A common single nucleotide polymorphism in the CD14 promoter decreases the affinity of Sp protein binding and enhances transcriptional activity
A common single nucleotide polymorphism in the CD14 promoter decreases the affinity of Sp protein binding and enhances transcriptional activity
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DOI：
10.4049/jimmunol.167.10.5838
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发表时间：
2001-11-15
影响因子：
4.4
通讯作者：
Vercelli, D
中科院分区：
文献类型：
--
作者：
LeVan, TD;Bloom, JW;Vercelli, D
CD14 是一种模式识别受体，通过识别细菌脂聚糖（主要是 LPS）在先天免疫中发挥核心作用。最近，我们的研究小组在CD14近端启动子中发现了一个常见的单核苷酸多态性，-159C→T。 T等位基因的纯合子携带者可溶性CD14显着增加，但血清总IgE减少。这一流行病学证据促使我们研究 CD14/-159C -->T 对单核细胞和肝细胞（已知在体内表达该基因的两种主要细胞类型）中 CD14 调节的影响的分子基础。 EMSA 分析表明，T 等位基因导致含有 Sp1、Sp2 和 Sp3 转录因子结合位点的 GC 盒处 DNA/蛋白质相互作用的亲和力降低。在报告基因检测中，T 等位基因的转录活性在单核 Mono Mac 6 细胞中增加，该细胞表达低水平的 Sp3，Sp3 是 Sp 家族的成员，相对于激活 Sp1 和 Sp2 具有抑制潜力。相比之下，两个等位基因在富含 Sp3 的肝细胞 HepG2 细胞中同等转录。我们的数据表明，CD14 启动子亲和力与 [Sp3]:[Sp1 + Sp2] 比率之间的相互作用在调节两个 CD14 等位基因的转录中发挥着关键的机制作用。先天免疫关键基因的变异可能通过基因与基因和/或基因与环境的相互作用对过敏和炎症性疾病的发病机制很重要。
CD14 is a pattern recognition receptor that plays a central role in innate immunity through recognition of bacterial lipoglycans, primarily LPS. Recently, our group has identified a common single nucleotide polymorphism, -159C -->T, in the CD14 proximal promoter. Homozygous carriers of the T allele have a significant increase in soluble CD14, but a decreased total serum IgE. This epidemiologic evidence led us to investigate the molecular basis for the effects of CD14/-159C -->T on CD14 regulation in monocytes and hepatocytes, the two major cell types known to express this gene in vivo. EMSA analysis showed that the T allele results in decreased affinity of DNA/protein interactions at a GC box that contains a binding site for Spl, Sp2, and Sp3 transcription factors. In reporter assays, the transcriptional activity of the T allele was increased in monocytic Mono Mac 6 cells, which express low levels of Sp3, a member of the Sp family with inhibitory potential relative to activating Sp1 and Sp2. By contrast, both alleles were transcribed equivalently in Sp3-rich hepatocytic HepG2 cells. Our data indicate that the interplay between CD14 promoter affinity and the [Sp3]:[Sp1 + Sp2] ratio plays a critical mechanistic role in regulating transcription of the two CD14 alleles. Variation in a key gene of innate immunity may be important for the pathogenesis of allergy and inflammatory disease through gene-by-gene and/or gene-by-environment interactions.