白蛋白亲和肽-黑色素瘤抗原肽胶束淋巴结的靶向性研究

Study on targeting lymph nodes of the micelle from albumin binding domain and melanoma antigen peptide

目的 制备环状白蛋白亲和肽-黑色素瘤抗原肽（cABD-Trp2）胶束,探究胶束与白蛋白的亲和力及其淋巴结的靶向性。方法 具白蛋白亲和性的环状多肽序列与抗原肽共价连接后,在水溶液中自组装成cABD-Trp2胶束,利用透射电镜观察其形态和粒径;通过非变性聚丙烯酰胺凝胶电泳、荧光能量共振转移、生物膜层干涉技术来考察胶束与白蛋白间的亲和性;经荧光成像系统来考察cABD-Trp2胶束在体内对淋巴结的靶向性。结果 成功制备了cABD-Trp2胶束,其形态为不规则的球形,粒径约25 nm。胶束形成后仍能与白蛋白亲和,与游离抗原或弗氏不完全佐剂载抗原比较,胶束能显著提高抗原对淋巴结的靶向性。结论 白蛋白亲和多肽与抗原肽形成胶束后仍能与白蛋白有效亲和,通过内源性白蛋白,可使抗原有效传递到淋巴结,为疫苗设计提供了新思路。

OBJECTIVE To prepare micelle, which was constructed by albumin binding domain （ABD） and melanoma antigen peptide Trp2. To evaluate the affinity between micelle and albumin, and the ability of micelle to targeting lymph nodes. METHODS In aqueous solution, the micelle was self - assembled due to covalent conjugation of ABD and Trp2. The shape and size were measured by transmission electron microscopy. The affinity of mlcelle and albumin was proved by Native polyacrylamide gel electrophoresis, Fluo- rescence resonance energy transfer and Biological film interference technology. The in vivo ability to target lymph nodes was evaluated by fluorescent imaging system. RESULTS The micelle based on ABD and Trp2 was successfully prepared and the size of spheroid micelle was 25 nm. After conjugation with Trp2 and formed micelle, the ABD still had affinity with albumin. Compared with free Trp2 and Trp2 in IFA, micelle significantly enhanced the targeting of lymph nodes. CONCLUSION The micelle formed by ABD and Trp2 reserves the affinity to albumin. Attributing to the carriage of endogenous albumin, the micelle was able to target lymph nodes,providing a new idea in vaccine design.