Coxsackie B1 virus infection enhances the bacterial invasiveness, the phagocytosis and the membrane permeability in HEp-2 cells.

To analyze the effect of coxsackie B1 virus infection on bacterial invasiveness, phagocytosis and cytoplasma membrane permeability, we have studied invasiveness of Shigella flexneri, unspecific phagocytosis of latex particles and release of the non-metabolizible amino acid, alpha-aminoisobutyric acid (AIB). Virus infection enhanced invasiveness of S. flexneri and phagocytosis of latex beads and increased plasma membrane permeability as measured by release of AIB. The effect on all three functions increased with virus concentration, but the kinetics were different. During the early phase of virus infection there was no difference between the effect on invasiveness, phagocytosis and permeability in cell cultures pretreated with viable or with UV-inactivated virus. However, after 6 h, 5 h and 2 h respectively, there was an increased response in cell cultures pretreated with viable virus compared to cells inoculated with UV-inactivated virus. The results indicate that the virus effect on bacterial invasiveness is a function of several parameters, including phagocytosis and membrane function changes.