Abstract:

Objective To evaluate the immunogenicity of the DNA ligand of DNA immunoadsorbent by observing the serum antibody production，lymphocyte proliferation and changes in immune organ and tissue in rabbits. Methods Twenty-four healthy rabbits were randomly divided into high-dose DNA group，low-dose DNAgroup，low-dose DNA + adjuvant group，and blank control group，with 6 rabbits in each group. Serum antibody titer was determined by the methods of double agar diffusion and enzyme linked immunosorbent assay（ELISA）. The liver and kidney tissues were collected for pathology observation. The spleen was collected to isolate the lymphocytes，which were divided into double strands DNA experiment group，nonspecific immunostimulator concanavalin（ConA）positive control group and cell culture fluid negative control group. The lymphocytes were cultured in vitro with the peripheral blood lymphocytes of rabbit. Spleen lymphocyte proliferation was observed by methylthiazolyl tetrazolium （MMT）colorimetry. Results The double agar diffusion results showed that double stranded DNA could not stimulate the immune system to produce antibodies in rabbits. ELISA results showed that double stranded DNA hadno immunogenicity，which could not stimulate the production of corresponding antibody（F＝1.183，P＝0.341）.The number of splenic lymphocyte proliferation（A value）in negative control group，DNA experiment group，and positive control group were 0.241±0.040，0.850±0.070，0.576±0.078，respectively，but there were no significantdifferences among three groups（F＝1.183，P＝0.336）. No pathological change and lymphadenosis was found byhistopathology results. Conclusions The DNA ligand of DNA immunoadsorbent cannot stimulate rabbits to producespecific antibodies，nor stimulate the lymphadenosis in immunized rabbits. The DNA ligand has no immunogenicity.

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摘要：

目的 通过观察家兔血清抗体产生情况、淋巴细胞增殖情况及免疫器官组织变化，探讨 DNA 免疫吸附柱配基 DNA 的免疫原性。方法 选择健康家兔 24 只，按随机数字表法分为 DNA 高剂量组、DNA低剂量组、DNA 低剂量加佐剂组、空白对照组，每组 6 只。采用双向琼脂扩散实验和酶联免疫吸附试验 （ELISA）检测血清抗体效价；取肝、肾组织进行病理学观察。取脾脏分离淋巴细胞，分为双链 DNA 实验组、非特异性免疫刺激剂刀豆蛋白（ConA）阳性对照组及细胞培养液阴性对照组，分别与兔外周血淋巴细胞进行体外培养，采用四甲基偶氮唑盐（MTT）比色法观察脾淋巴细胞增殖数。结果 双向琼脂扩散实验结果显示，双链 DNA 不能刺激兔免疫系统产生相应抗体 ；ELISA 检测结果显示，双链 DNA 无免疫原性，不能刺激兔产生相应抗体（F＝1.183，P＝0.341）；阴性对照组、阳性对照组、DNA 实验组脾脏淋巴细胞增殖数（A 值）分别为 0.241±0.040、0.850±0.070、0.576±0.078，3 组间比较差异无统计学意义（F＝1.183，P＝0.336）；组织病理学观察结果提示未见病理改变及淋巴组织增生。结论 DNA 免疫吸附柱配基 DNA 不能刺激兔产生特异性抗体 ；不能刺激免疫后兔淋巴细胞增殖，无免疫原性。

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