【摘要】：固有免疫系統(tǒng)是機(jī)體抵抗病原體入侵的第一道防線。天然免疫細(xì)胞通過(guò)其上的模式識(shí)別受體（PRR）識(shí)別微生物的病原體相關(guān)分子模式（PAMP），進(jìn)而經(jīng)由信號(hào)的級(jí)聯(lián)放大誘導(dǎo)I型干擾素和前炎癥細(xì)胞因子的產(chǎn)生來(lái)清除入侵的病原體。Toll樣受體（TLR）是目前研究最多的一類PRR家族。在正常的生理?xiàng)l件下，TLR介導(dǎo)的固有免疫的激活有助于機(jī)體防御病原體的侵襲。但如果這種激活得不到有效的控制，固有免疫系統(tǒng)會(huì)被過(guò)度激活并產(chǎn)生過(guò)量的細(xì)胞因子，，導(dǎo)致炎癥和自身免疫性疾病。為了治療這些疾病，發(fā)展抑制固有免疫過(guò)度激活的藥物是十分必要的。在本室前期工作中，我們發(fā)現(xiàn)一種微衛(wèi)星DNA來(lái)源的抑制性寡核苷酸（ODN）SAT05f（5′-CCTCCTCCTCCTCCTCCTCCTCCT-3′）可以抑制病毒核酸誘導(dǎo)的人PBMC產(chǎn)生IFN-α、保護(hù)小鼠抵抗D-GalN/CpG ODN導(dǎo)致的致死性休克以及減少慢性移植物抗宿主病狼瘡樣小鼠體內(nèi)抗雙鏈DNA抗體的產(chǎn)生。這些研究結(jié)果都展示了SAT05f用于治療過(guò)度免疫激活介導(dǎo)疾病的良好潛力。 在本研究中，我們嘗試發(fā)掘更多的SAT05f的免疫抑制功能并研究SAT05f的構(gòu)效關(guān)系。通過(guò)實(shí)驗(yàn)發(fā)現(xiàn)SAT05f可以抑制CpG ODN誘導(dǎo)的小鼠脾細(xì)胞中B淋巴細(xì)胞的增殖、抑制小鼠脾細(xì)胞中B淋巴細(xì)胞結(jié)合和攝入CpG ODN、抑制CpG ODN誘導(dǎo)的RAW264.7細(xì)胞產(chǎn)生TNF-α、抑制CpG ODN誘導(dǎo)的RAW264.7細(xì)胞中TLR9mRNA表達(dá)的上調(diào)，以及抑制CpG ODN誘導(dǎo)的類pDC細(xì)胞（CAL-1）的激活。此外，250μg劑量的SAT05f可以增加熱滅活菌誘導(dǎo)的膿毒性休克小鼠的生存率。構(gòu)效研究顯示：1）CCT重復(fù)ODN至少要含有8個(gè)CCT單元才能發(fā)揮抑制活性。2）SAT05f的3′末端CCT單元對(duì)于其抑制活性的發(fā)揮是必要的。3）SAT05f的5′末端CCT單元可以被優(yōu)化而獲得活性更強(qiáng)的抑制ODN。這些結(jié)果將有助于發(fā)展一種治療TLR過(guò)度激活介導(dǎo)疾病的抑制性寡核苷酸藥物。
[Abstract]:The innate immune system is the first line of defense against pathogen invasion. Innate immune cells recognize the pathogen-related molecular pattern (PAMP), of microorganisms through the pattern recognition receptor (PRR) on it Toll-like receptor (TLR) (Toll-like receptor) is the most widely studied type of PRR family to eliminate invasive pathogens by inducing the production of interferon I and proinflammatory cytokines by cascade amplification of signals. Under normal physiological conditions, the activation of innate immunity mediated by TLR contributes to the defense against pathogen invasion. But if this activation is not effectively controlled, the innate immune system will be over-activated and produce excessive cytokines, leading to inflammation and autoimmune diseases. In order to treat these diseases, it is necessary to develop drugs that inhibit intrinsic immune hyperactivation. In our previous work, we found that a microsatellite DNA-derived inhibitory oligodeoxynucleotides (ODN) SAT05f (5-CCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCTCCT Protect mice against D-GalN/CpG ODN-induced fatal shock and reduce the production of anti-double-stranded DNA antibodies in lupus-like mice with chronic graft-versus-host disease. These findings demonstrate the good potential of SAT05f in the treatment of diseases mediated by excessive immune activation. In this study, we tried to explore more immunosuppressive functions of SAT05f and study the structure-activity relationship of SAT05f. It was found that SAT05f could inhibit the proliferation of B lymphocytes in mouse spleen cells induced by CpG ODN, inhibit the binding of B lymphocytes to spleen cells in mice and inhibit the production of TNF- 偽 by RAW264.7 cells induced by CpG ODN. It also inhibited the up-regulation of TLR9mRNA expression in RAW264.7 cells induced by CpG ODN and the activation of pDC-like cells (CAL-1) induced by CpG ODN. In addition, 250 渭 g of SAT05f increased the survival rate of septic shock mice induced by thermally inactivated bacteria. Structure-activity studies show that: 1) CCT repeat ODN must contain at least eight CCT units in order to exert inhibitory activity. 2) the 3 'terminal CCT unit of SAT05f is necessary for its inhibitory activity. 3) the 5' terminal CCT unit of SAT05f can perform its inhibitory activity. To obtain a more active inhibition of ODN. by being optimized These results will contribute to the development of an inhibitory oligodeoxynucleotide drug for the treatment of TLR over-activation-mediated diseases.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2012
【分類號(hào)】：R341

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 孫然;含CCT基序的寡核苷酸對(duì)TLR7/9介導(dǎo)的天然免疫應(yīng)答的抑制作用[D];吉林大學(xué);2009年

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