Time course of phosphorylation of MAPKs in murine microglial cells. The cells were infected with either the S. suis WT strain or its CPS− mutant (1 × 106 bacteria). Cell extracts were recovered at 15 and 30 min and 1, 2, and 4 h postincubation and were subjected to Western blot analysis using antibodies specific for phospho-MAPKs (p-ERK, p-JNK, and p-p38). Following analysis, the blots were stripped and reprobed with an antibody specific for ERK, JNK, or p38 to verify uniformity in gel loading. The results are representative of three independent experiments. n. i., noninfected cells.