Enhanced susceptibility of G6PD‐deficient human fibroblast to enterovirus 71 infection

Abstract

Accumulating evidence suggests that cellular redox status plays an important role in regulating viral replication and infectivity. Glucose 6-phosphate dehydrogenase (G6PD) deficient fibroblast has been shown to suffer higher oxidative stress than normal control part. To further delineate how oxidative stress may affect cellular susceptibility to viral infection, experiments were performed to compare the susceptibility of normal (HFF3) and G6PD-deficient (HFF1) cells to enterovirus71 (EV71) infection. After EV71 infection, both types of cells developed cytopathic effect. Using MTT assay, there was a significant difference in cell viability in both types of cells after 48h post-infection: cell viability of HFF1 was 38% of uninfected control whereas the viability of HFF3 was 52% of uninfected control. The amount of viral particles collected from HFF1 was 2 fold higher than that of HFF3 at 48h post-infection. In the immunofluorescence assay, virus production of HFF1 was much higher than that of HFF3. The level of the viral gene (3C) expression was increased by more than 2 folds in G6PD-deficient cells as compared to normal cells by quantitative PCR. The GSH/GSSG ratio in HFF1 was lower than HFF3. Furthermore ectopic expression of G6PD in the deficient cells increased their viability upon viral infection reduced viral replication and increased GSH/GSSG ratio. Moreover, pre-treatment antioxidant, such as Epigallocatechin gallate (EGCG) or Pistacia weinmannifolia (PW), was able to increase cell viability in both types of cells following EV71 infection. Taken together, these data support our hypothesis that G6PD-deficient cells are highly susceptible to EV71 infection and antioxidants treatment can reduce the loss of cell viability upon EV71 infection.