Fig. 8

Evaluation of the roles of vesicular proteins and LPS in MOMVs-mediated protection. a Determination of LPS contents in MOMVs, polymyxin B-treated MOMVs (PMB_MOMVs) and proteinase K-treated MOMVs (PK_MOMVs) by LAL assay. b Coomassie Brilliant Blue-stained SDS-PAGE analysis detected the protein profiles of MOMVs and PK_MOMVs. The IgG titers of anti-OMPs (c) and anti-LPS (d) in sera from chickens (n = 5) immunized with PBS, MOMVs, PMB_MOMVs and PK_MOMVs. e Survival rates of MOMVs- (50 μg), PMB_MOMVs-(50 μg), PK_MOMVs-(50 μg) and PBS-immunized chickens (n = 10) after the lethal infections of these three APEC serogroups (O1, O2 and O78). *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant; versus the control (PBS)