Cytoskeleton involvement during human cytomegalovirus replicative cycle inhuman embryo fibroblasts

Several studies indicate that viruses can induce different cytoskeletal mod ifications. The present investigation examines the possible involvement of human embryo fibroblast cytoskeleton in the replication of human cytomegalo virus (HCMV). Significant cytoskeletal modifications occur in infected cell s; specifically, microfilament depolymerization is observed very early duri ng the HCMV replicative cycle, whilst microtubules and intermediate filamen ts do not undergo any change for longer times after infection. Our data focus, in particular, on microfilament depolymerization, which sta rts within the first hour of the replicative cycle, and on the significance of this event, as a CMV-induced mechanism to modify the post-transcription al regulation of cellular gene expression for its own benefit. Among the possible mechanisms exploited by HCMV to induce microfilament mod ifications, one might involve the cellular ADP-ribosylation activity, which is increased by HCMV very early in the infectious cycle. Experiments carri ed out on HCMV-infected cells, in the presence of ADP-ribosylation inhibito rs, seem to confirm this hypothesis.