Key Laboratory of Biological Resources and Ecological Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
Chengdu Antegen Biotech Co., Ltd., Chengdu, 610041, China.
Curr Med Sci. 2023 Feb;43(1):22-34. doi: 10.1007/s11596-022-2652-y. Epub 2023 Jan 21.
This study aimed to describe, optimize and evaluate a method for preparing multivalent conjugate vaccines by simultaneous conjugation of two different bacterial capsular polysaccharides (CPs) with tetanus toxoid (TT) as bivalent conjugates.
Different molecular weights (MWs) of polysaccharides, activating agents and capsular polysaccharide/protein (CP/Pro) ratio that may influence conjugation and immunogenicity were investigated and optimized to prepare the bivalent conjugate bulk. Using the described method and optimized parameters, a 20-valent pneumococcal conjugate vaccine and a bivalent meningococcal vaccine were developed and their effectiveness was compared to that of corresponding licensed vaccines in rabbit or mouse models.
The immunogenicity test revealed that polysaccharides with lower MWs were better for Pn1-TT-Pn3 and MenA-TT-MenC, while higher MWs were superior for Pn4-TT-Pn14, Pn6A-TT-Pn6B, Pn7F-TT-Pn23F and Pn8-TT-Pn11A. For activating polysaccharides, 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) was superior to cyanogen bromide (CNBr), but for Pn1, Pn3 and MenC, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDAC) was the most suitable option. For Pn6A-TT-Pn6B and Pn8-TT-Pn11A, rabbits immunized with bivalent conjugates with lower CP/Pro ratios showed significantly stronger CP-specific antibody responses, while for Pn4-TT-Pn14, higher CP/Pro ratio was better. Instead of interfering with the respective immunological activity, our bivalent conjugates usually induced higher IgG titers than their monovalent counterparts.
The result indicated that the described conjugation technique was feasible and efficacious to prepare glycoconjugate vaccines, laying a solid foundation for developing extended-valent multivalent or combined conjugate vaccines without potentially decreased immune function.
本研究旨在描述、优化和评估一种通过同时将两种不同细菌荚膜多糖（CPs）与破伤风类毒素（TT）偶联制备双价结合疫苗的方法。
研究了不同分子量（MWs）的多糖、活化剂和荚膜多糖/蛋白（CP/Pro）比例对结合和免疫原性的影响，并进行了优化，以制备双价结合物粗品。使用所描述的方法和优化的参数，开发了 20 价肺炎球菌结合疫苗和双价脑膜炎球菌疫苗，并在兔或鼠模型中比较了它们的有效性与相应许可疫苗的比较。
免疫原性试验表明，MWs 较低的多糖更有利于 Pn1-TT-Pn3 和 MenA-TT-MenC，而 MWs 较高的多糖更有利于 Pn4-TT-Pn14、Pn6A-TT-Pn6B、Pn7F-TT-Pn23F 和 Pn8-TT-Pn11A。对于活化多糖，1-氰基-4-二甲氨基吡啶四氟硼酸盐（CDAP）优于溴化氰（CNBr），但对于 Pn1、Pn3 和 MenC，N-（3-二甲氨基丙基）-N'-乙基碳二亚胺盐酸盐（EDAC）是最合适的选择。对于 Pn6A-TT-Pn6B 和 Pn8-TT-Pn11A，用较低 CP/Pro 比的双价结合物免疫的兔子表现出明显更强的 CP 特异性抗体反应，而对于 Pn4-TT-Pn14，更高的 CP/Pro 比更好。我们的双价结合物并没有干扰各自的免疫活性，反而通常诱导出比单价对照物更高的 IgG 滴度。
结果表明，所描述的结合技术是可行和有效的，可用于制备糖结合疫苗，为开发免疫功能不减低的扩展价多价或联合结合疫苗奠定了坚实的基础。
