MICROINJECTION OF HEP-2 CELLS WITH COXSACKIE B1 VIRUS-RNA ENHANCES INVASIVENESS OF SHIGELLA-FLEXNERI ONLY AFTER PRESTIMULATION WITH UV-INACTIVATED VIRUS

Coxsackie B1 virus induces increased susceptibility to invasion by Shi gella flexneri when HEp-2 cells are inoculated with the complete virus . When RNA from the same virus was microinjected into cells, virus RNA was synthesized and new virus particles were formed, but the transfec ted RNA had no effect on bacterial invasiveness. However, when the cel ls were prestimulated with UV-inactivated virus, the microinjected RNA induced an additional enhancement of bacterial invasiveness. Microinj ected whole virus particles did not replicate and did not induce any c hange in bacterial invasiveness. The results indicate that an initial event in virus multiplication is necessary to achieve an effect of tra nsfected viral RNA on invasion of S. flexneri.