文献类型：期刊文献

中文题名：18C型肺炎球菌多糖不同O-乙酰基保留率与结合物免疫原性相关性研究

英文题名：Study on the correlation between the retention rate of different O-acetyl groups of 18C pneumococcal polysaccharides and the immunogenicity of conjugates

作者：张钰奇[1];房明[2];李献林[1];吕明钰[1];马凯凯[1];杜娇[1];杨英英[1];强鹏侠[1];罗树权[1];周海飞[1]

第一作者：张钰奇

机构：[1]兰州生物制品研究所有限责任公司第一研究室甘肃省疫苗技术创新中心,甘肃兰州730046;[2]甘肃中医药大学基础医学院,甘肃省高校重大疾病分子医学与中医药防治研究省级重点实验室,甘肃兰州730000

第一机构：兰州生物制品研究所有限责任公司第一研究室甘肃省疫苗技术创新中心,甘肃兰州730046

年份：2025

卷号：53

期号：2

起止页码：18

中文期刊名：微生物学免疫学进展

外文期刊名：Progress In Microbiology and Immunology

语种：中文

中文关键词：肺炎球菌;荚膜多糖;O-乙酰基;磷酸甘油;结合物;抗原性;免疫原性

外文关键词：Pneumococcus;Capsular polysaccharide;O-acetyl;Phosphate-glycerol;Conjugates;Antigenicity;Immunogenicity

摘要：目的旨在探讨O-乙酰基含量与18C型肺炎球菌多糖结合物免疫原性的相关性,为多价肺炎球菌结合疫苗中18C型中间品制备过程中多糖O-乙酰基含量的质量控制提供依据和参数。方法分别用三氟乙酸、乙酸、过氧化氢、氢氧化钠对18C型荚膜多糖进行降解。通过优化反应条件,获得分子大小相对一致,去除、部分去除以及基本保留O-乙酰基的多糖降解物和去除磷酸甘油基团的多糖降解物。不同O-乙酰基含量的多糖降解物与破伤风类毒素衍生物结合制备成多糖蛋白质结合物。结合物纯化后采用0.2μg/剂免疫小鼠,进行抗原性、免疫原性研究。结果制备分子大小相对一致,O-乙酰基保留率分别为2.80%、67.00%、100.00%的多糖降解物。由以上3批多糖降解物制备的结合物多糖蛋白质比值在0.48~0.58,结合物分子大小处于同一水平。经抗原性检测:①基本保留O-乙酰基的多糖降解物抗原性与原料多糖基本一致;②去除O-乙酰基的多糖降解物抗原性损失严重;③部分去除O-乙酰基的多糖降解物抗原性与原料多糖相比存在差异;④去除磷酸甘油的多糖降解物基本丧失抗原性;⑤制备的结合物中:仅去除O-乙酰基的多糖结合物与原料多糖有明显差别,其他2组与原料多糖均无明显差别。小鼠血清IgG结果表明,3组不同O-乙酰基保留率的结合物抗多糖IgG差异无统计学意义(P=0.059,P>0.05),组间GMU最大值与最小值的比值为3.20;OPA抗体滴度的结果显示,3组不同O-乙酰基保留率的结合物OPA抗体滴度差异无统计学意义(P=0.104,P>0.05),组间GMT最大值与最小值的比值为8.10。结论不同O-乙酰基保留率与18C型肺炎球菌多糖降解物及结合物的抗原性密切相关,与结合物免疫原性的关系仍不十分明确,初步建议在18C型肺炎球菌多糖结合疫苗的工艺研发中保留O-乙酰基并重点关注特异基团含量。
Objective This study aims to investigate the correlation between O-acetyl group content and the immunogenicity of 18C pneumococcal polysaccharide conjugate,providing a basis and parameters for quality control of O-acetyl group content in serotype 18C polysaccharides during the preparation of intermediates for the multivalent pneumococcal conjugate vaccines.Methods The 18C polysaccharides was degraded using trifluoroacetic acid,acetic acid,hydrogen peroxide,and sodium hydroxide.By optimizing the reaction conditions,polysac-charide degradations with relatively uniform molecular sizes were obtained,including polysaccharides with removal,partial removal,and basically retention of the O-acetyl group.The polysaccharide degradations with different O-acetyl content were combined with tetanus toxoid derivatives to prepare polysaccharide conjugates.After purification,the conjugates were administered to mice at 0.2μg per dose for antigenicity and immunogenicity studies.Results Polysaccharide degradations with relatively uniform molecular size and O-acetyl retention of 2.80%,67.00%and 100.00%were prepared.The polysaccharide-protein ratio of the conjugates prepared from these three batches of polysaccharide degradation products ranges from 0.48 to 0.58,and the molecular sizes of the conjugates were at the same level.Antigenicity test:①The antigenicity of the polysaccharide degradation products with O-acetyl groups retained is basically consistent with that of the 18C polysaccharide.②Polysaccharide degradations with fully removed O-acetyl groups had a serious loss of antigenicity.③Polysaccharide degradations with partially removed O-acetyl groups show differences in antigenicity compared to the 18C polysaccharide.④Removal of phosphate-glycerol results in loss of antigenicity of polysaccharide degradations.⑤Among the prepared polysaccharide-protein conjugates:only the polysaccharide conjugate with fully removed O-acetyl groups demonstrate significant differences in antigenicity from the 18C polysaccharide,while the other two groups were not significantly different from the 18C polysaccharide.The results of mouse serum IgG levels demonstrated no statistically significant differences in anti-polysaccharide IgG among the three conjugate groups with varying O-acetyl retention rates(P=0.059,P>0.05),with a maximum-to-minimum GMU ratio of 3.20 across groups.Similarly,OPA antibody titers showed no statistically significant intergroup differences(P=0.104,P>0.05)among the three O-acetyl retention rate variants,exhibiting a maximum-to-minimum GMT ratio of 8.10.Conclusion The O-acetyl group retention rates is closely related to the antigenicity of 18C pneumococcal polysaccharide degradations and conjugates while the relationship with the immunogenicity of the conjugates remains unclear.It is initially recommended to retain the O-acetyl groups and focus on the content of the specific groups in the process of development type 18C pneumococcal conjugate vaccines.