Fig. 4

IRF3KO mice show reduced proinflammatory changes in the brain after repeated LPS challenges. A Schematic of the 4 day repeated LPS challenge paradigm. B Representative images of FACS analysis showing presence of significantly more infiltrating myeloid cells in Quadrant 2 (Q2)(CD11b⁺,CD45^high) in the WT-LPS group in addition to the microglia population (CD11b⁺,CD45.^intermediate) in Q3. C-D Quantification of the percentage and absolute cell count of infiltrating cells shows that LPS-induced infiltration of myeloid cells was markedly reduced in the IRF3KO-LPS mice compared to the WT-LPS. N = 5,6 each group. The parent population is defined as live cells based on DAPI staining. E–F Quantification of the levels of mean fluorescence intensity of CD11b gated on the microglia in Q3 shows a more significant increase in WT-LPS microglia compared to IRF3KO-LPS microglia. N = 5,6 each group. G, I Representative images of western blots showing increased astrocyte proliferation in LPS-treated WT and IRF3KO samples in the cortical lysates. Quantification shows that the extent of astrocyte proliferation is significantly lower in IRF3KO mice compared to the WT. N = 9,10 each group.H, J Representative images and quantification of western blots showing a significant increase in the hippocampi of pro-IL1β (full length) and cleaved-IL1β indicate activation of inflammasome in LPS-treated WT samples. Quantification shows that IRF3KO mice are protected from this increase. N = 9,10 each group. Two-way ANOVA with Tukey’s multiple comparisons. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001