JCV Reactivation Research Articles

Role for tumor necrosis factor-alpha in JC virus reactivation and progressive multifocal leukoencephalopathy

JCV causes the CNS demyelinating disease progressive multifocal leukoencephalopathy (PML). After primary infection, JCV persists in a latent state, where viral protein expression and replication are not detectable. NF-κB and C/EBPβ regulate the JCV promoter via a control element, κB, suggesting proinflammatory cytokines may reactivate JCV to cause PML, e.g., in HIV-1/AIDS. Since HIV-1 induces cytokines in brain, including TNF-α, we examined a role for TNF-α in JCV regulation. TNF-α stimulated both early and late JCV transcription. Further, the κB element conferred TNF-α response to a heterologous promoter. Immunohistochemistry of HIV+/PML revealed robust labeling for TNF-α and TNFR-1. These data suggest TNF-α stimulation of κB may contribute to JCV reactivation in HIV+/PML.

JC Virus Latency in the Brain and Extraneural Organs of Patients with and without Progressive Multifocal Leukoencephalopathy

JC virus (JCV) is latent in the kidneys and lymphoid organs of healthy individuals, and its reactivation in the context of immunosuppression may lead to progressive multifocal leukoencephalopathy (PML). Whether JCV is present in the brains or other organs of healthy people and in immunosuppressed patients without PML has been a matter of debate. We detected JCV large T DNA by quantitative PCR of archival brain samples of 9/24 (38%) HIV-positive PML patients, 5/18 (28%) HIV-positive individuals, and 5/19 (26%) HIV-negative individuals. In the same samples, we detected JCV regulatory region DNA by nested PCR in 6/19 (32%) HIV-positive PML patients, 2/11 (18%) HIV-positive individuals, and 3/17 (18%) HIV-negative individuals. In addition, JCV DNA was detected in some spleen, lymph node, bone, and kidney samples from the same groups. In situ hybridization data confirmed the presence of JCV DNA in the brains of patients without PML. However, JCV proteins (VP1 or T antigen) were detected mainly in the brains of 23/24 HIV-positive PML patients, in only a few kidney samples of HIV-positive patients, with or without PML, and rarely in the bones of HIV-positive patients with PML. JCV proteins were not detected in the spleen or lymph nodes in any study group. Furthermore, analysis of the JCV regulatory region sequences showed both rearranged and archetype forms in brain and extraneural organs in all three study groups. Regulatory regions contained increased variations of rearrangements correlating with immunosuppression. These results provide evidence of JCV latency in the brain prior to severe immunosuppression and suggest new paradigms in JCV latency, compartmentalization, and reactivation.

JC Virus Infection of the Brain

Since its initial description, there have been significant changes in the epidemiology, pathogenesis, and clinical and imaging manifestations of JCV infection of brain. The most common clinical manifestation is PML. Other recently described CNS manifestations are JCE, JCVGCN, and JCM. Although AIDS is the most common predisposing factor for JCV reactivation, there is increasing incidence of brain manifestations of JCV reactivation in non-HIV settings, including different rheumatologic, hematologic, and oncologic conditions; monoclonal antibody therapy; transplant recipients; primary immunodeficiency syndromes; and even in patients without any recognizable immune deficiency. IRIS may develop secondary to restoration of immunity in HIV-positive patients with PML receiving antiretroviral therapy. This is of profound clinical significance and needs to be diagnosed promptly. Imaging plays a crucial role in the diagnosis of the disease, monitoring of treatment response, identifying disease progression, and predicting prognosis. In this article, current understanding of the epidemiology, pathogenesis, clinical presentations, and all aspects of imaging of JCV infection of the brain have been comprehensively reviewed.

Reactivation of Human Herpesvirus-6 in Natalizumab Treated Multiple Sclerosis Patients

The α4 integrin antagonist natalizumab was shown to be effective in patients with immune-mediated disorders but was unexpectedly associated with JC polyomavirus associated progressive multifocal leukoencephalopathy (PML) in two multiple sclerosis (MS) and one Crohn's disease patients. Impaired immune surveillance due to natalizumab treatment may have contributed to the JCV reactivation. As HHV-6 has been suggested to play a role in MS, we asked whether this virus could also have been reactivated during natalizumab therapy. Matched sera and CSF from a limited set of MS patients treated with and without natalizumab were examined for evidence of HHV-6. In addition, we also superinfected a persistent JC virus infected glial cell with HHV-6A to determine if JC virus can be increased. Elevated serum HHV6 IgG and HHV-6A DNA was detected in the CSF of a subset of patients but not controls. We confirmed that superinfection with HHV-6 of a JC virus infected glial cells increased expression of JCV. These results support the hypothesis that treatment with natalizumab may be associated with reduced immune surveillance resulting in reactivation of viruses associated with MS pathogenesis.

Molecular epidemiology characterization of the urinary excretion of polyomavirus in healthy individuals from portugal—a Southern European population

The human polyomaviruses--BKV and JCV--are members of Polyomaviridae family and after primary infections they persist as latent infection especially in the kidneys. BKV reactivation is mainly related to urinary tract diseases and JCV reactivation can induce the disease progressive multifocal leukoencephalopathy. The aim of our study was to characterize the excretion of polyomaviruses in urine samples of healthy individuals from a Portuguese population. We analyzed 498 DNA samples using PCR-RFLP, the sequence amplified consisted in 176 or 173 bp within the antigen T region. Our results indicate that 23.9% of the samples were positive for JCV, 1.8% positive for BKV and 74.3% of the individuals were negative for both viruses. We observed an increased prevalence of JCV shedding in male individuals in comparison to female (P = 0.026). Furthermore, the shedding of both polyomaviruses was influenced by the age of individuals with a significant increase in individuals with more than 56 years old (P = 0.005). Our results show that the shedding of polyomavirus in urine of healthy individuals is highly variable between genders, is influenced by age and differs from region to region. Further studies are needed to evaluate the prevalence of polyomaviruses in healthy individuals, in order to understand the biological behaviour of these viruses.

A case of ureteral lesions in a renal transplant recipient with a co-infection of BK virus and JC virus

Sir, Most cases of Polyomavirus-associated nephropathy are due to BKV, although Randhawa [1] demonstrated the co-infection of JCV and BKV in renal transplant recipients with interstitial nephritis and Kazory [2] and Wen [3] described two cases of interstitial nephritis associated with JCV in the absence of BKV. We report a 65-year-old female who developed ureteral lesions with a co-infection of BKV and JCV. This patient underwent cadaver renal transplantation in November 2005, after four years of haemodialysis for chronic renal failure secondary to diabetes mellitus. The patient received immunosuppressive therapy with tacrolimus, mycophenolate mofetil and corticosteroids. On day 9 post-transplant, cystography showed a urinary fistula, for which a conservative management was initially chosen. On day 12, PCR assay showed a negative result for serum BKV-DNA and JCV-DNA and urine BKV-DNA and demonstrated a viral load of 10 2 JCV-DNA copies/ml on urine. On day 51 a pyeloureteral anastomosis was performed, as no definitive resolution of the leakage was achieved. During surgery, ureteral stricture and detachment were observed. Histological investigation showed cystic ureteritis and mild chronic inflammation of the wall. Neither nuclear findings consistent with viral infection nor positive reaction for SV40 antibody (Lee Biomolecular Res. Labs, CA) were present. PCR on ureteral specimen showed a viral load of 10 3 and 10 8 BKV- and JCV-DNA copies/m go f extracted DNA, respectively. The patient’s clinical conditions and allograft function worsened; a transplantectomy was performed on day 65. Histological investigation of the explanted kidney revealed an acute microabscessual pyelonephritis due to Candida albicans, a small infarction and cystic pyelitis. Notwithstanding immunosuppression withdrawal, transplantectomy, and anti-fungal therapy, clinical conditions did not improve and the patient died on day 83. No autopsy was performed. Some authors have suggested that BKV and JCV reactivation are controlled by distinct mechanisms, hypothesising a protective effect of BKV with regard to JCV [4]. In our patient, both BKV- and JCV-DNA were detected on ureteral specimen, with JCV load being higher than BKV load. However, a histological examination of the explanted kidney did not show the presence of viral inclusions in uroepithelial cells. The discrepancy between morphological and molecular findings could be due to sampling, although it cannot be excluded that the affected cells were detached in the ulcerated areas. However, we could not unequivocally prove a cause and effect relationship between ureteral damage, PCR positivity and allograft dysfunction and failure. Based on these observations, we think a close monitoring of polyomaviruses DNA serum and urine levels should be recommended, to diagnose a viral reactivation in its early stages in kidney graft recipients and to perform a quantitative PCR on tissue samples when a biopsy is executed, even if serum and urine have previously tested negative.

Propagation and assay of the JC virus.

The human polyomavirus, JCV, is the etiological agent of a fatal central nervous system (CNS) demyelinating disease known as progressive multifocal leukoencephalopathy, or PML. Seroepidemiological studies have indicated that greater than 70% of the human population worldwide is infected with JCV. Like other polyomaviruses, JCV establishes a lifelong latent or persistent infection in its natural host (, , , , ). Reactivation of JCV in the setting of an underlying immunosuppressive illness, such as AIDS, leads to virus dissemination to the CNS, infection of oligodendrocytes, and the development of PML (,,,). Not surprisingly, the incidence of PML has increased dramatically as a result of the AIDS pandemic. A recent epidemiological study has found that PML increased twentyfold from 0.2 cases per million people in 1979 to 3.3 cases per million people in 1994 (). The increase in PML has renewed an interest in studying the biology of this common human polyomavirus.

Human polyomavirus JC latency and reactivation status in blood of HIV-1-positive immunocompromised patients with and without progressive multifocal leukoencephalopathy.

Human polyomavirus JC (JCV) induces human progressive multifocal leukoencephalopathy (PML) in patients with AIDS. Peripheral blood mononuclear cells (PBMC) of HIV-1-positive immunocompetent and immunocompromised patients can harbour JCV genome, but their precise role in JCV latency or reactivation status before the onset of PML remains hypothetical. To assess JCV latency or reactivation status in PBMC of HIV-1-positive immunocompromised patients without PML. A group of 82 HIV-1-positive immunocompromised patients who did not have PML were compared with 10 patients with AIDS and PML and with 69 HIV-1-positive immunocompetent patients without PML. DNA and total RNA were extracted from PBMC. The presence of JCV DNA was demonstrated by a semi-nested polymerase chain reaction (PCR). By using primer pairs specific for an early gene,T, and a late gene, VP1, the expression of both early and late gene mRNA in PBMC could be identified using reverse transcriptase (RT) PCR. JCV DNA was detected by PCR in 17.4% of 69 HIV-1-positive immunocompetent patients, in 23.2% of 82 HIV-1-positive immunocompromised patients, and in 60% of 10 patients with AIDS and PML. No correlation could be drawn between the detection of JCV DNA in the PBMC and the clinical or biological status of the HIV-1-positive patients. By using RT-PCR procedures, no expression of JCV early and late mRNA in PBMC was found in any patients. JCV DNA is detectable in the PBMC of 20.5% of 151 HIV-1-infected patients independently of the CDC (Centers for Disease Control and Prevention) stages of the infection. Moreover, our results suggest that active replication of JCV in PBMC appears to be absent or at least a very rare event in HIV-1-positive immunocompromised patients with and without PML.

Evidence That the Soluble Factors Secreted by Activated Immune Cells Suppress Replication of Human Neurotropic JC Virus DNA in Glial Cells

Coordination of the immune response to viral infection and disease in the brain is believed to involve bidirectional interaction between the immune system and the central nervous system (CNS). Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the CNS that generally affects patients exhibiting an immunocompromised condition due to various illnesses. The human polyomavirus, JCV, which infects greater than 70% of the adult population is the etiological agent of this disease. Infection with JCV occurs during childhood and the virus remains in the latent state with no apparent clinical signals. However, under immunocompromised conditions, the virus enters the lytic cycle, and upon cytolytic destruction of glial cells, causes PML. To understand the molecular mechanism underlying immune regulation of JCV replication, we have developed a cell culture system and have investigated the effect of soluble factors from T-cell cultures on replication of JCV DNA in glial cells. Our data demonstrate that replication of JCV DNA in the presence of PMA-stimulated T-cell supernatant is substantially decreased in transfected glial cells. Heat-inactivation and size-fractionation studies revealed participation of a heat labile factor(s) which loses its maximum activity at 60° and ranges between 30 and 100 kDa in size. The unfractionated T-cell supernatant and the fraction enriched in 30- to 100-kDa proteins reduced the level of viral DNA replication during the early phase of the lytic cycle. These observations suggest that regulatory factors which are secreted by immune cells may modulate the level of JCV DNA replication in glial cells. The importance of these observations in reactivation of JCV in immunocompromised individuals and development of PML is discussed.

BK and JC virus infections in recipients of bone marrow transplants.

Fifty-five recipients of bone marrow transplants were monitored prospectively for urinary excretion of BK (BKV) and JC (JCV) viruses and for infections with other viruses. For both BKV and JCV, viruria occurred exclusively in patients who were seropositive at transplantation, a finding indicating that shedding of virus was very likely the result of reactivation. BKV reactivation, which occurred in 26 (55%) of 47 BKV-seropositive patients, was far more common than JCV reactivation, which was detected in only two (7%) of 30 JCV-seropositive patients (P less than .0001). In most patients, BK viruria began two to eight weeks after transplantation and resolved spontaneously after a two- to three-week period. Posttransplantation, there was a temporal pattern in the onsets of infection with the different viruses; herpes simplex virus infections occurred first (mean, 7 d), followed by BKV infections (mean, 33 d) and then cytomegalovirus infections (mean, 51 d). BK viruria was associated with hemorrhagic cystitis.