Genetic dissection of TLR9 reveals complex regulatory and cryptic proinflammatory roles in mouse lupus.

ABSTRACT: In lupus, Toll-like receptor 7 (TLR7) and TLR9 mediate loss of tolerance to RNA and DNA, respectively. Yet, TLR7 promotes disease, while TLR9 protects from disease, implying differences in signaling. To dissect this 'TLR paradox', we generated two TLR9 point mutants (lacking either ligand (TLR9^K51E) or MyD88 (TLR9^P915H) binding) in lupus-prone MRL/lpr mice. Ameliorated disease of Tlr9^K51E mice compared to Tlr9^-/- controls revealed a TLR9 'scaffold' protective function that is ligand and MyD88 independent. Unexpectedly, Tlr9^P915H mice were more protected than both Tlr9^K51E and Tlr9^WT mice, suggesting that TLR9 also possesses ligand-dependent, but MyD88-independent, regulatory signaling and MyD88-mediated proinflamm

SUBMITTER: Leibler C 

PROVIDER: S-EPMC9561083 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature