Zhang Feng, Li Yu-hong, Fan Ming-wen, Jia Rong, Xu Qing-an, Guo Ji-hua, Yu Fei, Tian Qi-wei
Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
Acta Pharmacol Sin. 2007 Aug;28(8):1236-42. doi: 10.1111/j.1745-7254.2007.00600.x.
To evaluate the comparative immunogenicity and protective efficacy of the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) fusion anti-caries DNA vaccines pGJA-P/VAX1, pGJA-P, and non-fusion anti-caries DNA construct pGLUA-P in hamsters. In addition, the ability of CTLA-4 to target pGJA-P/VAX1-encoding antigen to dendritic cells was tested in vitro.
All DNA constructs contain genes encoding the A-P regions of a cell surface protein (PAc) and the glucan binding (GLU) domain of glucosyltransferases (GTFs) of cariogenic organism Streptococcus mutans. Human dendritic cells were mixed with the CTLA-4-Ig-GLU-A-P protein expressed by pGJA-P/VAX1-transfected cells and analyzed by flow cytometry. Gnotobiotic hamsters were immunized with anti-caries DNA vaccines by intramuscular injection or intranasal administration. Antibody responses to a representative antigen PAc were assayed by ELISA, and caries protection was evaluated by Keyes caries scores.
A flow cytometric analysis demonstrated that CTLA-4-Ig-GLU-A-P protein was capable of binding to human dendritic cells. pGJA-P/VAX1 and pGJA-P induced significantly higher specific salivary and serum anti-PAc antibody responses than pGLUA-P. Significantly fewer caries lesions were also observed in hamsters immunized with pGJA-P/VAX1 and pGJA-P. There was no significant difference in the anti-PAc antibody level or caries scores between pGJA-P/VAX1 and pGJA-P-immunized groups.
Antigen encoded by CTLA-4 fusion anti-caries DNA vaccine pGJA-P/VAX1 could specifically bind to human dendritic cells through the interaction of CTLA-4 and B7 molecules. Fusing antigen to CTLA-4 has been proven to greatly enhance the immunogenicity and protective efficacy of anti-caries DNA vaccines.
评估细胞毒性T淋巴细胞相关抗原4（CTLA-4）融合抗龋DNA疫苗pGJA-P/VAX1、pGJA-P以及非融合抗龋DNA构建体pGLUA-P在仓鼠体内的比较免疫原性和保护效力。此外，在体外测试CTLA-4将pGJA-P/VAX1编码抗原靶向树突状细胞的能力。
所有DNA构建体均包含编码致龋菌变形链球菌细胞表面蛋白（PAc）的A-P区域和葡糖基转移酶（GTFs）的葡聚糖结合（GLU）结构域的基因。将人树突状细胞与pGJA-P/VAX1转染细胞表达的CTLA-4-Ig-GLU-A-P蛋白混合，并通过流式细胞术进行分析。无菌仓鼠通过肌肉注射或鼻内给药方式用抗龋DNA疫苗免疫。通过酶联免疫吸附测定（ELISA）检测对代表性抗原PAc的抗体反应，并通过凯斯龋齿评分评估龋齿保护情况。
流式细胞术分析表明，CTLA-4-Ig-GLU-A-P蛋白能够与人树突状细胞结合。pGJA-P/VAX1和pGJA-P诱导的特异性唾液和血清抗PAc抗体反应明显高于pGLUA-P。在用pGJA-P/VAX1和pGJA-P免疫的仓鼠中也观察到明显更少的龋损。pGJA-P/VAX1免疫组和pGJA-P免疫组之间的抗PAc抗体水平或龋齿评分没有显著差异。
CTLA-4融合抗龋DNA疫苗pGJA-P/VAX1编码的抗原可通过CTLA-4与B7分子的相互作用特异性结合人树突状细胞。已证明将抗原与CTLA-4融合可大大增强抗龋DNA疫苗的免疫原性和保护效力。
