Involvement of the cytoskeleton in Junin virus multiplication.

The role of the cellular cytoskeleton in Junin virus (JV) infection was explored in two ways. Firstly, the action of inhibitors that affect individual cytoskeletal systems (microtubules or microfilaments) selectively was analysed. It was found that perturbations of microtubule or microfilament networks caused by colchicine, nocodazole, nifedipine, EGTA or DMSO strongly affected virion production and viral protein expression at non-cytotoxic concentrations. Secondly, the extent of association of viral proteins and infectious virus particles with the cytoskeletal fraction of monkey Vero cells was determined by using three non-ionic detergents, Triton X-100 (TX-100), NP-40 and octyl glucoside (OG). The cytoskeleton retained nearly 70% of the external JV envelope glycoprotein GP38 and about 40% of the JV nucleoprotein NP, according to TX-100 and OG insolubility results. Furthermore, 1% of the total cell-bound infectivity was detected in the detergent-insoluble fraction, suggesting that cytoskeletal components are involved in the initiation of the assembly and budding processes of JV particles at the plasma membrane.