Involvement of cytoskeleton in Junín virus entry.

The early events in Junín virus (JUNV) infection are not thoroughly understood. We have previously shown that JUNV enter cells by clathrin-mediated endocytosis. In this report we examine the role of microfilaments and microtubules during early virus infection. Inhibitory effects of drugs affecting main cytoskeletal components on JUNV entry into Vero cells were analyzed. Drugs that disrupted microfilaments or stabilized microtubules inhibited early steps of virus entry. In contrast, drugs that stabilized microfilaments or depolymerized microtubules were not able to block virus entry very efficiently. Furthermore, real time PCR was performed to detect viral entry and we found more than 10-fold less RNA when microfilaments were depolymerized while a 100-fold diminution was seen when microtubules were stabilized. Taken together our results demonstrate that JUNV relies on an intact actin network during early infection in Vero cells while a dynamic microtubule network is also needed. This represents an important contribution to the characterization of arenavirus multiplication cycle.