Ricerc@Sapienza

John Cunningham virus (JCPyV), a member of the Polyomaviridae family, consists of a circular double-stranded DNA genome composed of an early and a late regions physically separated by the non-coding control region (NCCR). The DNA sequence of the NCCR distinguishes two forms of JCPyV, the designated archetype and the prototype which results from a rearrangement of the archetype sequence. JCPyV is the etiological agent of the progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the brain. PML was originally a rare complication of hematological malignancies; however, the incidence of PML has increased during the HIV epidemic in the 1980s. Recently, PML cases are increasing among patients treated with monoclonal antibodies. Although JCPyV infection is widespread in the population, the mode of transmission is not yet well defined. Virus might enter the mouth or nose and presumably spread by the hematogenous route from the primary site of infection to secondary sites such as kidneys, lymphoid tissues and brain to establish focal areas of infection or persistence. When alteration of the immune system occurs, viral infection emerges. Although rearrangement of NCCR of archetype JCPyV is thought to be an important event in the pathogenesis of PML, little is known regarding what induces this rearrangement. To date, the cell culture systems to propagate JCPyV archetype have been very limited in their availability and robustness. Prior to this study, it has been demonstrated that JCPyV archetype DNA replicates in COS-7 cells expressing SV40 TAg and HIV-1 Tat. Based on these observations, the present study is addressed: 1) to produce an in vitro model in COS-7 and SVGp12 cells to study JCPyV DNA replication, 2) to analyze NCCR rearrangements during the viral cycle, 3) to define NCCR rearrangements as possible viral biomarkers for an early PML diagnosis.