Paradoxical effects of chondroitin sulfate-E on Japanese encephalitis viral infection

► sCS-E inhibited JEV infection in non-neural cells by interfering with viral attachment. ► sCS-E enhanced viral infection in neural cells, despite that viral attachment to the cells is inhibited by sCS-E. ► sCS-E increased viral RNA replication in neural cells. ► The enhancement effect of sCS-E is also observed in a rat infection model.