Pollack M, Prescott R K
J Infect Dis. 1982 May;145(5):688-98. doi: 10.1093/infdis/145.2.688.
Toxoid was prepared by treating exotoxin A of Pseudomonas aeruginosa with formalin. Coincubation of exotoxin A for two to four weeks at 37 degrees C with 0.5% formalin and 10(-3) M lysine followed by one to two weeks of storage in the absence of these reagents reduced cytotoxicity, preserved antigenicity, and minimized subsequent reversion of the toxoid. Formalin enhanced the adenosine diphosphate (ADP)-ribosyl transferase activity of the toxin while decreasing its toxicity, whereas formalin plus lysine reduced both. Although no antigenic changes were detected by immunodiffusion analysis, analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed minor alterations in the toxin structure. Toxoid induced high titers of antibody to exotoxin A in the sera of mice and rabbits. Antiserum to toxoid neutralized mouse lethality, cytotoxicity, and ADP-ribosyl transferase activity of untreated exotoxin A. Toxoid-immunized mice were resistant to large doses of exotoxin A administered iv.
类毒素是通过用福尔马林处理铜绿假单胞菌的外毒素A制备的。将外毒素A与0.5%福尔马林和10⁻³ M赖氨酸在37℃下共孵育两到四周，然后在没有这些试剂的情况下储存一到两周，可降低细胞毒性，保留抗原性，并使类毒素随后的回复突变最小化。福尔马林增强了毒素的二磷酸腺苷（ADP）-核糖基转移酶活性，同时降低了其毒性，而福尔马林加赖氨酸则两者都降低。虽然免疫扩散分析未检测到抗原性变化，但十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析显示毒素结构有微小改变。类毒素在小鼠和兔子血清中诱导产生高滴度的抗外毒素A抗体。类毒素抗血清中和了未处理的外毒素A的小鼠致死性、细胞毒性及ADP-核糖基转移酶活性。经类毒素免疫的小鼠对静脉注射大剂量的外毒素A具有抗性。
