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Published on: July 13, 2019
Characterization of JC Polyomavirus Derived from COS-IMRb Cells
Souichi Nukuzuma1, Chiyoko Nukuzuma2, Masanori Kameoka3
1Department of Infectious Diseases, Kobe Institute of Health, Japan.
Abstract:
JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system affecting immunocompromised patients. The study of PML-type JCPyV in vitro has been limited owing to the inefficient propagation of the virus in cultured cells. In this study, we carried out long-term culture of COS-7 cells (designated as COS-IMRb cells) transfected with PML-type M1-IMRb, an adapted viral DNA with a rearranged non-coding control region (NCCR). The JCPyV derived from COS-IMRb cells were characterized by analyzing the viral replication, amount of virus by hemagglutination (HA), production of viral protein 1 (VP1), and structure of the NCCR. HA assays indicated the presence of high amounts of PML-type JCPyV in COS-IMRb cells. Immunostaining showed only a small population of JCPyV carrying COS-IMRb cells to be VP1-positive. Sequencing analysis of the NCCR of JCPyV after long-term culture revealed that the NCCR of M1-IMRb was conserved in COS-IMRb cells without any point mutation. The JCPyV genomic DNA derived from a clone of COS-IMRb-3 cells was detected, via Southern blotting, as a single band of approximately 5.1 kbp without deletion. These findings suggest the potential of using COS-IMRb-3 cells as a useful tool for screening anti-JCPyV drugs.
Insights
JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML). We developed COS-IMRb cells for efficient JCPyV culture, enabling potential drug screening against this opportunistic infection in immunocompromised patients.
Area of Science:
- Virology
- Cell Biology
- Neuroscience
Background:
- JC polyomavirus (JCPyV) is a human pathogen that causes progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease.
- Studying JCPyV in vitro is challenging due to inefficient viral propagation in cell cultures.
- PML predominantly affects immunocompromised individuals, highlighting the need for effective therapeutic strategies.
Purpose of the Study:
- To establish a robust in vitro system for culturing PML-type JCPyV.
- To characterize the viral properties and genetic stability of JCPyV propagated in a novel cell line.
- To evaluate the potential of the developed cell line for antiviral drug screening.
Main Methods:
- Long-term culture of COS-7 cells (COS-IMRb) transfected with adapted JCPyV DNA (M1-IMRb).
- Analysis of viral replication, viral load via hemagglutination (HA) assays, viral protein 1 (VP1) production by immunostaining, and non-coding control region (NCCR) structure via sequencing.
- Detection of JCPyV genomic DNA using Southern blotting.
Main Results:
- COS-IMRb cells supported high-titer propagation of PML-type JCPyV, as indicated by HA assays.
- A small proportion of JCPyV-infected COS-IMRb cells expressed VP1.
- Sequencing confirmed the conservation of the M1-IMRb NCCR without mutations after long-term culture.
- Southern blotting showed intact JCPyV genomic DNA (approx. 5.1 kbp) without deletions in COS-IMRb-3 cells.
Conclusions:
- COS-IMRb cells provide an effective platform for propagating PML-type JCPyV.
- The genetic stability of the JCPyV NCCR is maintained in this cell culture system.
- COS-IMRb-3 cells represent a promising tool for screening anti-JCPyV drugs and developing novel therapeutic interventions for PML.
