Microinjection of HEp-2 cells with coxsackie B1 virus RNA enhances invasiveness of Shigella flexneri only after prestimulation with UV-inactivated virus

Abstract

Coxsackie B1 virus induces increased susceptibility to invasion by Shigella 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 transfected RNA had no effect on bacterial invasiveness. However, when the cells were prestimulated with UV‐inactivated virus, the microinjected RNA induced an additional enhancement of bacterial invasiveness. Microinjected whole virus particles did not replicate and did not induce any change in bacterial invasiveness. The results indicate that an initial event in virus multiplication is necessary to achieve an effect of transfected viral RNA on invasion of S. flexneri.

Shigella flexneri adherence to and multiplication in coxsackie B1 virus‐infected HEp‐2 cells

“…Linear regression analysis for intracellular multiplication was performed: the slope of linear regression (colony-forming unitslmin) (+SD) was: 0.810 (0.084) in untreated control cells and 0.770 (0.046) in cells treated with viable virus. The regression correlation coefficient was 0.98 and 0.99. virus (7) or after prestimulation with UV-inactivated virus and subsequent microinjection of viral RNA (9). The prestimulation with UV-inactivated virus induces a moderate enhancement of invasiveness comparable to the effect of complete virus.…”