JC virus multiplication in human hematopoietic progenitor cells requires the NF-1 class D transcription factor.
JCV, a small DNA virus of the polyomavirus family, has been shown to infect glial cells of the central nervous system, hematopoietic progenitor cells, and immune system lymphocytes. A family of DNA binding proteins called nuclear factor-1 (NF-1) has been linked with site-coding specific transcription of cellular and viral genes and replication of some viruses, including JC virus (JCV). It is unclear which NF-1 gene product must be expressed by cells to promote JCV multiplication. Previously, it was shown that elevated levels of NF-1 class D mRNA were expressed by human brain cells that are highly susceptible to JCV infection but not by JCV nonpermissive HeLa cells. Recently, we reported that CD34(+) precursor cells of the KG-1 line, when treated with the phorbol ester phorbol 12-myristate 13-acetate (PMA), differentiated to cells with macrophage-like characteristics and lost susceptibility to JCV infection. These studies have now been extended by asking whether loss of JCV susceptibility by PMA-treated KG-1 cells is linked with alterations in levels of NF-1 class D expression. Using reverse transcription-PCR, we have found that PMA-treated KG-1 cells express mRNA that codes for all four classes of NF-1 proteins, although different levels of RNA expression were observed in the hematopoietic cells differentiated into macrophages. Northern hybridization confirms that the expression of NF-1 class D gene is lower in JCV nonpermissive PMA-treated KG-1 cells compared with non-PMA-treated cells. Further, using gel mobility shift assays, we were able to show the induction of specific NF-1-DNA complexes in KG-1 cells undergoing PMA treatment. The binding increases in direct relation to the duration of PMA treatment. These results suggest that the binding pattern of NF-1 class members may change in hematopoietic precursor cells, such as KG-1, as they undergo differentiation to macrophage-like cells. Transfection of PMA-treated KG-1 cells with an NF-1 class D expression vector restored the susceptibility of these cells to JCV infection, while the transfection of PMA-treated KG-1 cells with NF-1 class A, B, and C vectors was not able to restore JCV susceptibility. These data collectively suggest that selective expression of NF-1 class D has a regulatory role in JCV multiplication.
Monaco
M C
MC
Laboratory of Molecular Medicine and Neuroscience, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
Sabath
B F
BF
Durham
L C
LC
Major
E O
EO
D015152:Blotting, Northern; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D004268:DNA-Binding Proteins; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000821:virology*; D006801:Humans; D007577:JC Virus / Q000472:pathogenicity / Q000502:physiology*; D008264:Macrophages / Q000378:metabolism / Q000821:virology; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013755:Tetradecanoylphorbol Acetate; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014779:Virus Replication; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D013755:Tetradecanoylphorbol Acetate