Identification of a Campylobacter jejuni protein that cross-reacts with cholera toxin
Identification of a Campylobacter jejuni protein that cross-reacts with cholera toxin
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DOI：
10.1128/iai.00139-07
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发表时间：
2007-06-01
影响因子：
3.1
通讯作者：
Adler, Ben
中科院分区：
文献类型：
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作者：
Albert, M. John;Haridas, Shilpa;Adler, Ben
空肠弯曲杆菌是否产生霍乱毒素样毒素（CTLT）的问题一直存在争议。本研究的目的是确定与空肠弯曲菌 CT 交叉反应的因子。通过中国仓鼠卵巢 (CHO) 细胞伸长测定法测试了在四种不同液体培养基中生长的空肠弯曲菌的滤液，据报道可促进 CTLT 产生，并使用 GM1 神经节苷脂酶联免疫吸附测定 (ELISA) 和免疫印迹法测试与 CT 抗体的反应性。通过基质辅助激光解吸电离飞行时间（MALDI TOF-TOF）测定蛋白质序列。据报道，来自 7 种参考菌株和 80 种临床菌株的滤液在 CHO 细胞测定中呈阴性，但来自 3 种参考菌株和 16 种临床菌株的滤液在 GM1 ELISA 中呈阳性。所有测试的菌株，包括不含 CT 基因同源物的空肠弯曲菌 NCTC 11168，都具有 53-kDa 的蛋白质，通过免疫印迹可与 CT 抗体发生反应。该条带被鉴定为空肠弯曲菌的主要外膜蛋白 PorA。通过免疫印迹，CT抗体与重组PorA反应，但重组PorA的抗体不与CT反应。我们的结果表明，空肠弯曲菌不产生功能性CTLT，但PorA与CT抗体的反应性会导致空肠弯曲菌产生功能性CTLT的错误结论。
The question of whether Campylobacter jejuni produces a cholera toxin-like toxin (CTLT) has been controversial. The objective of this study was to identify the factor that cross-reacts with CT from C.jejuni. Filtrates of C. jejuni grown in four different liquid media reported to promote CTLT production were tested by Chinese hamster ovary (CHO) cell elongation assay and for reactivity with CT antibody using GM1 ganglioside enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Protein sequence was determined by matrix-assisted laser desorption ionization-time of flight (MALDI TOF-TOF). Filtrates from seven reference strains reported to produce CTLT and from 80 clinical strains were negative in the CHO cell assay, but those from three reference strains and 16 clinical strains were positive by GM1 ELISA. All strains tested, including C.jejuni NCTC 11168, which does not contain a CT gene homologue, possessed a 53-kDa protein which reacted with CT antibody by immunoblotting. This band was identified as the major outer membrane protein, PorA, of C.jejuni. CT antibody reacted by immunoblotting with a recombinant PorA, but antibody to the recombinant PorA did not react with CT. Our results indicate that C. jejuni does not produce a functional CTLT, but the reactivity of PorA with CT antibody would lead to the erroneous conclusion that C. jejuni produces a functional CTLT.