Fig. 4
Knockdown of microglial IFNAR signalling attenuates phenotypic and genetic changes in response to peripheral mIFNα administration. a Schematic of treatment protocol. Cx3cr1-CreERT2+/−, Ifnar1fl/fl mice were orally gavaged with either vehicle or tamoxifen. Four weeks post gavage, mice were either sacrificed (for qPCR validation of Ifnar1 knockdown) or treated with mIFNα daily for 7 days and sacrificed. b Cortical microglia from Cx3cr1-CreERT2+/−, Ifnar1fl/fl mice were sorted by FACS and analysed for gene expression of Ifnar1 by qPCR. Ifnar1 qPCR primers were designed to span the floxed region of Exon 10. The tamoxifen-treated (N = 3) CreERT2-positive group showed significant knockdown of Ifnar1 expression compared to the vehicle-treated group (N = 4). c Sorted cortical microglia show significantly decreased ISG expression by ddPCR in the tamoxifen treatment group (N = 6) of Cx3cr1-CreERT2+/−, Ifnarfl/fl mice in comparison to the vehicle treatment group (N = 8). C4b expression was also significantly decreased in the tamoxifen treatment group (N = 3) in comparison to the vehicle treatment group (N = 4). d Knockdown of microglial Ifnar1 in the tamoxifen treatment group (N = 3) reverses the observed region-specific changes in synapse engulfment induced by peripheral mIFNα administration in comparison to the vehicle treatment group (N = 4). e Knockdown of microglial Ifnar1 in the tamoxifen treatment group (N = 3) reverses the observed changes in CD45 and CD68 expression induced by peripheral mIFNα administration, with the exception of CD68 expression in the cerebellum in comparison to the vehicle treatment group (N = 4). Veh., Vehicle; Tam., Tamoxifen; n.s., p > 0.05; *p < 0.05; **p < 0.01; ***p < 0.001; Student’s t test or Mann-Whitney U test, assessed by normality of data distribution