Mitochondria Activity and CXCR4 Collaboratively Promote the Differentiation of CD11c + B Cells Induced by TLR9 in Lupus.

Lupus is characterized by the autoantibodies against nuclear Ags, underscoring the importance of identifying the B cell subsets driving autoimmunity. Our research focused on the mitochondrial activity and CXCR4 expression in CD11c + B cells from lupus patients after ex vivo stimulation with a TLR9 agonist, CpG-oligodeoxyribonucleotide (ODN). We also evaluated the response of CD11c + B cells in ODN-injected mice. Post- ex vivo ODN stimulation, we observed an increase in the proportion of CD11c hi cells, with elevated mitochondrial activity and CXCR4 expression in CD11c + B cells from lupus patients. In vivo experiments showed similar patterns, with TLR9 stimulation enhancing mitochondrial and CXCR4 activities in CD11c hi B cells, leading to the generation of anti-dsDNA plasmablasts. The CXCR4 inhibitor AMD3100 and the mitochondrial complex I inhibitor IM156 significantly reduced the proportion of CD11c + B cells and autoreactive plasmablasts. These results underscore the pivotal roles of mitochondria and CXCR4 in the production of autoreactive plasmablasts.