Epstein-barr virus latent membrane protein (LMP1) induces specific NFkappaB complexes in human T-lymphoid cells

The Epstein-Barr virus (EBV) latent membrane protein (LMP1) is believed to play a crucial role in oncogenesis mediated by this virus. We and others previously showed that LMP1 can induce NFkappaB activity in several non-lymphoid cells and B-lymphoid cell lines. Here we show that LMP1 is also able to efficiently induce NFkappaB in human T-lymphoid and monocytic cells. Specific NFkappaB complexes were detected in the nuclei of transfected Jurkat cells using gel mobility shift assays and Western blot analyses. Using antibodies, we demonstrated that these complexes contain NFkappaB subunits NFkB1, NFkB2, RelA and c-Rel. Our results also showed that the NFkappaB complexes induced by LMP1 are able to bind to the NFkappaB consensus sequence in the promoter of the interleukin-2alpha receptor gene and induce expression from a minimal promoter linked to four tandem copies of this sequence. This suggests a possible mechanism by which LMP1 could induce T-cell activation and proliferation.