Spleen fibroblastic reticular cell-derived acetylcholine promotes lipid metabolism to drive autoreactive B cell responses

Autoreactive B cell responses are essential for the development of systemic lupus erythematosus (SLE). Fibroblastic reticular cells (FRCs) are known to construct lymphoid compartments and regulate immune functions. Here, we identify spleen FRC-derived acetylcholine (ACh) as a key factor that controls autoreactive B cell responses in SLE. In SLE, CD36-mediated lipid uptake leads to enhanced mitochondrial oxidative phosphorylation in B cells. Accordingly, the inhibition of fatty acid oxidation results in reduced autoreactive B cell responses and ameliorated diseases in lupus mice. Ablation of CD36 in B cells impairs lipid uptake and differentiation of autoreactive B cells during autoimmune induction. Mechanistically, spleen FRC-derived ACh promotes lipid influx and generation of autoreactive B cells through CD36. Together, our data uncover a novel function of spleen FRCs in lipid metabolism and B cell differentiation, placing spleen FRC-derived ACh in a key position in promoting autoreactive B cells in SLE.

Automated summary

In this study, researchers find that spleen Fibroblastic Reticular Cells (FRCs) release acetylcholine (ACh) which is a key factor in controlling autoreactive B cell responses in Systemic Lupus Erythematosus (SLE). CD36-mediated lipid uptake in B cells enhances mitochondrial oxidative phosphorylation in SLE. The inhibition of fatty acid oxidation reduces autoreactive B cell responses and improves SLE in lupus mice. The ablation of CD36 in B cells impairs lipid uptake and autoreactive B cell differentiation during autoimmune induction. Mechanistically, spleen FRC-derived ACh promotes lipid influx and generation of autoreactive B cells through CD36.