van der Put Robert M F, Kim Tae Hee, Guerreiro Catherine, Thouron Françoise, Hoogerhout Peter, Sansonetti Philippe J, Westdijk Janny, Stork Michiel, Phalipon Armelle, Mulard Laurence A
Institute for Translational Vaccinology (Intravacc) , P.O. Box 450, 3720 AL Bilthoven, The Netherlands.
Unité de Chimie des Biomolécules, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.
Bioconjug Chem. 2016 Apr 20;27(4):883-92. doi: 10.1021/acs.bioconjchem.5b00617. Epub 2016 Mar 21.
Conjugation chemistry is among the most important parameters governing the efficacy of glycoconjugate vaccines. High robustness is required to ensure high yields and batch to batch reproducibility. Herein, we have established a robust bioconjugation protocol based on the thiol-maleimide addition. Major variables were determined and acceptable margins were investigated for a synthetic pentadecasaccharide-tetanus toxoid conjugate, which is a promising vaccine candidate against Shigella flexneri serotype 2a infection. The optimized process is applicable to any thiol-equipped hapten and provides an efficient control of the hapten:carrier ratio. Moreover, comparison of four S. flexneri 2a glycoconjugates only differing by their pentadecasaccharide:tetanus toxoid ratio confirmed preliminary findings indicating that hapten loading is critical for immunogenicity with an optimal ratio here in the range of 17 ± 5. In addition, the powerful influence of alum on the immunogenicity of a Shigella synthetic carbohydrate-based conjugate vaccine candidate is demonstrated for the first time, with a strong anti-S. flexneri 2a antibody response sustained for more than one year.
共轭化学是影响糖共轭疫苗效力的最重要参数之一。需要高稳健性以确保高产量和批次间的可重复性。在此，我们基于硫醇-马来酰亚胺加成反应建立了一种稳健的生物共轭方案。对于一种有望用于预防福氏志贺菌2a型感染的合成十五糖-破伤风类毒素共轭物，我们确定了主要变量并研究了可接受范围。优化后的工艺适用于任何带有硫醇的半抗原，并能有效控制半抗原与载体的比例。此外，对四种仅十五糖与破伤风类毒素比例不同的福氏志贺菌2a型糖共轭物进行比较，证实了初步研究结果，即半抗原负载量对免疫原性至关重要，此处最佳比例在17±5范围内。此外，首次证明了明矾对一种基于志贺菌合成碳水化合物的共轭疫苗候选物免疫原性的强大影响，产生了持续一年多的强烈抗福氏志贺菌2a型抗体反应。
