Molecular virology of Epstein-Barr virus

Epstein-Barr virus (EBV) interacts with its l:lost in three distinct ways i n a highly regulated fashion: (i) EBV infects human B lymphocytes and induc es proliferation of tile infected cells, (ii) it enters into a latent phase in vivo that follows the proliferative phase, and (iii) it can be reactiva ted giving rise to the production of infectious progeny for reinfection of cells of the same type or transmission of tire virus to another individual. In healthy people, these processes take place simultaneously in different anatomical and functional compartments and are linked to each other in a hi ghly dynamic steady-state equilibrium. The development of a genetic system has paved the way for the dissection of those processes at a molecular leve l that can be studied in vitro, i.e. B-cell immortalization and the lytic c ycle leading to production of infectious progeny. Polymerase chain reaction analyses coupled to fluoresccnt-activated cell sorting has on the other ha nd allowed a descriptive analysis of the virus-host interaction in peripher al blood cells as well as in tonsillar B cells in vivo, This paper is aimed at compiling our present knowledge on the process of B-cell immortalizatio n in vitro as well as in vivo latency and attempts to integrate this knowle dge into the framework of the viral life cycle in vivo.