辅助抑制分子在诱导口服免疫耐受中的增强效果

发布时间：2018-01-01 02:38

本文关键词：辅助抑制分子在诱导口服免疫耐受中的增强效果　出处：《延边大学》2007年硕士论文　论文类型：学位论文

【摘要】： 背景：B7-H1是辅助免疫调节分子B7大家族中的一个，B7家族被熟知为对周围系统免疫调节起着重要作用。最近，新发现B7家族的新成员—B7-H4，发现其对肿瘤细胞特异性T细胞有抑制作用。同时通过口腔投入抗原的研究中发现：机体再次遭遇此同种抗原时免疫力明显下降。前者是免疫调节中起重要作用的因子，后者在动物实验和临床治疗中易行且被广泛应用。对于移植排斥反应，自身免疫性疾病等需要通过降低机体免疫力来治疗的疾病中此类联合应用治疗手段已经成为降低免疫治疗领域中的热点。目的：1)用树枝状细胞株—DC2.4诱导对同种抗原的口服免疫耐受；2)检测B7-H1，B7-H4在诱导口服免疫宽容中的作用；3)检测有免疫调节作用的细胞变化；探讨它们在调节机体免疫中的作用和关系。方法：1)给BALB／C(H-2d)小鼠每天喂食树枝状细胞株—DC2.4(H-2b)，诱导对同种抗原的免疫耐受；2)通过静脉动力进样(hydrodynamic injection)B7-El或B7-H4 DNA，并利用酶联接免疫吸附剂测定(Enzyme-Linked Immunosorbnent Assay ELISA)检测其在血液中分泌的B7-H1或B7-H4蛋白质的量；3)通过检测延迟过敏反应(DTH)和单向混合淋巴细胞反应(mixed lymphocyte reaction，MLR)来检测机体免疫力的变化；4)分离脾细胞，肠系膜淋巴细胞等免疫细胞，进行流式染色，检测细胞群的变化；5)采用逆转录-聚合酶链反应(RT-PCR)，，比较B7-H1，B7-H4注射组和对照组中分别分离免疫细胞，并扩增免疫细胞中的FoxP3基因，并以核基因组的GAPDH作为定量标准物，比较FoxP3基因的表达差异。结果：1)给BALB／C(H-2d)小鼠每天喂食树枝状细胞株—DC2.4(H-2b)，诱导出了对同种异型抗原的免疫耐受(P＜0.01)；2)喂食DC2.4同时注射B7-H1或B7-H4 DNA的群体比较对照组延迟过敏反应明显降低(P＜0.05)，从注射B7-H1或B7-H4 DNA的群体中分离的免疫细胞做的单向混合淋巴细胞反应明显降低(P＜0.05)；3)IFN-γ，IL-5，TNF-α表达水平明显减低(P＜0.05)；4)CD4+CD25+FoxP3+免疫调节T细胞在CD4+细胞群中的百分比明显增高(P＜0.05)；5)CD4+细胞中FoxP3基因的表达对比比较组明显增高(P＜0.05)。结论：1)给予BALB／C小鼠口腔投入树枝状细胞株—DC2.4，可诱导对同种抗原的口服免疫宽容。2)B7-H1，B7-H4在诱导口服免疫宽容中有增强作用。3)用DC2.4诱导免疫宽容并注射B7-H1，B7-H4 plasmid DNA的群体中分离的脾细胞和肠系膜淋巴细胞的增殖能力比较对比组中分离的细胞明显下降。4)B7-H1，B7-H4在诱导口服免疫宽容中的增强作用可能与其对Th1和Th2细胞因子的分泌减少和产生较多的CD4+CD25+FoxP3+免疫调节T细胞有关。
[Abstract]:Background: B7-H1 is a member of the costimulatory immunomodulator B7 family, which is known to play an important role in peripheral immune regulation. A new member of the B7 family, B7-H4, was discovered. It was found that it had inhibitory effect on tumor cell specific T cells. At the same time, it was found in the study of oral antigens that:. When the body encounters this same antigen again, the immunity is obviously decreased. The former is an important factor in immune regulation. The latter is easy and widely used in animal experiments and clinical treatment. Autoimmune diseases and other diseases which need to be treated by reducing immunity have become a hot spot in the field of immunoreduction. Objective: to induce oral immune tolerance to alloantigen by dendritic cell line DC2.4. 2) to detect the role of B7-H1B7-H4 in inducing oral immune tolerance; 3) the changes of immunomodulatory cells were detected. To explore their role and relationship in the regulation of body immunity. Methods BALB / CnH-2d) mice were fed with dendritic cell line -DC2.4H-2b1 every day to induce immune tolerance to the same antigen. 2) hydrodynamic injection)B7-El or B7-H4 DNA were injected by intravenous dynamic sampling. Enzyme-Linked Immunosorbnent Assay ELISAA was determined by enzyme-linked immunosorbent assay. The amount of B7-H1 or B7-H4 protein secreted in blood was measured. 3) delayed hypersensitivity (DTH) and unidirectional mixed lymphocyte reaction (unidirectional mixed lymphocyte reaction) were detected. MLR was used to detect the changes of immunity. 4) spleen cells, mesenteric lymphocytes and other immune cells were isolated, and the changes of cell group were detected by flow cytometry. 5) Immunocytes were isolated and amplified by reverse transcription-polymerase chain reaction (RT-PCR) in B7-H1B7-H4 injection group and control group, respectively. GAPDH of nuclear genome was used as quantitative standard to compare the difference of FoxP3 gene expression. Results (1) BALB / CnH-2d) mice were fed with dendritic cell line -DC2.4 ~ (H-2b) per day, and the immune tolerance to allogenic antigen was induced (P < 0.01). 2) the delayed anaphylaxis was significantly lower in the group fed with DC2.4 and injected with B7-H1 or B7-H4 DNA than that in the control group (P < 0.05). The unidirectional mixed lymphocyte reaction of immune cells isolated from the population injected with B7-H1 or B7-H4 DNA decreased significantly (P < 0.05). 3The expression of IL-5 TNF- 伪 in IFN- 纬 was significantly decreased (P < 0.05). 4the percentage of CD4 CD25 FoxP3 immunomodulatory T cells in CD4 cell group was significantly increased (P < 0.05). The expression of FoxP3 gene in CD4 cells was significantly higher than that in control group (P < 0.05). Conclusion the oral administration of BALB/C mouse oral dendritic cell line -DC2.4can induce oral immunity tolerance to alloantigen. B7-H4 has an enhanced effect in inducing oral immune tolerance. 3) DC2.4 was used to induce immune tolerance and B7-H1 was injected. The proliferation ability of spleen cells and mesenteric lymphocytes isolated from B7-H4 plasmid DNA group was significantly lower than that of control group. The role of B7-H4 in inducing oral immune tolerance may be related to the decrease of Th1 and Th2 cytokines secretion and the production of CD4 CD25 FoxP3. Immune regulatory T cells are involved.
【学位授予单位】：延边大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R392

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