Exosomes from systemic lupus erythematosus (SLE) patients Facilitate the production of inflammatory cytokines in dendritic cells (DCs) by regulating the mTOR signaling.

To study the impact of exosomes from Systemic lupus erythematosus (SLE) individuals on the production of inflammatory cytokines in dendritic cells (DCs) and the underlying mechanism. We extracted exosomes from SLE patients (SLE-exo) and healthy adults (HCs-exo), then we treated exosomes by ultrasound to confirm whether the release of exosomal contents can affect the function of exosomes, finally we treated DCs with the exosomes. According to the ELISA results, comparing to control group, the release of IL-10, IL-6, IL-1β, and IL-12 was elevated by HCs-exo, while the release of IL-10, IL-6, IL-1β, IL-12 and TNF-α was markedly elevated by SLE-exo. And the increased release of cytokines was accompanied by the upregulation of p-P70S6K, p-mTOR, and p-4EBP1. Moreover, compared to SLE-exo-treated DCs, the release of IL-6, IL-12 and TNF-α was repressed by the co-administration of rapamycin, especially the release of IL-6, and the level of p-P70S6K, p-mTOR and p-4EBP1 also was repressed. The qPCR results of exosomes showed that miR-223 was upregulated while miR-25 and miR-let-7a were downregulated in SLE-exo. Even though there are some limitations in our research, but based on these results, we considered that the exosomes from SLE patients may promote the production of inflammatory cytokines in mo-DCs by regulating mTOR signaling.