DNA amplification in glial cells of progressive multifocal leukoencephalopathy: an image analysis study.
ABSTRACT JC virus (JCV), the agent of progressive multifocal leukoencephalopathy (PML), has been shown by both immunohistochemistry and flow cytometry to be associated with p53 protein stabilization. Since stabilization/inactivation of p53 is associated with the development of genomic instability, abnormal cell DNA contents are to be expected in JCV-infected cells of PML. This work explores that possibility by image analysis evaluation of DNA content in PML-infected oligodendrocytes and bizarre astrocytes. Brain paraffin sections of PML lesions from five adult male patients with the acquired immune deficiency syndrome (AIDS) were treated with the Feulgen technique to obtain a stochiometric staining of DNA and analyzed with a microscope image processor. Inclusion-bearing oligodendrocytes exhibited near tetraploid DNA indices in each of the five cases, whereas atypical astrocytes were in the hypertetraploid range in all cases and were polyploid in four instances. This evidence of DNA amplification in PML glial cells is congruent with the functional abolition of p53 protein in association with JCV infection and lends further support to the role of p53 as a keeper of diploid status and guardian of genomic stability.
SourceAvailable from: María-Teresa Pérez-Gracia[Show abstract] [Hide abstract]
ABSTRACT: The term progressive multifocal leukoencephalopathy (PML) denotes a demyelinating neurological disease caused by oligodendrocyte destruction produced by reactivation of human polyomavirus JC, usually acquired in childhood. The advent of acquired immunodeficiency syndrome (AIDS) has contributed to the marked increase in the frequency of this disease and to incomplete discovery of the complex and close molecular relations between JC and human immunodeficiency virus (HIV). Clinical manifestations are nonspecific and are typical of any demyelinating disease, although PML is more aggressive and has a poor prognosis. Definitive diagnosis is based on histological analysis, but neuroimaging and polymerase chain reaction for JC virus in cerebrospinal fluid can also be used. There is no curative therapy. Autoimmune diseases and, recently, iatrogenic damage by immunosuppressors and monoclonal antibodies, are other causes of this disease.Seminarios de la Fundación Española de Reumatología 01/2009; 10(3):91-99. DOI:10.1016/S1577-3566(09)72131-1
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ABSTRACT: The human JC virus (JCV) is a neurotropic polyomavirus that is the etiologic agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system occurring mainly in patients with advanced HIV infection. JCV is also associated with tumors of the brain and other organs as evidenced from the analysis of clinical samples for the presence of JCV DNA sequences and the expression of viral proteins. In addition, JCV is highly oncogenic in experimental animals and transforms cells in culture. JCV encodes three non-capsid regulatory proteins: large T-antigen,
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ABSTRACT: With the goal of facilitating viral reproduction, cytomegalovirus (CMV) induces changes in the host cell replication machinery. Very little information is available, however, on the effects brought about by CMV on proliferating cell nuclear antigen (PCNA) and Ki-67 expression in infected cells. Fifty-five paraffin-embedded tissue samples (43 gastrointestinal, 10 skin, and 2 kidney biopsies) with both histological and immunohistochemical evidence of CMV infection were investigated for PCNA and Ki-67 expression by the avidin– biotin–peroxidase method. Of the 55 cases studied, 47 were positive for PCNA and 46 for Ki-67. PCNA and Ki-67 immunostaining was more striking in CMV-immunoreactive, inclusion-free cell nuclei, whereas cell nuclei exhibiting well-developed CMV inclusions either showed a weak peripheral signal for both proliferation markers, or were completely negative. Enhanced PCNA and Ki-67 expression appears to be among the changes induced by CMV infection in host cells. Moreover, this induction seems to reach its peak during the earlier phases of CMV infection and abate as the infection proceeds to its inclusion-forming phases, when a sufficiently high viral load would have been attained. © 1998 John Wiley & Sons, Ltd.The Journal of Pathology 01/1998; 184(3):279-282. DOI:10.1002/(SICI)1096-9896(199803)184:33.0.CO;2-4 · 7.33 Impact Factor