【摘要】 目的构建粉尘螨1类变应原(Der f 1)的T和B细胞表位嵌合基因原核表达载体。方法将Der f 1包含的5个T细胞表位(T1~T5)和6个B细胞表位(B1~B6),以B1-T1-B2-T2-B3-T3-B4-T4-B5-T5-B6和B1-B2-B3-B4-B5-B6-T1-T2-T3-T4-T5连接方式直接合成表位嵌合基因,并分别命名为Der f 1A和Der f 1B。构建原核表达重组质粒pET-28a(+)-Der f 1A和pET-28a(+)-Der f 1B,双酶切及测序验证的阳性克隆转化到E.coli BL21(DE3)后诱导表达。SDS-PAGE分析表达产物后进行纯化,并进行Western blotting鉴定。ELISA法检测嵌合蛋白对粉尘螨过敏患者血清IgE抗体的结合力。结果双酶切及测序结果表明,成功构建了原核表达重组质粒pET-28a(+)-Der f 1A和pET-28a(+)-Der f 1B;SDS-PAGE分析表明,Der f 1A和Der f 1B诱导并纯化成功,Western blotting结果进一步证实纯化了Der f 1A和Der f 1B嵌合蛋白。与Der f 1相比,Der f 1A和Der f 1B嵌合蛋白与粉尘螨过敏患者血清IgE抗体的结合能力显著降低(P均<0.05),但Der f 1A和Der f 1B间差异无统计学意义(P>0.05)。结论成功表达了Der f 1的T和B细胞表位嵌合蛋白,为粉尘螨过敏的特异性免疫治疗奠定了基础。更多还原

【Abstract】 Objective To construct and express a chimeric gene with T-/B-cell epitopes of the major allergen group 1 from Dermatophagoides farina(Der f 1). Methods Two chimeric genes,Der f 1A and Der f 1B,were synthesized as B1-T1-B2-T2-B3-T3-B4-T4-B5-T5-B6 and B1-B2-B3-B4-B5-B6-T1-T2-T3-T4-T5 pattens. Two recombinant vectors,pET-28a(+)-Der f 1A and pET-28a(+)-Der f 1B,were constructed for prokaryotic expression. These chimeric genes were induced by 1 mmol/L IPTG (final concentration),digested with restriction enzymes and sequenced. The chimeric proteins were analyzed by SDS-PAGE and Western blotting. Results After digestion by restriction enzymes and sequencing,the recombinant vectors were constructed successfully. The specific bands for chimeric proteins were visible by SDS-PAGE and Western blotting,suggesting that these proteins were purified successfully. Further analyses were performed for IgE-binding properties of Der f 1A and Der f 1B to sera from patients sensitized to house dust mite. Compared with the parental allergens Der f 1,Der f 1A and Der f 1B had reduced IgE -binding capacity(both P < 0.05),whereas the difference between Der f 1A and Der f 1B was not statistically significant(P >0.05). Conclusion Two chimeric proteins are expressed successfully,which contain T-/B-cell epitopes of Der f 1 and provide a basis for specific immunotherapy.更多还原