鱼精蛋白对PLA微球佐剂的调控

Adjuvant Activity of PLA Microspheres Regulated by Protamine Sulfate

采用快速膜乳化法,以聚乳酸(PLA)为材料,分别以乙酸乙酯和二氯甲烷为有机溶剂,制备了粒径400和900nm的均一PLA微球和鱼精蛋白(PS)修饰的PLA-PS微球,以微球为佐剂、HBsAg为抗原免疫小鼠,在动物水平上研究其免疫调控作用,考察了不同粒径微球对抗原体内免疫效果的影响.结果表明,鱼精蛋白修饰后的PLA微球对乙肝表面抗原的吸附率增加,未修饰的PLA微球对抗原的吸附率仅为2.07%,修饰后吸附率为8.16%;修饰后微球为佐剂的免疫效果优于未修饰微球为佐剂的免疫效果,鱼精蛋白修饰能显著提升小鼠脾细胞分泌Th1型细胞因子(IL-2和IFN-γ)数(分别提升了261%和139%),分泌Th2型细胞因子IL-4数增加了67%;用修饰后平均粒径400 nm微球为佐剂免疫小鼠,IL-2分泌水平是900nm微球为佐剂的1.68倍.

Polylactic acid （PLA） microspheres and protamine sulfate （PS） modified PLA microspheres were prepared with ethyl acetate （for 400 nm diameter） or dichloromethane （for 900 nm diameter） by premix membrane emulsification method. BALB/c mice were used to evaluate the adjuvanticity of as-prepared microparticles for HBsAg, and the effect of particles size on their adjuvanticity was investigated. The results indicated that PS modification significantly promoted the adsorption of HBsAg onto the microspheres, and the adsorption rate was increased to 8.16% from 2.07%. Compared with PLA microspheres, PS modified microspheres induced more potent immune response, the spot formation cells （SFCs） of IL-2 and IFN-y （Th 1 type cytokine） were increased 261% and 139%, respectively. The SFCs of IL-4 secretion of Tb_2 type cytokine were also enhanced by 67%. Immune effect of different sizes of PLA-PS microspheres demonstrated that the secretion level of IL-2 for 400 nm microspheres was 1.68 times to the counterparts of 900 nm microspheres.