P277多肽融合热休克蛋白65提高抗1型糖尿病的作用

为了提高P277肽抗1型糖尿病的作用, 把P277肽融合在卡介苗热休克蛋白65的C端, 构建了pET28a- HSP65-P277高效表达载体, 在大肠杆菌中高效可溶性表达。利用硫酸铵分级沉淀、阴离子交换柱层析分离纯化了融合蛋白HSP65-P277。使用HSP65-P277在没有任何佐剂存在的情况下免疫非肥胖性糖尿病(NOD)小鼠, 通过三次腹腔注射, 每月收集被免疫动物的血清, 血糖浓度用自动生化分析仪测定。结果显示HSP65-P277免疫组小鼠血糖平均值及糖尿病的累积发病率和其余组相比均有显著差异(P<0.01), 融合蛋白HSP65-P277抗NOD小鼠糖尿病的作用显著高于单独的P277和HSP65。为进一步开发能用于临床的1型糖尿病疫苗提供了良好的设计思路, HSP65-P277极有可能进一步发展成为新的抗I型糖尿病的疫苗。

Improved Efficacy of P277 Fused to Heat Shock Protein 65 of Mycobacterium tuberculosis Against Diabetes in Nonobese Diabetic Mice

To improve the efficacy of peptide P277 in preventing autoimmune diabetes, heat shock protein 65 kD (HSP65) of Mybobacterium tuberculosis var. bovis was fused with linear polypeptide epitope of P277 and expressed as soluble protein in Escherichia coli. The fusion protein HSP65-P277 was purified by anion exchange column chromatography and then used to immunize prediabetic NOD mice with three ip inoculations in absence of adjuvants. Serum samples from the immunized mice were collected monthly and the concentration of blood glucose was measured. The study showed that administration of HSP65-P277 to NOD mice could prevent the development of diabetes more efficiently than the peptide P277 itself or HSP65. Fused to heat shock protein 65 of Mycobacterium tuberculosis could improve the efficacy of diabetes prevention of P277 in nonobese diabetic mice. The results suggest the fusion protein of HSP65-P277 would be useful for treating insulin-dependent diabetes mellitus.