Figure 2

Microglia are activated by conditioned media from BDV-infected astrocytes. A – Mixed cultures were mock-or BDV-infected and stained with GFAP and BDV antibodies and lectin at 14 days p.i. Note that the astrocyte monolayer is a dominating cell surface in culture, providing bedding for microglia and neurons. Infected neurons can be identified as bright red round cells (white arrow). Many astrocytes are infected (yellow arrows). Note the absence of BDV infection of microglia (green stain). Scale bar – 50 μm. B – The numbers of round-shape activated microglia in 14 DIV mixed cultures infected on the 2nd DIV (white column); exposed to 2-day old conditioned media collected from BDV-infected astrocytes on the 10th DIV (gray column), or exposed to heat-inactivated media collected from BDV-infected astrocytes (black column). Each bar represents mean ± SEM (n = 5–12 experiments). The data are presented as the number of round microglia cells in BDV versus mock-treated sister mixed cultures. The results of the paired t-test on two populations (mock vs. mean) are shown as asterisks (*p < 0.05; **p < 0.005) Scale bar – 50 μm