A hallmark of systemic lupus erythematosus （SLE） is the consistent production of various auto-antibodies by auto-reactive B cells. Interferon-α（IFN-α） signaling is highly activated in SLE B cells and plays a vit...A hallmark of systemic lupus erythematosus （SLE） is the consistent production of various auto-antibodies by auto-reactive B cells. Interferon-α（IFN-α） signaling is highly activated in SLE B cells and plays a vital role in the antibody response by B cells. Previous studies have shown that CD180-negative B cells, which are dramatically increased in SLE patients, are responsible for the production of auto-antibodies. However, the association between CD180 and IFN-αsignaling remains unknown. In the present study, we explored the effect of CD180 on regulating the activation of IFN-α signaling in B cells. We found that the number of CD180-negative B cells was increased in MRIJMp-Fas（Ipr/Ipr） lupus-prone mice compared with wild-type mice. Phenotypic analysis showed that CD180-negative B cells comprised CD138＋ plasmablast/plasma cells and GL-7＋ germinal center （GC） B cells. Notably, ligation of CD180 significantly inhibited the I FN-α-induced phosphorylation of signal transducer and activator of transcription 2 （STAT-2） and expression of IFN-stimulated genes （ISGs） in a Lyn-PI3K-BTK-dependent manner in vitro. Moreover, ligation of CD180 could also inhibit IFN-α-induced ISG expression in B cells in vivo. Furthermore, the Toll-like receptor 7 and Toll-like receptor 9 signaling pathways could significantly downregulate CD180 expression and modulate the inhibitory effect of CD180 signaling on the activation of I FN-a signaling. Collectively, our results highlight the close association between the increased proportion of CD180-negative B cells and the activation of IFN-α signaling in SLE. Our data provide molecular insight into the mechanism of IFN-α signaling activation in SLE B cells and a potential therapeutic approach for SLE treatment.展开更多
基金This work was supported by a grant from National Natural Science Foundation of China （Project number： 31370899）.
文摘A hallmark of systemic lupus erythematosus （SLE） is the consistent production of various auto-antibodies by auto-reactive B cells. Interferon-α（IFN-α） signaling is highly activated in SLE B cells and plays a vital role in the antibody response by B cells. Previous studies have shown that CD180-negative B cells, which are dramatically increased in SLE patients, are responsible for the production of auto-antibodies. However, the association between CD180 and IFN-αsignaling remains unknown. In the present study, we explored the effect of CD180 on regulating the activation of IFN-α signaling in B cells. We found that the number of CD180-negative B cells was increased in MRIJMp-Fas（Ipr/Ipr） lupus-prone mice compared with wild-type mice. Phenotypic analysis showed that CD180-negative B cells comprised CD138＋ plasmablast/plasma cells and GL-7＋ germinal center （GC） B cells. Notably, ligation of CD180 significantly inhibited the I FN-α-induced phosphorylation of signal transducer and activator of transcription 2 （STAT-2） and expression of IFN-stimulated genes （ISGs） in a Lyn-PI3K-BTK-dependent manner in vitro. Moreover, ligation of CD180 could also inhibit IFN-α-induced ISG expression in B cells in vivo. Furthermore, the Toll-like receptor 7 and Toll-like receptor 9 signaling pathways could significantly downregulate CD180 expression and modulate the inhibitory effect of CD180 signaling on the activation of I FN-a signaling. Collectively, our results highlight the close association between the increased proportion of CD180-negative B cells and the activation of IFN-α signaling in SLE. Our data provide molecular insight into the mechanism of IFN-α signaling activation in SLE B cells and a potential therapeutic approach for SLE treatment.
