A Dipalmitoylated Lipoprotein from Mycoplasma pneumoniae Activates NF-κB through TLR1, TLR2, and TLR61

The pathogenesis of Mycoplasma pneumoniae infection is considered to be in part attributed to excessive immune responses. Recently, lipoproteins from mycoplasmas have been reported to induce NF-κB activation. In this study, we examined the ability of lipoproteins from M. pneumoniae to activate NF-κB, and the active component responsible for the NF-κB activation was identified. Lipid-associated membrane proteins from M. pneumoniae were found to induce NF-κB through TLR 2 in a human monocytic cell line, THP-1. The active component of the Lipid-associated membrane proteins was a subunit b of F0F1-type ATPase (F0F1-ATPase). The F0F1-ATPase is assumed to contain two palmitic acids. The activation of NF-κB by the F0F1-ATPase was inhibited by a dominant negative construct of TLR1 and TLR6. These results indicate that the activation of NF-κB by F0F1-ATPase is dependent on TLR1, TLR2, and TLR6. The activity of the F0F1-ATPase was decreased with pretreatment of lipoprotein lipase but not protease, indicating that the lipid moiety of the F0F1-ATPase was important for the NF-κB activation. Thus, a dipalmitoylated lipoprotein from M. pneumoniae was found to activate NF-κB through TLR1, TLR2, and TLR6.