Sequencing and Analysis of JC Virus DNA From Natalizumab-Treated PML Patients

Abstract

Background. Progressive multifocal leukoencephalopathy (PML) in natalizumab-treated MS patients is linked to JC virus (JCV) infection. JCV sequence variation and rearrangements influence viral pathogenicity and tropism. To better understand PML development, we analyzed viral DNA sequences in blood, CSF and/or urine of natalizumab-treated PML patients.Methods. Using biofluid samples from 17 natalizumab-treated PML patients, we sequenced multiple isolates of the JCV noncoding control region (NCCR), VP1 capsid coding region, and the entire 5 kb viral genome.Results. Analysis of JCV from multiple biofluids revealed that individuals were infected with a single genotype. Across our patient cohort, multiple PML-associated NCCR rearrangements and VP1 mutations were present in CSF and blood, but absent from urine-derived virus. NCCR rearrangements occurred in CSF of 100% of our cohort. VP1 mutations were observed in blood or CSF in 81% of patients. Sequencing of complete JCV genomes demonstrated that NCCR rearrangements could occur without VP1 mutations, but VP1 mutations were not observed without NCCR rearrangement.Conclusions. These data confirm that JCV in natalizumab-PML patients is similar to that observed in other PML patient groups, multiple genotypes are associated with PML, individual patients appear to be infected with a single genotype, and PML-associated mutations arise in patients during PML development.

Natalizumab treatment for multiple sclerosis: updates and considerations for safer treatment in JCV positive patients

“…Much less frequently, the rearranged form of JCV can be found in the urine of patients experiencing asymptomatic reactivation 13 . In addition to RR, variability in VP1 sequences found in CSF and brain of PML patients, but not in urine, also reinforces the relationship between the variants or genetic changes and viral tropism 14,15 . Currently, the most accepted idea is that PML arises as a consequence of reactivation of latent JCV in the kidneys, leading to viremia and as a consequence, viruses present in blood and/or B-lymphocytes enter the brain and cause disease.…”

Immunological biomarkers identifying natalizumab-treated multiple sclerosis patients at risk of progressive multifocal leukoencephalopathy

“…In support of this hypothesis, it should be also taken into account that JCV mutations have been associated to PML in natalizumabtreated patients (Reid et al, 2011). In this context, a long lasting decrease of the thymic output, on one hand, depletes the peripheral T-cell compartment of the repertoire diversity necessary for an effective antigen recognition; on the other hand it increases repertoire restrictions in the CSF .…”

“…Viral mutations, facilitating the infection of oligodendroglial cells, together with modifications of the immune system composition, appear to be required for latent JCV to become pathogenic (Weissert, 2011). Indeed, in natalizumab-treated patients, mutations in the coding regions of the viral capsid protein VP1 and in the non-coding control region of the virus (Reid et al, 2011) have been associated with PML. Furthermore, additional secondary effects of natalizumab on immune cells other than its ability to inhibit the crossing of the blood brain barrier have also been documented (Stüve, 2008;Koudriavtseva et al, 2014).…”

An animal model for progressive multifocal leukoencephalopathy

“…ably, the authors were able to demonstrate an evolution of viral sequences during disease progression in these mice that reflected the biology of disease in PML patients. Moreover, infection of the chimeric mice with JCV mutants derived from human patients also led to viral spread and disease (30,31). This latter point is interesting, as mutant virus arising in human patients seems unable to recognize sialic acid-containing receptors for the virus (32,33).…”