National Center for Lot Release, National Institute of Food & Drug Safety Evaluation, Korea Food & Drug Administration, Republic of Korea.
Vaccine. 2013 Jun 24;31(29):2988-93. doi: 10.1016/j.vaccine.2013.04.060. Epub 2013 May 9.
Pertussis toxin (PTx) is an essential component of the acellular pertussis (aP) vaccine. However, because PTx in its native form is considered too toxic for human vaccine use, it must be inactivated into a stable, nontoxic form by treatment with chemical detoxifying agents or by genetic modification. Therefore, testing for the residual PTx in the aP vaccine is a major quality control step for vaccine manufacturers and regulatory authorities. The histamine sensitization test is currently the standard safety test method for all aP vaccines, regardless of the vaccine formula or the detoxification process, except for those with genetically modified PTx. However, test result variability and ethical concerns regarding animal use necessitate an alternative method. In vitro assays based on the biochemical properties of PTx have been considered as potential alternatives to the histamine sensitization test. In this study, the suitability of assays based on the ADP-ribosyltransferase and carbohydrate binding activities of PTx was assessed for PTx after treatment with formaldehyde, glutaraldehyde or both denaturants in sequence. The results indicated a distinctive pattern of the biochemical activities depending on the detoxification methods and storage conditions. These results suggest that although a more careful study is needed, these in vitro biochemical assays can be considered potential alternatives to the histamine sensitization test, as they might provide more specific safety information of aP vaccines.
百日咳毒素（PTx）是无细胞百日咳（aP）疫苗的重要组成部分。然而，由于 PTx 本身的形式被认为对人体疫苗使用过于有毒，因此必须通过用化学解毒剂处理或通过遗传修饰将其失活成稳定的、无毒的形式。因此，检测 aP 疫苗中残留的 PTx 是疫苗制造商和监管机构的主要质量控制步骤。尽管疫苗配方或解毒过程不同，但除了具有遗传修饰的 PTx 疫苗外，组胺致敏试验目前是所有 aP 疫苗的标准安全试验方法。然而，测试结果的可变性和动物使用的伦理问题需要替代方法。基于 PTx 生化特性的体外检测已被认为是替代组胺致敏试验的潜在方法。在这项研究中，评估了基于甲醛、戊二醛或两种变性剂顺序处理后 PTx 的 ADP-核糖基转移酶和碳水化合物结合活性的检测方法的适用性。结果表明，根据解毒方法和储存条件，生化活性呈现出独特的模式。这些结果表明，尽管需要更仔细的研究，但这些体外生化检测可以被认为是替代组胺致敏试验的潜在方法，因为它们可能提供更具体的 aP 疫苗安全性信息。
