Preferential localization of the Epstein-Barr virus (EBV) oncoprotein LMP-1 to nuclei in human T cells: implications for its role in the development of EBV genome-positive T-cell lymphomas.
The Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP-1) is thought to play a role in the EBV-induced B-cell transformation and immortalization. EBV has also been implicated in certain human T-cell lymphomas; however, the phenotypic effects of the expression of this oncoprotein in T cells are not known. To learn whether LMP-1 also induces phenotypic changes in T cells, we stably expressed it in human cell lines of T and B lineages and 25 LMP-1-expressing T-cell clones and 7 B-cell clones were examined. Our results show for the first time that, in sharp contrast to B cells, LMP-1 preferentially localizes to nuclei in T cells and does not induce the phenotypic changes in these cells that it induces in B cells, does not associate with TRAF proteins, and does not arrest the cell cycle in the G2/M phase. A computer-assisted analysis revealed that LMP-1 lacks the canonical nuclear localization signal. Our results suggest that this oncoprotein may not play the same role in the lymphomagenesis of T cells as it does in B cells.
Xu
Jingwu
J
Laboratory of Immunovirology, Department of Microbiology and Immunology, University of Montreal and Ste-Justine Hospital, Montreal, Quebec, Canada H3T 1C5. ahmada@justine.umontreal.ca
Ahmad
Ali
A
Menezes
José
J
D001402:B-Lymphocytes / Q000378:metabolism / Q000502:physiology / Q000821:virology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D016679:Genome, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D016399:Lymphoma, T-Cell / Q000821:virology*; D013601:T-Lymphocytes / Q000378:metabolism / Q000502:physiology / Q000821:virology*; D014162:Transfection; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*
C037662:EBV-associated membrane antigen, Epstein-Barr virus; D014763:Viral Matrix Proteins