Characterization of Immunostimulatory CpG-Rich Sequences from Different Bifidobacterium Species
Characterization of Immunostimulatory CpG-Rich Sequences from Different Bifidobacterium Species
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DOI：
10.1128/aem.01714-09
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发表时间：
2010-05-01
影响因子：
4.4
通讯作者：
Waligora-Dupriet, Anne-Judith
中科院分区：
文献类型：
--
作者：
Menard, Odile;Gafa, Valerie;Waligora-Dupriet, Anne-Judith
双歧杆菌的有益作用部分归因于其免疫刺激特性。这些免疫刺激特性可能与细菌 DNA 特异的未甲基化 CpG 基序的存在有关，该基序可能通过激活 Toll 样受体 (TLR) 诱导 TH1 反应。使用计算机分析、PCR 扩增和斑点印迹，我们表征了各种双歧杆菌菌株的 CpG 含量，并评估了该属中这些基序的免疫刺激特性和基因组异质性。我们基于五种双歧杆菌菌株的整个基因组序列的计算机研究表明，双歧杆菌基因组包含许多 CpG 基序，包括 5'-嘌呤-嘌呤-CG-嘧啶-嘧啶-3' 和 5'-嘌呤-TCG-嘧啶-嘧啶-3' 基序，以及先前在乳酸菌中鉴定的生物活性序列。我们用长双歧杆菌 NCC2705 鉴定了四个富含 CpG 的序列。 G + C 百分比约为 68% 的两个序列包括 14 和 16 个 CpG 基序。 G + C 百分比约为 60% 的两个序列包含 16 个和 6 个 CpG 基序。这些序列通过 RAW 264.7 巨噬细胞上的 TLR9 刺激模式诱导单核细胞趋化蛋白 1 (MCP-1) 和肿瘤坏死因子 α (TNF-α) 的产生。它们的免疫刺激特性、CpG 基序数量和 G + C 百分比之间无法建立联系。我们研究了 71 个不同来源菌株的种间和种内异质性。这些序列在该属中高度保守。未发现富含 CpG 序列的存在与菌株来源（健康、过敏或早产儿）之间存在联系。双歧杆菌 DNA 中 CpG 基序的高频率可能在共生或益生菌双歧杆菌菌株的免疫刺激特性中发挥重要作用。
The beneficial effects of Bifidobacterium are partly due to its immunostimulatory properties. These immunostimulatory properties may be linked to the presence of unmethylated CpG motifs specific to bacterial DNA, which may induce a TH1 response by activating Toll-like receptors (TLR). Using in silico analyses, PCR amplification, and dot blotting, we characterized the CpG content of various bifidobacterial strains and evaluated the immunostimulatory properties and genomic heterogeneity of these motifs in the genus. Our in silico study, based on entire genome sequences from five bifidobacterial strains, showed that Bifidobacterium genomes contain numerous CpG motifs, including 5'-purine-purine-CG-pyrimidine-pyrimidine-3' and 5'-purine-TCG-pyrimidine-pyrimidine-3' motifs, and biologically active sequences previously identified in lactic acid bacteria. We identified four CpG-rich sequences with Bifidobacterium longum NCC2705. Two sequences with a percent G + C of about 68% included 14 and 16 CpG motifs. Two sequences with a percent G + C of about 60% included 16 and 6 CpG motifs. These sequences induce the production of monocyte chemoattractant protein 1 (MCP-1) and tumor necrosis factor alpha (TNF-alpha) through a pattern of TLR9 stimulation on RAW 264.7 macrophages. No link could be established between their immunostimulatory properties, the number of CpG motifs, and percent G + C. We investigated inter- and intraspecies heterogeneity in 71 strains of various origins. These sequences were highly conserved in the genus. No link was found between the presence of the CpG-rich sequence and the origin of the strains (healthy, allergic, or preterm infants). The high frequency of CpG motifs in the DNA of Bifidobacterium may play an important role in the immunostimulatory properties of commensal or probiotic bifidobacterial strains.