Monomeric G-Quadruplex-Based CpG Oligodeoxynucleotides as Potent Toll-Like Receptor 9 Agonists
Monomeric G-Quadruplex-Based CpG Oligodeoxynucleotides as Potent Toll-Like Receptor 9 Agonists
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DOI：
10.1021/acs.biomac.0c00679
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发表时间：
2020-09-01
影响因子：
6.2
通讯作者：
Yamazaki, Tomohiko
中科院分区：
文献类型：
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作者：
Tu, Anh Thi Tram;Hoshi, Kazuaki;Yamazaki, Tomohiko
含有未甲基化胞嘧啶-磷酸-鸟嘌呤 (CpG) 基序的合成寡脱氧核苷酸 (ODN) 通过刺激内体 Toll 样受体 (TLR) 9 来触发免疫反应。天然线性 ODN 容易受到核酸酶降解，从而限制了其临床应用。在这里，我们设计了基于单体 G-四联体的 CpG ODN（G4 CpG ODN），其在 G4 结构的中央环区域包含 CpG 基序。单体 G4 CpG ODN 在血清中比线性 ODN 更稳定。含有两个或三个 CpG 基序的单体 G4 CpG ODN 可诱导小鼠巨噬细胞样 RAW264 细胞中免疫刺激细胞因子白细胞介素 (IL)-6、IL-12 和干扰素 (IFN)-β 的产生。我们还表明，CpG 基序的数量以及 CpG 基序和 G 束之间的核苷酸数量定义了 G4 CpG ODN 在激活 TLR9 中的功效。将人外周血单核细胞与 G4 CpG ODN 一起孵育可促进 IL-6 和 IFN-γ 的产生，证实它们对人体免疫细胞的刺激作用。与注射线性 ODN 相比，腹膜内注射 G4 CpG ODN 的小鼠产生更高的血浆 IL-6。这些发现进一步了解了控制 G4 CpG ODN 免疫刺激活性的参数，从而为疫苗佐剂的高效 G4 CpG ODN 的合理设计提供了见解。
Synthetic oligodeoxynucleotides (ODNs) containing unmethylated cytosine-phosphate-guanine (CpG) motifs trigger the immune response by stimulating endosomal Toll-like receptor (TLR) 9. Natural linear ODNs are susceptible to nuclease degradation, thereby limiting their clinical applications. Here, we designed monomeric G-quadruplex-based CpG ODNs (G4 CpG ODNs) containing CpG motifs in the central loop region of the G4 structure. The monomeric G4 CpG ODNs were more stable in serum than the linear ODNs. The monomeric G4 CpG ODNs containing two or three CpG motifs induced the production of immunostimulatory cytokines interleukin (IL)-6, IL-12, and interferon (IFN)-beta in mouse macrophage-like RAW264 cells. We also showed that the number of CpG motifs and the number of nucleotides between the CpG motif and G-tracts define the efficacy of the G4 CpG ODNs in activating TLR9. Incubating human peripheral blood mononuclear cells with G4 CpG ODNs promoted IL-6 and IFN-gamma production, confirming their stimulatory effects on human immune cells. Mice given intraperitoneal injections of G4 CpG ODNs produced higher plasma IL-6 compared with injections of linear ODNs. These findings provide further understanding of the parameters governing the immunostimulatory activity of G4 CpG ODNs, thereby providing insights into the rational design of highly potent G4 CpG ODNs for vaccine adjuvants.