Differential inhibition of host cell RNA synthesis in several picornavirus-infected cell lines.

Patterns of cellular RNA synthesis during poliovirus (types 1,2 and 3) and mengovirus infections in HeLa, HEp-2, Vero and L-cells were investigated by means of high-resolution autoradiography, kinetics of 3H-uridine incorporation, and sucrose gradient centrifugation. Only mengovirus-infected L-cells showed an early and exponential inhibition of hnRNA and rRNA synthesis. The other cell lines tested, whether infected with polio- or mengovirus, exhibited a slowly and linearly decreasing cellular RNA synthesis, with hnRNA production suppressed completely, although somewhat later than in L-cells, and rRNA synthesis continuing at a gradually reduced rate during the entire viral growth cycle. Locations of cleavage steps of rRNA precursor molecules are discussed.