METHODS: We perform experiments using a rat model of LPS-induced fever. We measure body temperature and explore the functions of peripheral macrophages and PO/AH microglia in fever signaling by ELISA, immunohistochemistry, immunofluorescence, flow cytometry, macrophage depletion, protein blotting, and RNA-seq. Then, the effects of macrophages on microglia in a hyperthermic environment are observed in vitro. Finally, adeno-associated viruses are used to knockdown or overexpress microglia Casp11 in PO/AH to determine the role of Casp11 in fever.
RESULTS: We find peripheral macrophages and PO/AH microglia play important roles in the process of fever, which is proved by macrophage and microglia depletion. By RNA-seq analysis, we find Casp11 expression in PO/AH is significantly increased during fever. Co-culture and conditioned-culture simulate the induction of microglia Casp11 activation by macrophages in a non-contact manner. Microglia Casp11 knockdown decreases body temperature, pyrogenic factors, and inflammasome, and vice versa.
CONCLUSIONS: We report that Casp11 drives fever. Mechanistically, peripheral macrophages transmit immune signals via cytokines to microglia in PO/AH, which activate the Casp11 non-canonical inflammasome. Our findings identify a novel player, the microglia Casp11, in the control of fever, providing an explanation for the transmission and amplification of fever immune signaling.
方法:我们使用LPS诱导的发热大鼠模型进行实验。我们通过ELISA测量体温并探讨外周巨噬细胞和PO/AH小胶质细胞在发热信号中的功能,免疫组织化学,免疫荧光,流式细胞术,巨噬细胞耗竭,蛋白质印迹,和RNA-seq。然后,在体外观察到巨噬细胞在高温环境中对小胶质细胞的影响。最后,腺相关病毒用于敲除或过表达PO/AH中的小胶质细胞Casp11,以确定Casp11在发热中的作用。
结果:我们发现外周巨噬细胞和PO/AH小胶质细胞在发热过程中起重要作用,巨噬细胞和小胶质细胞耗竭证明了这一点。通过RNA-seq分析,我们发现发热期间PO/AH中Casp11的表达显著增加。共培养和条件培养以非接触方式模拟巨噬细胞对小胶质细胞Casp11活化的诱导。小胶质细胞Casp11敲低降低体温,致热因素,和炎性体,反之亦然。
结论:我们报告Casp11引起发烧。机械上,外周巨噬细胞通过细胞因子传递免疫信号给PO/AH中的小胶质细胞,激活Casp11非规范炎性体。我们的发现发现了一个新颖的玩家,小胶质细胞Casp11,在控制发烧中,为发热免疫信号的传递和放大提供解释。