Oloomi Mana, Bouzari Saeid
Molecular Biology Unit, Pasteur Institute of Iran, Tehran, Iran.
Iran J Allergy Asthma Immunol. 2011 Mar;10(1):41-6.
Shiga toxin (Stx) is the principal virulence factor of Shigatoxigenic Escherichia coli (STEC), a food-born pathogen associated disease with uncomplicated diarrhea or the hemolytic-uremic syndrome. In this study, rabbit polyclonal anti recombinant A, B subunits of Shiga toxin and holotoxin antisera were raised and employed for immunological purpose. By immunoblotting, these antisera recognized respective subunit and the holotoxin antiserum recognized both subunits, equally. The raised antisera could also neutralize the cytotoxicity of the shiga toxin on vero cells. The neutralizing ability of the prepared sera was compared for different subunits. The neutralization of toxicity was observed by incubation of raised sera with the rStx or Shiga toxin from wild type strains. The inhibition of cell toxicity was shown by anti-A, anit-B and anti-AB antisera, separately. It was shown that anti-A antibody, more significantly recognized Stx producing strains, comparing to anti-B antibody. These sera from immunized rabbits were also used as specific antibodies in Enzyme-Linked Immunosorbant Assay (ELISA) for detection of Shiga toxin. It was demonstrated that the raised antibodies especially antibody against A subunit could be a useful tool for immunological diagnosis of STEC induced infection.
志贺毒素（Stx）是产志贺毒素大肠杆菌（STEC）的主要毒力因子，STEC是一种与单纯性腹泻或溶血尿毒综合征相关的食源性病原体。在本研究中，制备了兔抗重组志贺毒素A、B亚基的多克隆抗体以及抗全毒素抗血清，并将其用于免疫学目的。通过免疫印迹法，这些抗血清识别各自的亚基，并且全毒素抗血清能同等程度地识别两个亚基。所制备的抗血清还能中和志贺毒素对vero细胞的细胞毒性。比较了所制备血清对不同亚基的中和能力。通过将所制备的血清与重组Stx或野生型菌株的志贺毒素一起孵育来观察毒性的中和情况。抗A、抗B和抗AB抗血清分别显示出对细胞毒性的抑制作用。结果表明，与抗B抗体相比，抗A抗体更能显著识别产Stx的菌株。这些来自免疫兔的血清还被用作酶联免疫吸附测定（ELISA）中的特异性抗体来检测志贺毒素。结果表明，所制备的抗体，尤其是抗A亚基的抗体，可能是用于STEC诱导感染的免疫学诊断的有用工具。
