EPSTEIN-BARR-VIRUS INDUCES ACTIN POLYMERIZATION IN HUMAN B-CELLS

The EBV selectively infects human and primate lymphocytes. This select ive tropism occurs as a result of live virus infection through permiss ive membrane receptors. Once EBV has entered the cell, it induces prol iferation and immortalization of these cells. The mechanism of EBV inf ection, however, remains largely unknown. We demonstrate here that a t ransforming strain, but not a nontransforming strain, of EBV stimulate s the conversion of globular actin (G-actin) to filamentous actin (F-a ctin), a process that has been associated with activation and transfor mation of other cell types. Preincubation of B cells with botulinum C- 2 toxin or cytochalasin, which block the conversion of G-actin to F-ac tin, resulted in the inhibition of EBV-induced proliferation. These fi ndings indicate that actin rearrangement is essential for infection of B cells by EBV.