嗜水气单胞菌ZN1株Mah-TrxA融合蛋白的粘附功能分析

Biological Functions of Mah-TrxA Fusion Protein from Aeromonas hydrophila

为深入探讨嗜水气单胞菌(Aeromonas hydrophila,Ah)主要粘附素在菌体侵入宿主和介导宿主产生免疫过程可能扮演的角色,对Ah菌ZN1株主要粘附素重组基因的表达产物的部分生物学功能进行分析。通过酶联免疫吸附试验、细胞与Ah菌的粘附试验及粘附抑制和阻断试验,研究分析克隆表达的Mah-TrxA(硫氧还蛋白与主要粘附素形成的融合蛋白)生物学功能。结果显示:克隆表达的Mah-TrxA融合蛋白具有良好的抗原性和免疫原性,对不同Ah菌株有交叉粘附抑制的作用,抗原竞争性抑制试验和抗体阻断试验均能显著减少不同Ah菌株对EPC的粘附作用。因此,克隆表达的Mah-TrxA确为ZN1菌株的主要粘附素;基因工程技术以融合蛋白形式表达的Mah-TrxA与野生菌株ZN1表达的主要粘附素具有类似的生物学活性。

This experimentation was designed to help understand the antigenic and immunogenic rules of Aeromonas hydrophila （Ah）. Indirect enzyme-linked immunosorbent assay showed the ratios of the antibody titers of the rabbit anti--ZNl-outer membrane protein （OMP） serum to the expression product, Mah-TrxA, and the recombinant protein of thioredoxin and a major adhesion agent and ZN1-OMP to be 1 ： 3 200 and 1 ： 12 800, respectively; and the ratios of the antibody titers of the rabbit anti- Mah-TrxA serum to Mah-TrxA and ZN1-OMP to be 1：12 800 and 1： 1 600, respectively. Carp epithelial tumor cells （EPC） were used to study the adhesion effect of different sources and serotypes of Ah to EPC, as well as the biological functions played by Mah-TrxA. The adhesion test indicated that Ah were separated from the fish, the serotypes were O ： Ahl0501, O ： 9, and O ： CQ-1 the adhesion rate of Ah to EPC was greater than 97% ATCC7966 was separated from milk, the serotype was O ： 1; and, the adhesion rate of ATCC7966 to EPC was 78.5%. The results indicated that Mah-TrxA and the rabbit anti- Mah-TrxA serum could significantly inhibit or block the bacterial adhesion to EPC. It suggested that the fusion protein expressed through genetic engineering techniques in Ah had similar antigenicity and immunogenicity as the wild strain, ZN1.