Figure 6

HSV-1 induces the production of soluble factor(s) by glial cells that elicits neuronal cell damage in a DAI dependent manner. Primary microglia or astrocytes were untreated (0) or transfected with siRNA targeting DAI (siDAI) or scrambled siRNA (siCon). At 72 hours following the transfection protocol, cells were uninfected or infected with HSV-1 (MOI of 1) and cultured for a further 24 hours. Filtered conditioned media from these cells was placed on CATH.a cells and the number of attached neuronal cells was monitored at 4, 8 and 12 hours post-infection prior to assessment of neuronal cell death by trypan blue exclusion at 12 hours post-infection. For comparison purposes neuronal cell attachment and death was assessed following addition of media spiked with recombinant TNF-α (65 pg/ml: +). Data is expressed as mean +/- SEM (n = 3). Asterisks indicate a statistically significant difference in the number of attached cells or degree of cell death from that seen in unstimulated cells while pound symbols indicate a statistically significant difference in these parameters between cells treated with siRNA directed against DAI and those that received scrambled siRNA (p < 0.05).