FIGURE 9.
The loss of MyD88 results in differential expression of TLR9 mRNA expression in response to S. aureus, PGN, or LPS. MyD88 KO and WT microglia were seeded at 2 × 106 cells/well in 6-well plates and incubated overnight. The following day, cells were stimulated with either 107 heat-inactivated S. aureus (A), 10 µg/ml PGN (B), or 100 ng/ml LPS (C) for 6, 12, or 24 h, whereupon total RNA was isolated and examined for TLR9 expression by qRT-PCR as described in Materials and Methods. Gene expression levels were calculated after normalizing TLR9 signals against GAPDH and are presented in relative mRNA expression units (mean ± SEM of three independent experiments). Significant differences in TLR9 mRNA expression between unstimulated vs PAMP-treated microglia are denoted with asterisks (*, p < 0.05; **, p < 0.001), whereas significant differences between MyD88 KO vs WT microglia are denoted with a hatched sign (#, p < 0.05; ##, p < 0.001).