Fig. 1

Affected microglial taxis in acute brain slices by capsules and PLY. a Schematic diagram of the acute brain slice perfusion system (top) and the cut surface interface, where the taxis of Iba1-stained microglia was analyzed (bottom). b The number of microglia recruited to the surface of the slices was significantly greater in slices exposed to bacterial lysates from double mutant (PLY and capsule-deficient (∆PLY∆Cps)) bacteria versus mock-treated slices. c Significant reduction in the substantial taxis of microglial cells towards the slice surface in the ∆PLY∆Cps group once PLY expression (∆Cps), capsule expression (∆PLY), or both (PLY and capsule) expressions (D39) were restored. Scale bars, 30 μm. d Similar protein levels of MIF in homogenates from acute brain slices 6 h after mock challenge or exposure to D39 bacterial lysates. All values represent the mean ± SEM, n = 8 slices from six animals in three experimental series (a–c), n = 6 slices (d). *p < 0.05, **p < 0.01, ***p < 0.001. In all bacterial lysis experiments, the lysate concentration was 70 million CFU/ml