Le Roy D, Crouzier C, Dho-Moulin M, Dumont A S, Bouchet A, Lafont J P, Andremont A
Laboratoire d'Ecologie microbienne, Institut Gustave-Roussy, Villejuif, France.
Res Microbiol. 1995 Feb;146(2):167-74. doi: 10.1016/0923-2508(96)80894-1.
Production of aerobactin has been reported to be a virulence factor in members of the family Enterobacteriaceae. To investigate the protection afforded by humoral immunity directed towards aerobactin in infectious diseases caused by aerobactin-producing strains, we tested the efficacy of mAbAERO1, a murine monoclonal antibody directed to ferric aerobactin, which, in vitro, was found to impair the growth of aerobactin-dependent strains of Enterobacteriaceae under iron-limited conditions. The mortality of mice experimentally infected with the aerobactin-producing strains Escherichia coli V2019 (LD50 = 3.5 x 10(5) CFU/mice) or Klebsiella pneumoniae Caroli (LD50 = 1.3 CFU/mice) was not reduced when 1 mg of mAbAERO1 was injected intravenously 1 h before or 1 h after bacterial challenge. Nor was mortality reduced after challenge with either E. coli V2019 or K. pneumoniae Caroli, even though the active immunization of mice with purified FeAero (ferric aerobactin) conjugated with thyroglobulin as followed by a rise in systemic anti-FeAero antibodies. Lastly, chicks born of hens immunized with FeAero showed evidence of antibody transmission towards FeAero, but were not protected when challenged with E. coli MT78, an aerobactin-producing strain highly virulent for chickens. Therefore, under the experimental conditions tested, humoral immunity against aerobactin appeared to play only a minor role in protection against infections caused by aerobactin-producing members of the family Enterobacteriaceae. However, other experimental models should be tested to confirm these observations.
据报道，气杆菌素的产生是肠杆菌科成员的一种毒力因子。为了研究针对气杆菌素的体液免疫在由产气体杆菌素菌株引起的传染病中所提供的保护作用，我们测试了mAbAERO1的疗效，mAbAERO1是一种针对铁载体气杆菌素的鼠单克隆抗体，在体外发现它在铁限制条件下会损害依赖气杆菌素的肠杆菌科菌株的生长。在用产气体杆菌素的菌株大肠杆菌V2019（半数致死量=3.5×10⁵CFU/小鼠）或肺炎克雷伯菌卡罗利亚种（半数致死量=1.3CFU/小鼠）进行实验性感染的小鼠中，在细菌攻击前1小时或攻击后1小时静脉注射1mg mAbAERO1，小鼠的死亡率并未降低。在用大肠杆菌V2019或肺炎克雷伯菌卡罗利亚种攻击后，死亡率也没有降低，尽管用与甲状腺球蛋白偶联的纯化铁载体气杆菌素对小鼠进行主动免疫后，全身抗铁载体气杆菌素抗体有所增加。最后，用铁载体气杆菌素免疫的母鸡所产的雏鸡显示出向铁载体气杆菌素传递抗体的证据，但在用对鸡具有高毒力的产气体杆菌素菌株大肠杆菌MT78攻击时并未受到保护。因此，在所测试的实验条件下，针对气杆菌素的体液免疫在抵抗由产气体杆菌素的肠杆菌科成员引起的感染的保护中似乎只起次要作用。然而，应该测试其他实验模型来证实这些观察结果。
