Objective      To explore the cross-interference effect of toll-like receptor 9 (TLR9) anta-gonist CpG-c41 on TLR7-MyD88-dependent pathway.        Methods      The levels of TNF-α and IL-6 in the supernatants of RAW264.7 cells (supplied with CpG-c41 simultaneously) treated with TLR7 agonist ssRNA83 were measured by ELISA at 24 h

and IκBα expression mediated by TLR7-MyD88-dependent pathway was assayed by Western blotting. CpG-c41-mediated immune protection of ssRNA83 attacked BALB/c mice was observed according to detection of serum levels of TNF-α and IL-6 by ELISA at 2 h.       Results      The results of in vitro and in vivo experiments demonstrated that the expression levels of TNF-α and IL-6 were all significantly inhibited (P0.01). The results of in vitro experiment showed a dose-dependent inhibition

and Western blotting results showed that CpG-c41 could interfere with the degradation of IκBα mediated by TLR7-MyD88-dependent pathway.        Conclusion      CpG-c41 has a cross-interference effect on the degradation of IκBα mediated by TLR7-MyD88-dependent pathway

which consequently inhibits the release of pro-inflammatory cytokines

and protects  mice against ssRNA attacking.