Fig. 3

Supernatant from infected microglia, but not from infected astrocytes or FBBC-1 cells, induces bovine PMN chemotaxis. Donor cows from which PMN were extracted to conduct chemotaxis assays in each represented experiment are indicated in two columns in the lower right panel. Statistical analyses: Mann–Whitney U tests (**P < 0.01; ****P < 0.0001; ns non-significant). A PMN chemotaxis toward astrocyte-conditioned medium (Astrocyte sup.) and medium from astrocytes infected with WT-Lm (Astrocyte Lm sup.), in comparison with medium alone and bovine IL-8. Data are represented as means on a superimposed scatter dot plot of 5 independent experiments, each performed in triplicates. B PMN chemotaxis toward FBBC-1-conditioned medium (FBBC-1 sup.) and medium from FBBC-1 infected with WT-Lm (FBBC-1 Lm sup.), in comparison with medium alone and bovine IL-8. Data are represented as means on a superimposed scatter dot plot of 7 independent experiments, each performed in triplicates. C PMN chemotaxis toward microglia-conditioned medium (Microglia sup.) and medium from microglia infected with WT-Lm (Microglia Lm sup.), in comparison with medium alone and bovine IL-8. Microglia-conditioned medium exerts modest chemotaxis on bovine PMN, and the chemotactic effect increased upon infection of microglia. Data are represented as means on a superimposed scatter dot plot of 5 independent experiments, each performed in triplicates