Enhanced susceptibility of B lymphoma cells to measles virus by Epstein-Barr virus type III latency that upregulates CD150/signaling lymphocytic activation molecule.
Bottom Line: Among EBV-encoded genes, latent membrane protein 1 was responsible for the CD150 upregulation.Furthermore, a cellular regulator of MV replication was implicated that functions in a vaccine strain-specific fashion.Altogether, the MV OVT should serve as an alternative therapy against EBV-positive diffuse large B-cell lymphoma with type III EBV latency.
Affiliation: AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan.Show MeSH
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Mentions: Finally, we sought the EBV latent gene responsible for the upregulation of CD150. We excluded EBNA1 and EBER because no CD150 upregulation was observed in cells with type I EBV latency. Raji and P3HR-1, highly susceptible to MV infection, are infected with defective EBV genetically devoid of EBNA2 and EBNA3, suggesting that these viral proteins are unlikely to be responsible. The signals from interleukin-1β, Toll-like receptor, and CD40, activating both the NF-κB and AP1 pathways, have been reported to upregulate CD150 expression.(43–45) Thus, we focused on the viral oncogene LMP1 because LMP1 is expressed in type III EBV latency and has been shown to activate both NF-κB and AP1.(6,46) The flow cytometric analysis revealed that BJAB cells stably expressing LMP1(46) expressed higher levels of CD150 than the EBV-negative counterparts (Fig. 2b vs Fig. 4a). These findings are consistent with a previous report demonstrating that LMP1 expression resulted in the upregulation of CD150 in a BL cell line Eli.(42) To directly test this working hypothesis, we measured the cell surface levels of CD150 on BJAB LMP1 cells after cells were treated with NF-κB inhibitors that limit the phosphorylation of IκB. Expression of CD150 on BJAB-LMP1 cells was downregulated in a dose-dependent manner after exposure to BAY 11-7082 (Fig. 4b). These data suggest that the upregulation of CD150 was partly due to the transcriptional activation by NF-κB, which was induced by LMP1.
Affiliation: AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan.