of Misiones (Argentina) by using JCV as genetic marker.

METHODS

Viral detection and characterization was conducted by PCR amplification and evolutionary analysis of the intergenic region sequences.

RESULTS

22 out of 121 samples were positive for JCV, including 5 viral lineages: MY (n = 8), Eu-a (n = 7), B1-c (n = 4), B1-b (n = 2) and Af2 (n = 1). MY sequences clustered within a branch of Native American origin that diverged from its Asian counterpart about 21,914 years ago (HPD 95% interval 15,383-30,177), followed by a sustained demographic expansion around 5000 years ago.

CONCLUSIONS

JCV in Misiones reflects the multiethnic origin of the current population, with an important Amerindian contribution. Analysis of the MY viral lineage shows a pattern consistent with the arrival of early human migrations to the Americas and a population expansion by the pre-Columbian native societies.

The effect of BK polyomavirus large T antigen on CD4 and CD8 T cells in kidney transplant recipients

Human BK polyomavirus (BKPyV) can affect the machinery of the host cell to induce optimal viral replication or transform them into tumor cells. Reactivation of BKPyV happens due to immunosuppression therapies following renal transplantation which might result in BK polyomavirus nephropathy (BKPyVAN) and allograft loss. The first protein that expresses after entering into host cells and has an important role in pathogenicity is the Large T antigen (LT-Ag). In this review tries to study the molecular and cellular inter-regulatory counteractions especially between CD4 and CD8 T cells, and BKPyV LT-Ag may have role in nephropathy after renal transplantation.

Clinically relevant DNA viruses in pregnancy

Infections by DNA viruses during pregnancy are associated with increased health risks to both mother and fetus. Although not all DNA viruses are related to an increased risk of complications during pregnancy, several can directly infect the fetus and/or cause placental dysfunction. During NIPT analysis, the presence of viral DNA can be detected, theoretically allowing screening early in pregnancy. Although treatment options are currently limited, this might rapidly change in the near future. It is therefore important to be aware of the potential impact of these viruses on feto-maternal health. In this manuscript we provide a brief introduction into the most commonly detected DNA viruses in human cell-free DNA sequencing experiments and their pathogenic potential during pregnancy. This article is protected by copyright. All rights reserved.

CC and CXC chemokines play key roles in the development of polyomaviruses related pathological conditions

It has been reported that polyomaviruses are the microbes which can be a cause of several human pathological conditions including cancers, nephropathy, progressive multifocal leukoencephalopathy and gynaecological disease. Although investigators proposed some mechanisms used by the viruses to induce the disorders, the roles played by chemokines in the pathogenesis of polyomaviruses infections are yet to be clarified. This review article investigated recent studies regarding the roles played by chemokines in the pathogenesis of the polyomaviruses infections. The research in the literature revealed that CXC chemokines, including CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL12 and CXCL16, significantly participate in the pathogenesis of polyomaviruses. CC chemokines, such as CCL2, CCL5 and CCL20 also participate in the induction of the pathological conditions. Therefore, it appears that CXC chemokines may be considered as the strategic factors involved in the pathogenesis of polyomaviruses.

JC Polyomavirus Infection Potentiated by Biologics

The risk of JC polyomavirus encephalopathy varies among biologic classes and among agents within the same class. Of currently used biologics, the highest risk is seen with natalizumab followed by rituximab. Multiple other agents have also been implicated. Drug-specific causality is difficult to establish because many patients receive multiple immunomodulatory medications concomitantly or sequentially, and have other immunocompromising factors related to their underlying disease. As use of biologic therapies continues to expand, further research is needed into pathogenesis, treatment, and prevention of JC polyomavirus encephalopathy such that risk for its development is better understood and mitigated, if not eliminated altogether.

You Will Never Walk Alone: Codispersal of JC Polyomavirus with Human Populations

JC polyomavirus (JCPyV) is one of the most prevalent human viruses. Findings based on the geographic distribution of viral subtypes suggested that JCPyV codiverged with human populations. This view was however challenged by data reporting a much more recent origin and expansion of JCPyV. We collected information on ∼1,100 worldwide strains and we show that their geographic distribution roughly corresponds to major human migratory routes. Bayesian phylogeographic analysis inferred a Subsaharan origin for JCPyV, although with low posterior probability. High confidence inference at internal nodes provided strong support for a long-standing association between the virus and human populations. In line with these data, pairwise FST values for JCPyV and human mtDNA sampled from the same areas showed a positive and significant correlation. Likewise, very strong relationships were found when node ages in the JCPyV phylogeny were correlated with human population genetic distances (nuclear-marker based FST). Reconciliation analysis detected a significant cophylogenetic signal for the human population and JCPyV trees. Notably, JCPyV also traced some relatively recent migration events such as the expansion of people from the Philippines/Taiwan area into Remote Oceania, the gene flow between North-Eastern Siberian and Ainus, and the Koryak contribution to Circum-Arctic Americans. Finally, different molecular dating approaches dated the origin of JCPyV in a time frame that precedes human out-of-Africa migration. Thus, JCPyV infected early human populations and accompanied our species during worldwide dispersal. JCPyV typing can provide reliable geographic information and the virus most likely adapted to the genetic background of human populations.

Footprints of BK and JC polyomaviruses in specimens from females affected by spontaneous abortion

STUDY QUESTION

Are JC polyomavirus (JCPyV) and BK polyomavirus (BKPyV) infections associated with spontaneous abortion (SA)?

SUMMARY ANSWER

There is no association of JCPyV or BKPyV with SA.

WHAT IS KNOWN ALREADY

A large number of risk factors have been associated with SA. The role of polyomaviruses, including JCPyV and BKPyV, in SA remains to be clarified.

STUDY DESIGN, SIZE, DURATION

This is a case-control study including women affected by spontaneous abortion (SA, n = 100, the cases) and women who underwent voluntary interruption of pregnancy (VI, n = 100, the controls).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Viral DNAs were investigated by qualitative PCR and quantitative droplet-digital PCR (ddPCR) in matched chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) from SA (n = 100) and VI (n = 100). Indirect ELISAs with mimotopes/synthetic peptides corresponding to JCPyV and BKPyV viral capsid protein 1 epitopes were then employed to investigate specific IgG antibodies against JCPyV and BKPyV in human sera from SA (n = 80) and VI (n = 80) cohorts.

MAIN RESULTS AND THE ROLE OF CHANCE

JCPyV DNA was detected in 51% and 61% of SA and VI samples, respectively, with a mean viral DNA load of 7.92 copy/104 cells in SA and 5.91 copy/104 cells in VI (P > 0.05); BKPyV DNA was detected in 11% and 12% of SA and VI specimens, respectively, with a mean viral DNA load of 2.7 copy/104 cells in SA and 3.08 copy/104 cells in VI (P > 0.05). JCPyV was more prevalent than BKPyV in both SA and VI specimens (P < 0.0001). In PBMCs from the SA and VI cohorts, JCPyV DNA was detected with a prevalence of 8% and 12%, respectively, with a mean viral DNA load of 2.29 copy/104 cells in SA and 1.88 copy/104 cells in VI (P > 0.05). The overall prevalence of serum IgG antibodies against JCPyV detected by indirect ELISAs was 52.5% and 48.7% in SA and VI groups, respectively, whereas BKPyV-positive sera were found in 80% SA and 78.7% VI samples.

LIMITATIONS, REASONS FOR CAUTION

This study did not investigate the presence of viral mRNA and/or proteins, which are indicative of an active viral infection, and these might be taken into consideration in future studies.

WIDER IMPLICATIONS OF THE FINDINGS

JCPyV and BKPyV DNA sequences were detected and quantitatively analyzed for the first time by PCR/ddPCR in chorionic villi tissues and PBMCs from SA and VI specimens. Moreover specific immunological approaches detected serum IgG against JCPyV/BKPyV. Statistical analyses, however, do not indicate an association between these polyomaviruses and SA.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the University of Ferrara, FAR research grants and the University Hospital of Ferrara/University of Ferrara joint grant. No potential conflicts of interest were disclosed.

Mother-to-child transmission of oncogenic polyomaviruses BKPyV, JCPyV and SV40

OBJECTIVES

Polyomavirus (PyV) infections have been associated with different diseases. BK (BKPyV), JC (JCPyV) and simian virus 40 (SV40) are the three main PyVs whose primary infection occurs early in life. Their vertical transmission was investigated in this study.

METHODS

PyV sequences were analyzed by the digital droplet PCR in blood, serum, placenta, amniotic fluid, vaginal smear from two independent cohorts of pregnant females and umbilical cord blood (UCB) samples. IgG antibodies against the three PyVs were investigated by indirect E.L.I.S.As with viral mimotopes.

RESULTS

DNAs from blood, vaginal smear and placenta tested BKPyV-, JCPyV- and SV40-positive with a distinct prevalence, while amniotic fluids were all PyVs-negative. A prevalence of 3%, 7%, and 3% for BKPyV, JCPyV and SV40 DNA sequences, respectively, was obtained in UCBs. Serum IgG antibodies from pregnant females reached an overall prevalence of 62%, 42% and 17% for BKPyV, JCPyV and SV40, respectively. Sera from newborns (UCB) tested IgG-positive with a prevalence of 10% for BKPyV/JCPyV and 3% for SV40.

CONCLUSIONS

In this investigation, PyV vertical transmission was revealed by detecting PyV DNA sequences and IgG antibodies in samples from females and their offspring suggesting a potential risk of diseases in newborns.

Genetic diversity of the JC polyomavirus (JCPyV) and mitochondrial DNA ancestry in Misiones, Argentina

BACKGROUND

The use of human and viral genetic markers offers a novel way to study human migration in multiethnic populations of Latin America.

OBJECTIVES

Our goal was to characterize the genetic diversity and geographical origins of JC Polyomavirus (JCPyV) and the genetic ancestry of mitochondrial DNA (mtDNA) in inhabitants from 25 de Mayo, Misiones-Argentina, a small village of largely German ancestry located close to the border with Brazil. We also evaluated the extent of agreement between viral and mtDNA markers for the different ancestry components of this population.

STUDY DESIGN

68 individuals were analyzed for JCPyV and mtDNA diversity. JCPyV detection and typing was conducted in urine samples by PCR amplification, sequencing and phylogenetic analysis of the VP1 gene. mtDNA ancestry was assessed through HVS1 sequencing, with the resulting haplotypes being classified into haplogroups of Amerindian, European and African origin. The distribution of JCPyV diversity and mtDNA ancestry in the population was statistically evaluated by Fisher exact test and the level of agreement of both markers at the individual level was evaluated by Cohen's kappa coefficient.

RESULTS

Our analysis showed that 57.4% of the samples were positive for JCPyV. Of these, the 47.6% were Asian-American Type 2, 33.3% European Type 1 and 19.1% African Type 3 in origin. The mtDNA ancestry of the study participants was 33.3% Amerindian and 66.7% European. There was a significant difference among the distribution of JCPyV diversity and mtDNA ancestry (p = 0.009) and at the individual level there was no correlation between the distribution of the both markers (κ = 0.154, p = 0.297).

CONCLUSION

The apparent incongruence between JCPyV diversity and mtDNA ancestry may reflect the original settlement process and more recent migration to 25 de Mayo, the latter involving viral spread through migrants from Brazil. Some potential limitations to our interpretations are also discussed.

T cell deficiencies as a common risk factor for drug associated progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a disease of the central nervous system caused by neuropathogenic prototypes of ubiquitous community-acquired JC virus (JCV). The disease became of particular concern following its association with certain therapies that modulate immune system function without heavy immunosuppression. Due to lack of prophylactic/treatment options and poor outcomes, which often include severe disability or death, PML is a considerable concern for development of new drugs that interfere with immune system functions. In this review of clinical and research findings, we discuss the evidence that deficiencies in CD4⁺ T helper cells, cytotoxic CD8⁺ T cells, and interferon gamma are of crucial importance for development of PML under a variety of circumstances, including those associated with use of various drugs, regardless of differences in their mechanisms of action. These deficiencies apparently enable transformation of the harmless JCV archetype into neuropathogenic prototypes, but the site(s), and the mechanisms, of this transformation are yet to be elucidated. Here we discuss the evidence for brain as one of the sites of this transformation, and propose a model of PML pathogenesis that emphasizes the central role of T cell deficiencies in the two life cycles of the JCV, one non-pathogenic and one neuropathogenic. Finally, we conclude that the development of clinical grade T cell functional tests and more consistent use of already available laboratory tests for T cell subset analysis would greatly aid the effort to more accurately predict and assess the magnitude of PML risk for concerned therapeutic interventions.

A Naturally Transmitted Epitheliotropic Polyomavirus Pathogenic in Immunodeficient Rats: Characterization, Transmission, and Preliminary Epidemiologic Studies

We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Unbiased viral metagenomic sequencing of lesioned tissues identified a novel polyomavirus, provisionally named Rattus norvegicus polyomavirus 2 (RatPyV2), which clustered with Washington University (WU) polyomavirus in the Wuki clade of the Betapolyomavirus genus. In situ hybridization analyses and quantitative polymerase chain reaction (PCR) results demonstrated viral nucleic acids in epithelium of respiratory, glandular, and reproductive tissues. Polyomaviral disease was reproduced in Foxn1^rnu nude rats cohoused with infected rats or experimentally inoculated with virus. After development of RatPyV2-specific diagnostic assays, a survey of immune-competent rats from North American research institutions revealed detection of RatPyV2 in 7 of 1,000 fecal samples by PCR and anti-RatPyV2 antibodies in 480 of 1,500 serum samples. These findings suggest widespread infection in laboratory rat populations, which may have profound implications for established models of respiratory injury. Additionally, RatPyV2 infection studies may provide an important system to investigate the pathogenesis of WU polyomavirus diseases of man.

Specific IgG Antibodies React to Mimotopes of BK Polyomavirus, a Small DNA Tumor Virus, in Healthy Adult Sera

BK polyomavirus (BKPyV) was isolated in 1971 from the urine of a kidney transplant patient. Soon after its identification, BKPyV was characterized as a kidney-tropic virus, which is responsible of a significant fraction of the rejection of transplant kidney in the host. Moreover, in experimental conditions, BKPyV is able to transform different types of animal and human cells and to induce tumors of different histotypes in experimental animals. BKPyV DNA sequences have been detected in healthy individuals and cancer patients using polymerase chain reaction/Shouthern blot hybridization methods. Serum antibodies against this polyomavirus were revealed using immunological techniques, which, however, cross-react with other polyomaviruses such as JC (JCPyV) and Simian Virus 40. These non-specific data indicate the need of novel immunological methods and new investigations to check in a specific manner, BKPyV spread in humans. To this aim, mimotopes from BKPyV structural capsid protein 1 (VP1) were employed for specific immunological reactions to IgG antibodies of human serum samples. An indirect enzyme-linked immunosorbent assay with synthetic peptides mimicking immunogenic epitopes of BKPyV VP1 was set up and employed to test sera of healthy adult subjects. Data from this innovative immunological assay indicate that serum antibodies against BKPyV VP1 mimotopes are detectable in healthy subjects ranging from 18 to 90 years old. The overall prevalence of serum samples that reacted to BKPyV VP1 mimotopes was 72%. The strong points from this investigation are the novelty of the immunological method, its simplicity of the approach, and the specificity of BKPyV antibody reaction to VP1 mimotopes.

Tumor growth factor-β is an important factor for immunosuppression and tumorgenesis in Polyoma BK virus infection; a systematic review article

Polyoma BK virus (PBK) is a prevalent human specific virus and the cause of several malignancies in human. The main mechanisms used by PBK to induce/stimulate human cancers are yet to be clarified but it has been proposed that PBK may use several mechanisms to induce/stimulate cancers in human including attenuation of immune responses via up-regulation of immunosuppressor molecules. Transforming growth factor beta (TGF-β) is a key multifunctional factor from modulation of immunosurveillance to angiogenesis. The key roles of TGF-β in the progression of Th17 and T regulatory subsets, the most important immune cells involved in development of cancers, have been demonstrated. Thus, this review article aims to describe the mechanisms used by PBK in induction/stimulation of human cancers in TGF-β dependent manner..

IL-2 and polyoma BK virus infection; A systematic review article

It has been demonstrated that IL-2 plays a dual role in induction/suppression of immune responses via activation of conventional and regulatory T lymphocytes, respectively. IL-2 contacts complete IL-2 receptor (IL-2R) which contains CD25 (α chain) on the antigen specific activated T helper and cytotoxic lymphocytes and also T regulatory cells. Additionally, previous investigations revealed that polyoma BK virus (PBK) reactivation and induction of PBK associated nephropathy (PBKAN) is a main complication following renal transplantation. Based on the important dual roles played by IL-2 in the immune responses, it may be hypothesized that IL-2/IL-2R interaction could be considered a potential mechanism against/toward PBK reactivation and also PBKAN. Accordingly, the aim of the current review article is to determine the roles of IL-2 IL-2/IL-2R interaction in PBK reactivation and PBKAN complications.

JC virus infection is acquired very early in life: evidence from a longitudinal serological study

JC virus (JCV) is a widespread member of the Polyomaviridae family. Following primary infection, which occurs asymptomatically during childhood, JCV establishes latency in the host. JCV seroprevalence can reach 80 % in healthy adults, but the age of viral exposure has not been yet characterized. This study was conducted to define JCV seroprevalence in Italian infants and to estimate the date of primary infection. A JCV viral protein 1 (VP1)-GST fusion protein was used in conjunction with a homemade indirect enzyme-linked immunosorbent assay (ELISA) to test for the presence of IgG antibodies to JCV in 981 serum samples collected from 644 Italian infants of different ages (1 day to 3 years old) and in 102 breast milk samples. IgM antibody presence was also evaluated in longitudinally collected samples from 17 selected children. JCV antibody prevalence and normalized optical density (nOD) were calculated. For the longitudinal analysis, generalized estimating equation techniques and spline functions were used to estimate the possible non-linear effects of time on antibody production kinetics. JCV IgG was detected in 71.8 % of the sera. Prevalence increased over time from 46.1 % (1 month old) to 80.7 % (12 months old), 85.9 % (24 months old), and 85.5 % (36 months old). As determined by nOD, the longitudinal analysis of serum IgG amounts in children of this study (ages 1 day to 3 years old) illustrated IgG kinetic changes with statistically significant trends (p = 0.001). One-month-old children were largely negative for JCV IgM (82.4 %), and 58.8 % of children produced JCV IgM within the second and sixth months of life. JCV IgG was detected in 27.3 % of breast milk samples. JCV primary infection likely occurs before 6 months of age, and a sizeable percentage of Italian infants will become JCV seropositive within 2 years of age. This study can be used to determine the optimal age for potential future JCV vaccination in infants.

BK Virus Nephropathy in Kidney Transplantation: An Approach Proposal and Update on Risk Factors, Diagnosis, and Treatment

BK virus belongs to Polyomaviridae family; it causes 95% of nephropathy cases related to polyomavirus, with the other 5% caused by JC virus. Nephropathy jeopardizes graft function, causing a premature failure of the graft in 1%-10% of patients with kidney transplants. Nowadays, antiviral effective treatment is unknown, which is why blood and urine screening of renal transplantation patients has become the most important recommendation to guide the decrease of immunosuppression, and the only proven method to decrease poor outcomes. Different interventions, such as cidofovir, leflunomide, fluoroquinolones, and intravenous immunoglobulin, have been attempted with no improvement at all. This review aims to summarize the most relevant features of BK virus, historical issues, transmission mechanisms, risk factors, and therapeutic interventions.

Innate Immunity and BK Virus: Prospective Strategies

Recent information demonstrated that BK virus reactivation is a dominant complication after kidney transplantation, which occurs because of immunosuppression. BK virus reactivation is the main reason of transplanted kidney losing. Immune response against BK virus is the major inhibitor of the virus reactivation. Therefore, improving our knowledge regarding the main parameters that fight against BK viruses can shed light on to direct new treatment strategies to suppress BK infection. Innate immunity consists of numerous cell systems and also soluble molecules, which not only suppress virus replication, but also activate adaptive immunity to eradicate the infection. Additionally, it appears that immune responses against reactivated BK virus are the main reasons for induction of BK virus-associated nephropathy (BKAN). Thus, improving our knowledge regarding the parameters and detailed mechanisms of innate immunity and also the status of innate immunity of the patients with BK virus reactivation and its complications can introduce new prospective strategies to either prevent or as therapy of the complication. Therefore, this review was aimed to collate the most recent data regarding the roles played by innate immunity against BK virus and also the status of innate immunity in the patients with reactivation BK virus and BKAN.

Detection of Japanese eel endothelial cells-infecting virus in Anguilla japonica elvers

Japanese eel endothelial cells-infecting virus (JEECV) has spread in eel farms and caused serious economic loss. In this study, we examined the prevalence of JEECV infection in 100 wild Japanese eel (Anguilla japonica) elvers caught from Yamaguchi prefecture, Japan, using quantitative PCR and conventional PCR. Total genomic DNA was obtained from the cranial quarter of the body in 70 of 100 eels and from the gill in the remaining. Of 30 gill samples, 20 were analyzed after pooling with other samples, and the remaining 10 were analyzed separately. A single positive result for JEECV was detected following analysis of the 10 separately analyzed samples. This result constitutes the first report of JEECV infection in wild A. japonica elvers.

Human BK Polyomavirus-The Potential for Head and Neck Malignancy and Disease

Members of the human Polyomaviridae family are ubiquitous and pathogenic among immune-compromised individuals. While only Merkel cell polyomavirus (MCPyV) has conclusively been linked to human cancer, all members of the polyomavirus (PyV) family encode the oncoprotein T antigen and may be potentially carcinogenic. Studies focusing on PyV pathogenesis in humans have become more abundant as the number of PyV family members and the list of associated diseases has expanded. BK polyomavirus (BKPyV) in particular has emerged as a new opportunistic pathogen among HIV positive individuals, carrying harmful implications. Increasing evidence links BKPyV to HIV-associated salivary gland disease (HIVSGD). HIVSGD is associated with elevated risk of lymphoma formation and its prevalence has increased among HIV/AIDS patients. Determining the relationship between BKPyV, disease and tumorigenesis among immunosuppressed individuals is necessary and will allow for expanding effective anti-viral treatment and prevention options in the future.

Neutralizing and IgG antibodies against simian virus 40 in healthy pregnant women in Italy

OBJECTIVE

Polyomavirus simian virus 40 (SV40) sequences have been detected in various human specimens and SV40 antibodies have been found in human sera from both healthy individuals and cancer patients. This study analyzed serum samples from healthy pregnant women as well as cord blood samples to determine the prevalence of SV40 antibodies in pregnancy.

METHODS

Serum samples were collected at the time of delivery from two groups of pregnant women as well as cord bloods from one group. The women were born between 1967 and 1993. Samples were assayed by two different serological methods, one group by neutralization of viral infectivity and the other by indirect ELISA employing specific SV40 mimotopes as antigens. Viral DNA assays by real-time polymerase chain reaction were carried out on blood samples.

RESULTS

Neutralization and ELISA tests indicated that the pregnant women were SV40 antibody-positive with overall prevalences of 10.6% (13/123) and 12.7% (14/110), respectively. SV40 neutralizing antibodies were detected in a low number of cord blood samples. Antibody titers were generally low. No viral DNA was detected in either maternal or cord bloods.

CONCLUSIONS

SV40-specific serum antibodies were detected in pregnant women at the time of delivery and in cord bloods. There was no evidence of transplacental transmission of SV40. These data indicate that SV40 is circulating at a low prevalence in the northern Italian population long after the use of contaminated vaccines.

Oncogenic Papillomavirus and Polyomavirus in Water Environments: Is There a Potential for Waterborne Transmission?

Waterborne exposure to human viruses through contact with sewage-contaminated water environments can result in infections associated with a wide range of illnesses. Gastrointestinal symptoms are the most commonly encountered manifestations of waterborne viral illness. Respiratory diseases, neurological diseases and paralysis can also occur. Whether viral infections resulting in health outcomes like cancer might also be transmitted by the waterborne route is unknown. Recently, viruses belonging to two oncogenic groups-Human Papillomaviruses (HPVs) and Human Polyomaviruses (HPyVs)-have been detected in urban sewages worldwide. The latter have also been identified in other water environments. HPVs are epitheliotropic viruses responsible for several diseases of skin and mucosae, from common warts to squamous intraepithelial lesions that can either heal or progress to invasive carcinoma of the cervix, vulva, vagina, penis, anus or oropharynx. Human PyVs infect different tissues and organs, causing infections that are usually subclinical in immunocompetent individuals but can be serious in immunocompromised hosts. These pathogens belong to a family of DNA tumour viruses. Merkel cell polyomavirus, a HPyV identified in recent years, has attracted much attention due to its link with a rare and aggressive form of human cancer. Merkel cell carcinoma, the incidence of which has tripled over the past two decades. JC polyomavirus and BK polyomavirus are also potentially oncogenic. The observed abundance and wide dissemination of HPVs and HPyVs in water environments strongly suggest the need to shed light on the fate of these viruses in water environments and to elucidate their potential for waterborne transmission. Such information is essential for the improvement of wastewater management programs in terms of both sewage treatment and water quality surveillance.

Different serologic behavior of MCPyV, TSPyV, HPyV6, HPyV7 and HPyV9 polyomaviruses found on the skin

The polyomavirus family is rapidly expanding with twelve new human viruses identified since 2007. A significant number of the new human polyomaviruses (HPyV) has been found on the skin. Whether these viruses share biological properties and should be grouped together is unknown. Here we investigated the serological behavior of cutaneous HPyVs in a general population. 799 sera from immunocompetent Australian individuals aged between 0-87 were analyzed with a Luminex xMAP technology-based immunoassay for the presence of VP1-directed IgG antibodies against MCPyV, HPyV6, HPyV7, TSPyV, HPyV9, and BKPyV as a control. Except for HPyV9, overall seropositivity was high for the cutanous polyomaviruses (66-81% in adults), and gradually increased with age. Children below 6 months displayed seropositivity rates comparable to the adults, indicative of maternal antibodies. TSPyV seroreactivity levels strongly increased after age 2 and waned later in life comparable to BKPyV, whereas MCPyV, HPyV6 and HPyV7 seroreactivity remained rather stable throughout. Based on the identified serologic profiles, MCPyV seems to cluster with HPyV6 and HPyV7, and TSPyV and HPyV9 by themselves. These profiles indicate heterogeneity among cutaneous polyomaviruses and probably reflect differences in exposure and pathogenic behavior of these viruses.

The human JC polyomavirus (JCPyV): virological background and clinical implications

JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35-70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50,000 copies/mL urine. PML is rare having an incidence of <0.3 per 100,000 person years in the general population. This increased to 2.4 per 1000 person years in HIV-AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4-integrin-dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV-specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo-)encephalitis, and non-replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.

Human polyomavirus reactivation: disease pathogenesis and treatment approaches

JC and BK polyomaviruses were discovered over 40 years ago and have become increasingly prevalent causes of morbidity and mortality in a variety of distinct, immunocompromised patient cohorts. The recent discoveries of eight new members of the Polyomaviridae family that are capable of infecting humans suggest that there are more to be discovered and raise the possibility that they may play a more significant role in human disease than previously understood. In spite of this, there remains a dearth of specific therapeutic options for human polyomavirus infections and an incomplete understanding of the relationship between the virus and the host immune system. This review summarises the human polyomaviruses with particular emphasis on pathogenesis in those directly implicated in disease aetiology and the therapeutic options available for treatment in the immunocompromised host.

Molecular biology, epidemiology, and pathogenesis of progressive multifocal leukoencephalopathy, the JC virus-induced demyelinating disease of the human brain

Progressive multifocal leukoencephalopathy (PML) is a debilitating and frequently fatal central nervous system (CNS) demyelinating disease caused by JC virus (JCV), for which there is currently no effective treatment. Lytic infection of oligodendrocytes in the brain leads to their eventual destruction and progressive demyelination, resulting in multiple foci of lesions in the white matter of the brain. Before the mid-1980s, PML was a relatively rare disease, reported to occur primarily in those with underlying neoplastic conditions affecting immune function and, more rarely, in allograft recipients receiving immunosuppressive drugs. However, with the onset of the AIDS pandemic, the incidence of PML has increased dramatically. Approximately 3 to 5% of HIV-infected individuals will develop PML, which is classified as an AIDS-defining illness. In addition, the recent advent of humanized monoclonal antibody therapy for the treatment of autoimmune inflammatory diseases such as multiple sclerosis (MS) and Crohn's disease has also led to an increased risk of PML as a side effect of immunotherapy. Thus, the study of JCV and the elucidation of the underlying causes of PML are important and active areas of research that may lead to new insights into immune function and host antiviral defense, as well as to potential new therapies.

Progressive multifocal leukoencephalopathy: why gray and white matter

Since it was first described in 1958, progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the brain caused by the polyomavirus JC (JCV), has evolved tremendously. It was once considered a noninflammatory disease that affected exclusively oligodendrocytes and astrocytes in the white matter of immunosuppressed individuals and was almost always fatal. Today, we understand that PML can present during the course of an immune reconstitution inflammatory syndrome and that it affects a broader range of individuals, including patients with minimal immunosuppression and those who are treated with novel immunomodulatory medications. Furthermore, JCV-infected glial cells are frequently located at the gray matter-white matter junction or within the gray matter, causing demyelinating lesions within cortical areas. Finally, JCV variants can also infect neurons, leading to the recognition of two distinct clinical entities: JCV granule cell neuronopathy and JCV encephalopathy.

Novel human polyomaviruses in pregnancy: higher prevalence of BKPyV, but no WUPyV, KIPyV and HPyV9

BACKGROUND

Immunosuppression due to pregnancy may lead to higher susceptibility to infections and reactivation of latent infections, such as BK polyomavirus (BKPyV). There is lack of information about the prevalence of novel human polyomavirus 9 (HPyV9), WU (WUPyV) and KI (KIPyV) during pregnancy.

OBJECTIVES

To study whether pregnancy results in higher prevalence of HPyV9, WUPyV, KIPyV and their correlation with BKPyV.

STUDY DESIGN

Plasma, urine and throat swab samples from 100 pregnant and 100 non pregnant women were screened for the presence of WUPyV, KIPyV, HPyV9 and BKPyV by PCR.

RESULTS

No WUPyV DNA was detected in plasma, urine and respiratory samples from pregnant and non pregnant women. KIPyV DNA was found in two plasma samples from non pregnant women (2%) and not detected in other samples from neither pregnant nor non pregnant women. HPyV9 DNA was determined in all sample types of pregnant and non pregnant women, respectively. There were no significant differences between pregnant and non pregnant women in HPyV9 DNA frequencies for plasma (2% vs. 6%), urine (3% vs. 2%) and respiratory samples (2% vs. 2%). Prevalence of BKPyV in urine samples was significantly higher (p=0.039) in pregnant women (13%) then in non pregnant women (4%); co infection with KIPyV and/or HPyV9 was not detected.

CONCLUSIONS

In contrast with BKPyV, infection with WUPyV, KIPyV and HPyV9 was not detected more frequently during pregnancy. To the best of our knowledge HPyV9 was detected first in respiratory samples in our study.

Association between the JC polyomavirus infection and male infertility

In recent years the incidence of male infertility has increased. Many risk factors have been taken into consideration, including viral infections. Investigations into viral agents and male infertility have mainly been focused on human papillomaviruses, while no reports have been published on polyomaviruses and male infertility. The aim of this study was to verify whether JC virus and BK virus are associated with male infertility. Matched semen and urine samples from 106 infertile males and 100 fertile males, as controls, were analyzed. Specific PCR analyses were carried out to detect and quantify large T (Tag) coding sequences of JCV and BKV. DNA sequencing, carried out in Tag JCV-positive samples, was addressed to viral protein 1 (VP1) coding sequences. The prevalence of JCV Tag sequences in semen and urine samples from infertile males was 34% (72/212), whereas the BKV prevalence was 0.94% (2/212). Specifically, JCV Tag sequences were detected in 24.5% (26/106) of semen and 43.4% (46/106) of urine samples from infertile men. In semen and urine samples from controls the prevalence was 11% and 28%, respectively. A statistically significant difference (p<0.05) in JCV prevalence was disclosed in semen and urine samples of cases vs. controls. A higher JC viral DNA load was detected in samples from infertile males than in controls. In samples from infertile males the JC virus type 2 strain, subtype 2b, was more prevalent than ubiquitous type 1. JCV type 2 strain infection has been found to be associated with male infertility. These data suggest that the JC virus should be taken into consideration as an infectious agent which is responsible for male infertility.

Seroepidemiology of WU polyomavirus among children exposed perinatally to HIV-1

WU polyomavirus (WUPyV), a new member of the genus wukipolyomavirus in the family Polyomaviridae, has been detected in serum and tissues of individuals infected with HIV. However, the epidemiology of WUPyV among children exposed perinatally to HIV-1 is unknown. To investigate the epidemiology of WUPyV in children exposed to and infected perinatally with HIV, serum samples from 150 children exposed to HIV and 114 children infected with HIV were screened for IgG antibodies to WUPyV. A subset was screened for IgM antibodies to WUPyV. Both antibody detection assays were performed using a recombinant WUPyV VP1-based ELISA. The overall seroprevalence of WUPyV IgG was 76.3% in children infected with HIV and 62% in children exposed perinatally to HIV. In the group of children infected with HIV, the prevalence of WUPyV IgG antibody reached its peak in 2-3 year olds (90.9%). In children 0-5 months of age, IgG seroprevalence was lower in those children exposed to HIV compared to children infected with HIV (43.1% vs.75%, P = 0.047). However, the seroprevalence of WUPyV IgM antibody was higher in children exposed to HIV compared to infants infected with HIV (27.4% vs. 8.3%, P = 0.044). WUPyV infection is acquired in early childhood in the majority of children born to mothers infected with HIV. The implication of this infection and the specific clinical syndrome that it produces, if any, remain to be defined.

BK polyomavirus with archetypal and rearranged non-coding control regions is present in cerebrospinal fluids from patients with neurological complications

BK polyomavirus (BKPyV) has recently been postulated as an emerging opportunistic pathogen of the human central nervous system (CNS), but it is not known whether specific strains are associated with the neurotropic character of BKPyV. The presence of BKPyV large T-antigen DNA was examined in 2406 cerebrospinal fluid (CSF) samples from neurological patients with suspected JC polyomavirus infection. Twenty patients had a large T-antigen DNA-positive specimen. The non-coding control region (NCCR) of the BKPyV strains amplified from CSF from these 20 patients, strains circulating in renal and bone marrow transplant recipients and from healthy pregnant women was sequenced. The archetypal conformation was the most prevalent in all groups and 14 of the neurological patients harboured archetypal strains, while the remaining six patients possessed BKPyV with rearranged NCCR similar to previously reported variants from non-neurological patients. Transfection studies in Vero cells revealed that five of six early and four of six late rearranged promoters of these CSF isolates showed significantly higher activity than the corresponding archetypal promoter. From seven of the neurological patients with BKPyV DNA-positive CSF, paired serum samples were available. Five of them were negative for BKPyV DNA, while serum from the remaining two patients harboured BKPyV strains with archetypal NCCR that differed from those present in their CSF. Our results suggest that NCCR rearrangements are not a hallmark for BKPyV neurotropism and the dissemination of a rearranged NCCR from the blood may not be the origin of BKPyV CNS infection.

Individuals infected with JC polyomavirus do not present detectable JC virus DNA in oropharyngeal fluids

JC virus (JCV) is ubiquitous in the human population. Primary infection normally occurs during childhood and is followed by a lifelong persistent infection. The main mode of transmission remains unknown. Several authors have hypothesized that JCV transmission occurs through the respiratory route, and that respiratory secretions could represent a possible source of viral particles. The present study intended to evaluate oropharyngeal fluids from patients infected with JCV, in order to ascertain if respiratory secretions could indeed constitute a source of exposure to this polyomavirus. Oropharyngeal washing samples from 25 patients co-infected with JCV and human immunodeficiency virus type 1 were evaluated for the presence of JCV DNA. Regardless of the titre of antibodies or the presence of viral urinary excretion, JCV genome was not detected in oropharyngeal samples collected from any of the patients infected with JCV included in this study, which may suggest that oropharyngeal fluids are an unlikely source for JCV infection.

Age-specific seroprevalence of Merkel cell polyomavirus, BK virus, and JC virus

We produced capsids of Merkel cell polyomavirus (MCPyV) in a baculovirus expression system and developed a virus-like particle (VLP) enzyme-linked immunosorbent assay (ELISA). To determine age-specific seroprevalence, serum samples were collected from 947 individuals attending hospital outpatient clinics and ranging in age from 1 to 93 years. To evaluate the association between exposure to MCPyV and Merkel cell cancer (MCC), plasma samples were obtained from 33 MCC patients and 37 controls. MCPyV seroprevalence was 45% in children under 10 years of age, increased to 60% in the next decade of life, and peaked at 81% among those 60 to 69 years of age. Levels of MCPyV capsid antibodies were positively correlated with age (P = 0.007). Virus specificity of MCPyV seroreactivity was supported by competitive inhibition of reactivity by MCPyV VLPs and not by BK polyomavirus (BKPyV) VLPs. MCPyV seroprevalence was greater among MCC patients (91%) than controls (68%; age-adjusted P value, 0.32); the mean level of MCPyV antibodies was also greater (P = 0.04). The age-specific seroprevalence of MCPyV shares with previously known polyomaviruses, BKPyV and JC polyomavirus (JCPyV), evidence of widespread exposure in human populations beginning early in life. MCPyV age-specific seroprevalence also has unique features. Seroprevalence among children is higher than that of JCPyV but lower than that of BKPyV. Among older adults, MCPyV seroprevalence remains high, while that of BKPyV declines and that of JCPyV continues to rise. In agreement with results from other studies, we found an association between MCPyV seropositivity and MCC, and higher levels of serum MCPyV capsid antibodies in MCC patients than in controls.