Kossaczka Z, Szu S C
Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2720, USA.
Glycoconj J. 2000 Jun;17(6):425-33. doi: 10.1023/a:1007164216202.
Vibrio cholerae serotype O139 is a new etiologic agent of epidemic cholera. There is no vaccine available against cholera caused by this serotype. V. cholerae O139 is an encapsulated bacterium, and its polysaccharide capsule is an essential virulent factor and likely protective antigen. This study evaluated several synthetic schemes for preparation of conjugates of V. cholerae O139 capsular polysaccharide (CPS) with chicken serum albumin as the carrier protein (CSA) using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) or 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as activating agents. Four conjugates described here as representative of many experiments were synthesized in 2 steps: 1) preparation of adipic acid hydrazide derivative of CPS (CPS(AH)) or of CSA (CSA(AH)), and 2) binding of CPS(AH) to CSA or of CPS to CSA(AH). Although all conjugates induced CPS antibodies, the conjugate prepared by EDC-mediated binding of CPS and CSA(AH) (EDC:CPS-CSA(AH)) was statistically significantly less immunogenic than the other three conjugates. Representative sera from mice injected with these three conjugates contained antibodies that mediated the lysis of V. cholerae O139 inoculum. Evaluation of the different synthetic schemes and reaction conditions in relation to the immunogenicity of the resultant conjugates provided the basis for the preparation of a V. cholerae O139 conjugate vaccine with a medically useful carrier protein such as diphtheria toxin mutant.
霍乱弧菌O139血清型是流行性霍乱的一种新病原体。目前尚无针对该血清型霍乱的疫苗。霍乱弧菌O139是一种有荚膜的细菌，其多糖荚膜是一种重要的致病因子，可能也是保护性抗原。本研究评估了几种合成方案，以1-乙基-3-(3-二甲基氨基丙基)碳二亚胺（EDC）或1-氰基-4-二甲基氨基吡啶四氟硼酸盐（CDAP）作为活化剂，制备霍乱弧菌O139荚膜多糖（CPS）与鸡血清白蛋白（CSA）作为载体蛋白的偶联物。这里描述的作为众多实验代表的四种偶联物分两步合成：1）制备CPS的己二酸酰肼衍生物（CPS(AH)）或CSA的己二酸酰肼衍生物（CSA(AH)），以及2）将CPS(AH)与CSA结合或CPS与CSA(AH)结合。尽管所有偶联物都能诱导产生CPS抗体，但通过EDC介导的CPS与CSA(AH)结合制备的偶联物（EDC:CPS-CSA(AH)）在统计学上的免疫原性明显低于其他三种偶联物。注射这三种偶联物的小鼠的代表性血清中含有介导霍乱弧菌O139接种物裂解的抗体。评估不同的合成方案和反应条件与所得偶联物免疫原性的关系，为制备一种带有医学上有用载体蛋白（如白喉毒素突变体） 的霍乱弧菌O139偶联疫苗提供了依据。
