粉尘螨3类变应原的B细胞线性表位预测及鉴定

Prediction and identification of linear B-cell epitopes in major group 3 allergen derived from Dermatophagoides farina

目的预测并鉴定粉尘螨3类变应原(Der f 3)中的B细胞线性表位。方法运用生物信息学技术,从抗原性、表面易接近性、柔韧性、亲水性、β转角等5个方面在线预测Der f3的B细胞线性抗原表位。同时,采用人工合成法合成相应B细胞表位肽分别与由12份螨性过敏性哮喘患者血清组成的3个血清池共同作用,明确其中的强阳性表位肽序列。结果成功预测了Der f 3中的8个B细胞表位肽。其中,在过敏性患者血清与变应原特异性IgE结合试验中确认了33KAKAGDCP40、86HASGGEKIQVAEIYQHENYDSMTID110、118LKTPMTLDQTNAKPVPLPPQGSDVKVG144、199DVANGGVDSCQGDSGGPVVD218和156QEGSYSLP1635个强阳性表位肽序列。结论成功确认了Der f 3变应原中5个B细胞线性表位序列,为尘螨过敏性哮喘的诊断和治疗奠定基础。

Objective To predict and identify the linear B-cell epitopes in the major group 3 allergen derived from Derma-tophagoides farina（Der f 3）. Methods The linear B-cell epitopes of Der f 3 allergen were analyzed based on the physicochemi-cal properties of amino acids including antigenicity,surface accessibility,flexibility,hydrophilicity,beta-turn by online bioinfor-matics softwares. The eight predicted peptides of linear B-cell epitopes were artificially synthesized and incubated with three aller-gic serum pools（4 serum samples in each）,which were consisted of total 12 serum samples from the allergic individuals,and the strong positive epitopes were selected. Results Eight B-cell epitopes from Der f 3 were predicted successfully. Five of eight B-cell epitopes were identified with strong IgE-binding abilities followed by specific IgE assay. The amino acid sequences of them were following：33KAKAGDCP40, 86HASGGEKIQVAEIYQHENYDSMTID110, 118LKTPMTLDQTNAKPVPLPPQGSDVKVG144, 156QEGSYSLP163 and 199DVANGGVDSCQGDSGGPVVD218. Conclusions Five linear B-cell epitopes of Der f 3 allergen have been identified successfully. This result might provide a basis of the diagnosis and treatment for asthma.