Bitter taste receptor T2R14 detects quorum sensing molecules from cariogenic Streptococcus mutans and mediates innate immune responses in gingival epithelial cells
Bitter taste receptor T2R14 detects quorum sensing molecules from cariogenic Streptococcus mutans and mediates innate immune responses in gingival epithelial cells
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DOI：
10.1096/fj.202000208r
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发表时间：
2021-03-01
期刊：
影响因子：
4.8
通讯作者：
Chelikani, Prashen
中科院分区：
文献类型：
--
作者：
Medapati, Manoj Reddy;Singh, Nisha;Chelikani, Prashen
宿主-病原体相互作用在确定疾病的结果中起重要作用。近年来的研究表明，细菌群体感应分子（quorum sensing molecules，QSM）可以与宿主细胞膜蛋白，主要是G蛋白偶联受体（G protein-coupled receptor，GPCRs）相互作用，诱导天然免疫应答。然而，很少有研究检查QSM-GPCR相互作用及其对口腔先天免疫应答的影响。在这项研究中，我们研究了苦味受体T2 R14在感知致龋细菌变形链球菌分泌的感受态刺激肽（CSP）和介导牙龈上皮细胞（GECs）的先天免疫反应中的作用。转录组学和蛋白质印迹分析鉴定T2 R14在GEC中高度表达。我们的数据表明，只有来自S.与CSP-2和CSP-3相比，变形杆菌诱导了强有力的细胞内钙动员。通过使用CRISPR-Cas9，我们证明CSP-1诱导的钙信号传导和细胞因子CXCL-8/IL-8、TNF-α和IL-6的分泌是通过GEC中的T2 R14介导的。有趣的是，在GEC中由CSP-1激活的NF-kB信号传导不依赖于T2 R14。CSP-1致敏的GEC吸引分化的HL-60免疫细胞（dHL-60），并且这种作用在T2 R14敲低的GEC中和在用T2 R14拮抗剂6-甲氧基黄酮（6-MF）致敏的细胞中被消除。我们的研究结果确定S.作为T2 R家族的肽配体的变异蛋白CSP-1。我们的研究建立了致龋S. GECs中的突变体CSP-1和T2 R14导致先天性免疫应答。总的来说，这些发现表明T2 R作为潜在的治疗靶点来调节口腔细菌感染后的先天免疫应答。
Host-pathogen interactions play an important role in defining the outcome of a disease. Recent studies have shown that the bacterial quorum sensing molecules (QSM) can interact with host cell membrane proteins, mainly G protein-coupled receptors (GPCRs), and induce innate immune responses. However, few studies have examined QSM-GPCR interactions and their influence on oral innate immune responses. In this study, we examined the role of bitter taste receptor T2R14 in sensing competence stimulating peptides (CSPs) secreted by cariogenic bacterium Streptococcus mutans and in mediating innate immune responses in gingival epithelial cells (GECs). Transcriptomic and western blot analyses identify T2R14 to be highly expressed in GECs. Our data show that only CSP-1 from S. mutans induces robust intracellular calcium mobilization compared to CSP-2 and CSP-3. By using CRISPR-Cas9, we demonstrate that CSP-1 induced calcium signaling and secretion of cytokines CXCL-8/IL-8, TNF-alpha, and IL-6 is mediated through T2R14 in GECs. Interestingly, the NF-kB signaling activated by CSP-1 in GECs was independent of T2R14. CSP-1-primed GECs attracted differentiated HL-60 immune cells (dHL-60) and this effect was abolished in T2R14 knock down GECs and also in cells primed with T2R14 antagonist 6-Methoxyflavone (6-MF). Our findings identify S. mutans CSP-1 as a peptide ligand for the T2R family. Our study establishes a novel host-pathogen interaction between cariogenic S. mutans CSP-1 and T2R14 in GECs leading to an innate immune response. Collectively, these findings suggest T2Rs as potential therapeutic targets to modulate innate immune responses upon oral bacterial infections.