RNASeq Analysis of Gene Expression in Naïve and Regulatory CD4+ T cells from Wild Type and YAP-deficient mice. RNASeq Analysis of Gene Expression in Naïve and Regulatory CD4+ T cells from Wild Type and YAP-deficient mice

Regulatory T cells (Tregs) are critical for maintaining self-tolerance and immune homeostasis, but their suppressive function can impede effective anti-tumor immune responses. Foxp3 is a transcription factor expressed in Tregs that is required for their function. The pathways and microenvironmental cues governing Foxp3 expression and Treg function are not completely understood. We found that Yes-associated protein (YAP), a co-activator of the Hippo pathway, is highly expressed in Tregs and bolsters Foxp3 expression and Treg function in vitro and in vivo. To assess how YAP influences patterns of gene expression in Tregs, naïve CD4+ T cells and Tregs were isolated from wild type mice and CD4+ T cell lineage-restricted YAP knockout mice (YAPflox/flox, CD4-Cre+). Gene expression by naïve CD4+ T cells and their resting and stimulated Treg counterparts was analyzed by RNASeq. Our findings reveal that YAP ablation undermines expression of multiple genes involved in the TGFβ/SMAD signaling pathway in Tregs including Activin. These findings suggest that YAP potentiates activity along a pro-Treg signaling axis. Overall design: The gene expression patterns in naïve T cells and nTregs from Wild type and YAP cKO (YAP flox/flox,CD4-Cre+) mice were assessed and compared using RNASeq. Sequencing was performed using a Illumina Hiseq2000.

调节性T细胞（Regulatory T cells，简称Tregs）在维持自身耐受与免疫稳态中发挥关键作用，但其抑制功能会阻碍有效的抗肿瘤免疫应答。叉头框蛋白P3（Foxp3）是Tregs中表达的转录因子，对其功能不可或缺。目前对于调控Foxp3表达及Tregs功能的信号通路与微环境信号仍未完全阐明。本研究发现，Hippo通路共激活因子Yes关联蛋白（Yes-associated protein，简称YAP）在Tregs中高表达，并可在体内外增强Foxp3表达及Tregs功能。为探究YAP对Tregs基因表达模式的影响，本研究从野生型小鼠及CD4+ T细胞谱系特异性YAP敲除小鼠（YAPflox/flox, CD4-Cre+）中分离了初始CD4+ T细胞与Tregs。通过RNA测序（RNASeq）分析了初始CD4+ T细胞及其静息、活化对应Treg细胞的基因表达情况。本研究结果显示，YAP敲除会削弱Tregs中多个参与TGFβ/SMAD信号通路的基因的表达，其中包括激活素（Activin）。上述结果表明，YAP可增强促Treg信号轴的活性。实验整体设计：通过RNA测序（RNASeq）对野生型与YAP条件性敲除（YAP cKO，YAP flox/flox,CD4-Cre+）小鼠的初始T细胞及天然调节性T细胞（natural Tregs，简称nTregs）的基因表达模式进行检测与比较。测序使用Illumina Hiseq2000平台完成。