In this study, we first examined the effects of hAAT on the functions of DCs from lupus-prone mice, and we showed that hAAT treatment efficiently inhibited CpG- (TLR9 agonist) induced activation of bone marrow-derived conventional and plasmacytoid DCs as well as the production of pro-inflammatory cytokines. Here, TLR9 is linked to systemic lupus erythematosus.