The JC virus-like particle transportes into nuclear

Objective: To determine whether the JC virus-like particles (VLP) can enter the nuclear as an intact particle. Methods: The nuclear transport of VLP consisting of recombinant major capsid proteins VP1 were investigated. HeLa or SVG cells were incubated with fluorescein isothiocyanate(FITC)-labeled VLPs containing packaged Cy3 and nucleus import of VLPs were examined with confocal microscopy. Results: When the cells were inoculated with FITC-labeled VLPs containing packaged Cy3, the FITC and Cy3 signals exhibited similar temporal and spatial patterns of accumulation in the nucleus of either HeLa or SVG cells. In contrast, when HeLa or SVG cells were inoculated with mixture of dissociated FITC-labeled VP1 and Cy3, the Cy3 signal was not detected within cells, even though FITC was detected in nucleus. VLPs containing packaged Cy3 were subjected to SDS-PAGE and the gel was analyzed by CBB staining for VP1 and with a fluorescence imager for Cy3 respectively, that Cy3 did not bind covalently to VP1 was confirmed as revealed by VP1 and Cy3 migrated to different positions. These findings indicated that the virion structure of VLP was preserved during transportion into the nucleus. When HeLa or SVG cells were incubated with VLPs containing packaged DNA, the DNA was detected using PCR within cytoplasm and nuclear, indicated that nuclear entrance of the VLP is not different from JCV. Conclusion: The JCV VLP transported into nuclear in intact particle that is as same as VLP.