This article traces the discovery of polyomaviruses and outlines investigations, which shed light on potential modes of transmission of this increasingly important group of human pathogens. The pathobiology of the virus is summarized with particular reference to interactions with host cell...

Polyomavirus infection became the focus of epidemiologic studies of cancer several decades ago, soon after the discovery of simian virus 40 (SV40) in 1960 and its ability to induce tumors in experimentally infected animals in 1961. Between 1963 and 2003, eight case-control and eleven cohort...

Infection with BK virus (BKV), a member of the Polyomavirus (PV) family, is ubiquitous, with the virus remaining in a latent form in the kidney and urinary tract.1.2 This infection is usually asymptomatic, but with impairment of the cellular immune system the virus can reactivate and lead to...

Although discovered over thirty years ago, many aspects of the epidemiology of BKV andJCV in the general population, such as the source of infectious virus and the mode oftransmission, are still unknown. Primary infection with both BKV and JCV is usuallyasymptomatic, and so age...

Polyomaviruses [BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40)] have beenknown to be associated with diseases in humans for over thirty years. BKV-associatednephropathy and JCV-induced progressive multifocal leukoencephalopathy (PML) werefor many years rare diseases occurring...

The last decade has witnessed the introduction of several potent immunosuppressiveagents in the field of transplant medicine. Contemporaneously, infection with BK virus (BKV) has emerged as an important complication of immunosuppression and animportant cause of allograft loss after kidney...

In animal studies, polyoma viruses have been found to be viral agents for oncogenesis and to produce a wide range of pathological lesions in experimental animals, including a variety of neoplastic tumors. The human polyoma viruses (JCV and BKV), along with their simian cousin (SV40), are...

In this chapter, polyomaviruses will be presented in an immunological context. Principal observations will be discussed to elucidate humoral and cellular immune responses to different species of the polyomaviruses and to individual viral structural and regulatory proteins. The role of immune...

Measurement of antibody titres to the human polyomaviruses BK and JC has for many years had to rely on Haemagglutination inhibition. In recent years, viral serology based on virus-like particles (VLPs) in enzyme immunoassays (EIAs) has become widely used for a variety of viruses. We sought to...

Polyomaviruses are small, tumorigenic, nonenveloped viruses that infect several different species. Interaction of these viruses with cell surface receptors represents the initial step during infection of host cells. This interaction can be a major determinant of viral host and tissue tropism....

BK virus (BKV), JC virus (JCV) and Simian Virus 40 (SV40) are polyomaviruses, highly homologous at the DNA and protein levels. While the human polyomaviruses BKV and JCV are ubiquitous in humans, SV40 is a simian virus which was introduced in the human population, between 1955 and 1963, by...

Primary contact with the human polyomaviruses (huPyV) is followed by lifelong persistence of viral DNA in its host. The most prominent organs affected are the kidney, the Central Nervous System (CNS )and the hematopoietic system. Under impairment of immune competence limited activation of virus...

We provide in this chapter an overview of the basic steps to reconstruct evolutionary relationships through standard phylogeny estimation approaches as well as network approaches for sequences more closely related. We discuss the importance of sequence alignment, selecting models of evolution,...

Polyomaviruses of the BK- and JC-strains often remain latent within the transitional cell layer of the bladder, ureters and the renal pelvis as well as in tubular epithelial cells of the kidney. Slight changes in the immune status and/or an immunocompromised condition can lead to the...

Polyomaviruses are small, nonenveloped DNA viruses, which are widespread in nature. In immunocompetent hosts, the viruses remain latent after primary infection. With few exceptions, illnesses associated with these viruses occur in times of immune compromise, especially in conditions that bring...

The human neurotropic polyomavirus, JC virus (JCV), is the etiologic agent of progres sive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system that occurs mainly in immunosuppressed patients. JCV has also been found to be associated with human tumors...

Multiple methods have been used to measure antibodies to polyomavirus virions. In order to have a common method for all polyomaviruses, we developed enzyme immunoassays (EIAs) using virus-like-particles (VLPs) produced in the baculovirus expression system. We tested serum samples from humans and...

Polyomavirus allograft nephropathy, also termed BK virus nephropathy (BKN) after the main causative agent, the polyoma-BK-virus strain, is a major complication following kidney transplantation. BKN is the most common viral infection affecting the renal allograft with a reported prevalence of 1%...

Recent advances in stem cell biology have called attention to the role these cells may play in the pathogenesis of systemic and nervous system diseases. Although not capable of indefinite self renewal and pluripotentiality as stem cells are, progenitor cells can give rise to cells of different...

Polyomavirus-associated nephropathy (PVAN) is an emerging disease in renal transplant patients with variable prevalence of 1-10% and graft loss up to 80%. BK virus (BKV) is the primary etiologic agent, but JC virus (JCV) and possibly simian virus SV40 may account for some cases. Intense...

Leflunomide, trade name Arava¨ (Aventis Pharmaceuticals Incorporation, Bridgewater, New Jersey, U.S.A.), belongs to a family of drugs called the malonitrilamides. Some, like leflunomide, have substantial immune suppressive activity in experimental allograft models. In addition to experimental...

The incidence of polyoma virus infection, particularly that of BK virus (BKV) in kidney transplant recipients has been increasing steadily since early 1990s. The diagnosis is generally made by a renal allograft biopsy. However the diagnosis can sometimes be difficult because of the pathological...

Polyomaviruses, as their name indicates, are viruses capable of inducing a variety of tumors in vivo. Members of this family, including the human JC and BK viruses (JCV, BKV), and the better characterized mouse polyomavirus and simian virus 40 (SV40), are small DNA viruses that commandeer a...

The BK Virus (BKV) genome is a double-stranded, circular DNA molecule with genetic organization similar to other polyomaviruses, and high homology to JC Virus (JCV) and SV40. The archetypal form of BKV noncoding regulatory region (NCRR) is the infectious form of BKV that replicates in the...