LL37/self-DNA complexes mediate monocyte reprogramming.

LL37 alone and in complex with self-DNA triggers inflammatory responses in myeloid cells and plays a crucial role in the development of systemic autoimmune diseases, like psoriasis and systemic lupus erythematosus. We demonstrated that LL37/self-DNA complexes induce long-term metabolic and epigenetic changes in monocytes, enhancing their responsiveness to subsequent stimuli. Monocytes trained with LL37/self-DNA complexes and those derived from psoriatic patients exhibited heightened glycolytic and oxidative phosphorylation rates, elevated release of proinflammatory cytokines, and affected naïve CD4 ⁺ T cells. Additionally, KDM6A/B, a demethylase of lysine 27 on histone 3, was upregulated in psoriatic monocytes and monocytes treated with LL37/self-DNA complexes. Inhibition of KDM6A/B reversed the trained immune phenotype by reducing proinflammatory cytokine production, metabolic activity, and the induction of IL-17-producing T cells by LL37/self-DNA-treated monocytes. Our findings highlight the role of LL37/self-DNA-induced innate immune memory in psoriasis pathogenesis, uncovering its impact on monocyte and T cell dynamics.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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