Epstein-Barr virus-induced B-cell transformation: quantitating events from virus binding to cell outgrowth.
Epstein-Barr virus (EBV) infection and growth activation of human B cells is central to virus biology and disease pathogenesis, but is poorly understood in quantitative terms. Here, using virus at defined m.o.i., the different stages of this process at the single-cell level are followed in vitro. Virus binding to the B-cell surface, assayed by quantitative PCR, is highly efficient, particularly at the low m.o.i. values that most likely reflect physiologic events in vivo. However, only 10-15 % of bound virus genomes reach the cell nucleus, as visualized by sensitive fluorescence in situ hybridization (FISH) assay; viral genomes acquired per cell nucleus range from 1 to >10, depending on the m.o.i. Thereafter, despite differences in initial genome load, almost all nuclear genome-positive cells then go on to express the virus-encoded nuclear antigen EBNA2, upregulate the cell activation antigen CD23 and transit the cell cycle. EBNA2-positive cells in the first cycle post-infection then grow out to lymphoblastoid cell lines (LCLs) just as efficiently as do cells limiting-diluted from already established LCLs. This study therefore identifies EBV genome delivery to the nucleus as a key rate-limiting step in B-cell transformation, and highlights the remarkable efficiency with which a single virus genome, having reached the nucleus, then drives the transformation programme.
Shannon-Lowe
Claire
C
CR-UK Institute for Cancer Studies, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
Baldwin
Gouri
G
CR-UK Institute for Cancer Studies, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
Feederle
Regina
R
German Cancer Centre, Department of Virus Associated Tumours, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany.
Bell
Andrew
A
CR-UK Institute for Cancer Studies, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
Rickinson
Alan
A
CR-UK Institute for Cancer Studies, The University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
Delecluse
Henri-Jacques
HJ
German Cancer Centre, Department of Virus Associated Tumours, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany.
D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology*; D049109:Cell Proliferation; D002472:Cell Transformation, Viral; D004854:Herpesvirus 4, Human / Q000276:immunology / Q000502:physiology*; D006801:Humans; D008213:Lymphocyte Activation; D014407:Tumor Cells, Cultured