Fig. 5

L. murinus promotes macrophage activation and IFN-I responses to IBV infection. a Frequency of a panel of macrophages in PBMC of mock or infected SPF or ABX chicken (n = 6), gavaged with L. murinus at 5dpi following IBV inoculation. b Expression of MHC-II on PBMC macrophages from mock or infected SPF or ABX chicken, gavaged with L. murinus or control at 5 dpi following IBV inoculation. c Peripheral blood of ABX chicken (n = 6) gavaged with Lactobacillus was harvested and tested for viral loads at 5 dpi using qRT-PCR. d Viral loads of peripheral blood of infected L. murinus-gavaged ABX chicken (n= 6) injected with clodronate liposomes. e IFN-β levels in the serum of ABX chicken gavaged with L. murinus gavaged at 5 dpi following IBV infection as detected by ELISA. f Fold change of IFN-β and ISG expression in PBMC and the spleen of SPF or ABX chicken (n = 6) gavaged with L. murinus at 5 dpi following IBV infection relative to respective mock controls. g IFN-β levels in the serum of ABX chicken gavaged with L. murinus ABX chicken (n = 6) injected with IFNAR antibody. h Viral loads of peripheral blood of ABX chicken (n = 6) gavaged with L. murinus injected with IFNAR antibody. i Viral loads of peripheral blood or kidney of gnotobiotic chicken (n = 6) gavaged with L. murinus injected with IFNAR antibody. Data are from three independent experiments. Biological replicates for each sample are three. P values were determined using a one-way analysis of variance; ns, not significant; **P < 0.01