DNA免疫吸附柱配基免疫原性的研究

Evaluation of immunogenicity of the DNA ligand of DNA immunoadsorbent

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。

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 DNA group,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 had no 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 significant differences among three groups(F=1.183,P=0.336). No pathological change and lymphadenosis was found by histopathology results. Conclusions The DNA ligand of DNA immunoadsorbent cannot stimulate rabbits to produce specific antibodies,nor stimulate the lymphadenosis in immunized rabbits. The DNA ligand has no immunogenicity.