miR-148a controls metabolic programming and survival of mature CD19-negative plasma cells. miR-148a controls metabolic programming and survival of mature CD19-negative plasma cells

Long-lived antibody-secreting plasma cells are essential to establish humoral memory against pathogens. While a plasma cell gene signature has been established, elaborate key regulators remain enigmatic.The plasma cell signature microRNA miR-148a favors in vitro differentiation of plasmablasts by repressing the germinal center transcription factor Bach2 and pro-apoptotic BIM and PTEN. To determine whether miR-148a fine-tunescontrols the in vivo development of B cells into long-lived plasma cells, we established mice with a genomic, conditional and inducible deletion of miR-148a. The analysis of miR-148a-deficient mice revealed reduced serum Ig, decreased numbers of newly formed plasmablasts and a reduced CD19-negative, CD93-positive long-lived plasma cells compartment. RNASeq and metabolic analysis showed an impaired glucose uptake and oxidative phosphorylation-based energy metabolism, altered abundance of homing receptors CXCR3 (increase) and CXCR4 (reduction) in miR-148a-deficient plasma cells. These findings establish the importance of miR-148a as a regulator of the differentiation and maintenance of late CD19-negative mature plasma cells by controlling their metabolism and retention in the bone marrow niche. clearly undermine our model of miR-148a as a regulator of the maintenance of long-lived plasma cells. Overall design: RNASeq of WT and miR148a(-/-) bone marrow plasma cells (TACI+ CD138+)

长寿命抗体分泌浆细胞（long-lived antibody-secreting plasma cells）是建立针对病原体的体液免疫记忆的核心要素。尽管已确立浆细胞基因特征谱，但阐明其关键调控因子仍颇具挑战。既往研究显示，微小RNA miR-148a（microRNA miR-148a）可通过抑制生发中心转录因子Bach2以及促凋亡蛋白BIM与PTEN，在体外促进成浆细胞的分化。为明确miR-148a是否在体内调控B细胞向长寿命浆细胞的发育过程，我们构建了可实现基因组水平条件性诱导性敲除miR-148a的小鼠模型。对miR-148a缺陷型小鼠的分析结果显示，其血清免疫球蛋白水平降低，新生成浆细胞数量减少，且CD19阴性、CD93阳性的长寿命浆细胞亚群比例下降。RNA测序（RNASeq）与代谢分析表明，miR-148a缺陷型浆细胞存在葡萄糖摄取受损、基于氧化磷酸化的能量代谢异常，同时归巢受体CXCR3的丰度上调、CXCR4的丰度下调。上述研究证实，miR-148a可通过调控代谢水平与骨髓微环境滞留能力，调控晚期CD19阴性成熟浆细胞的分化与维持，这一结论明确修正了我们此前对miR-148a作为长寿命浆细胞维持调控因子的认知模型。整体实验设计：对野生型（WT）与miR148a敲除（miR148a(-/-)）小鼠的骨髓浆细胞（TACI+ CD138+）进行RNA测序。