The Rapidly Expanding Family of Human Polyomaviruses: Recent Developments in Understanding Their Life Cycle and Role in Human Pathology

Abstract

Since their discovery in 1971, the polyomaviruses JC (JCPyV) and BK (BKPyV), isolated from patients with progressive multifocal leukoencephalopathy and polyomavirus-associated nephropathy, respectively, remained for decades as the only known members of the Polyomaviridae family of viruses of human origin. Over the past five years, the application of new genomic amplification technologies has facilitated the discovery of several novel human polyomaviruses (HPyVs), bringing the present number to 10. These HPyVs share many fundamental features in common such as genome size and organization. Infection by all HPyVs is widespread in the human population, but they show important differences in their tissue tropism and association with disease. Much remains unknown about these new viruses. In this review, we discuss the problems associated with studying HPyVs, such as the lack of culture systems for the new viruses and the gaps in our basic understanding of their biology. We summarize what is known so far about their distribution, life cycle, tissue tropism, their associated pathologies (if any), and future research directions in the field.

Viruses and Human Cancers: a Long Road of Discovery of Molecular Paradigms

“…Thus, it is perhaps likely that unknown viruses exist that are associated with human cancers and may be identified in the future. In this regard, the number of members of the family of human polyomaviruses has expanded rapidly in recent years, and the roles of most of these in human diseases remain unknown (57).…”

“…The most recent human oncogenic virus to be discovered is Merkel cell polyomavirus (MCV) (56), the only proven oncogenic virus of the many human polyomaviruses (57). The role of animal polyomaviruses in tumorigenesis has long been known, and two human polyomaviruses, JC virus (JCV) and BK virus (BKV), were identified in 1971 (58)(59)(60).…”

“…The role of animal polyomaviruses in tumorigenesis has long been known, and two human polyomaviruses, JC virus (JCV) and BK virus (BKV), were identified in 1971 (58)(59)(60). More recently, at least eight new human polyomaviruses have been discovered (57), and one of these, MCV, was identified in patients with Merkel cell carcinoma (MCC), which is a rare but highly aggressive malignancy. MCC is a neuroectodermal tumor that is may arise from the mechanoreceptor Merkel cells of the skin (61).…”

Detección de polyomavirus BK y JC en extractos leucocitarios de sangre periférica de pacientes con infección por VIH del área norte de Santiago

“…Varios estudios han mostrado material gené-tico amplificado de BKPyV desde orina de individuos inmunocompetentes. Se ha determinado que BKPyV establece una infección persistente, usualmente con niveles indetectables de replicación 7 , pudiendo reactivarse por un estado de inmunosupresión. En pacientes inmunosuprimidos la excreción viral en orina puede relacionarse a cistitis hemorrágica y nefropatía asociada a polyomavirus 8 .…”

A Potential Linkage Between the JC and BK Polyomaviruses and Brain and Urinary Tract Tumors: A Review of the Literature

“…The asymptomatic primary infection occurs in childhood and is usually subclinical; JCV infects approximately 50%-80% of healthy subjects, while the percentage of BKV seroprevalence is approximately 80%-90%. 7 Both JCV and BKV infect and remain latent primarily in the kidney tissue and can reactivate in cases of host immunosuppression. In cases of severe immunodeficiency, JCV can lytically infect oligodendrocytes, causing a fatal demyelinating disease of the central nervous system (CNS) known as PML.…”