Chloroquine induces empty capsid formation during poliovirus eclipse.

The poliovirus capsid (160S) is modified during eclipse in HeLa cells, which results in at least three types of particles having sedimentation coefficients of 135, 110, and 80S. The lysosomotropic agent chloroquine redirected the production of eclipse products from 135 and 110S particles (containing RNA) to 80S particles (without RNA). The effect started at 5 microM and was fully developed with 20 microM chloroquine. Viral protein synthesis and virion production remained unaffected. The results show that chloroquine can redirect the processing of input virions without interfering with productive uncoating.