Preparation and preclinical evaluation of two novel Staphylococcus aureus capsular polysaccharide 5 and 8-fusion protein (Hla-MntC-SACOL0723) immunoconjugates
Preparation and preclinical evaluation of two novel Staphylococcus aureus capsular polysaccharide 5 and 8-fusion protein (Hla-MntC-SACOL0723) immunoconjugates
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DOI：
10.1002/iub.2159
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发表时间：
2019-10-01
期刊：
影响因子：
4.6
通讯作者：
Mahdavi, Mehdi
中科院分区：
文献类型：
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作者：
Ahmadi, Khadijeh;Aslani, Mohammad M.;Mahdavi, Mehdi
金黄色葡萄球菌是医院和社区最常见的病原体之一。金黄色葡萄球菌广谱抗生素耐药性的出现使得治疗过程变得更加困难。因此，显然，针对病原体的有效预防策略可以显着降低医院护理相关的成本。在本报告中，我们描述了一种将来自金黄色葡萄球菌 Reynolds 菌株的金黄色葡萄球菌荚膜多糖 5 (CP5) 和来自金黄色葡萄球菌 Becker 菌株的 8 (CP8) 与融合蛋白 (Hla-MntC-SACOL0723) 结合的简单方法，并研究了其生物活性。通过使用 ADH（作为桥）和 EDAC（作为偶联剂）完成缀合。通过常规多糖/蛋白质含量测定，然后进行反相色谱和 FTIR 光谱来表征免疫缀合物。各组小鼠分别用结合疫苗、荚膜多糖和磷酸盐缓冲盐水（PBS）免疫作为对照组。通过 ELISA、调理吞噬试验和攻击研究中细菌负荷的测定来评估候选疫苗的功能活性。结果表明，针对缀合分子产生的特异性抗体（总IgG）滴度高于非缀合荚膜多糖。结合疫苗抗血清的调理活性显着高于单独的多糖（细菌数量减少 58%，而 1:2 稀释时细菌数量减少 16.3%，p < .05）。此外，与 PBS 和非结合对照相比，在用金黄色葡萄球菌 COL 菌株细胞攻击后，结合疫苗组的细菌负荷显着减少。总之，免疫缀合物可以开发为针对金黄色葡萄球菌的潜在候选疫苗。
Staphylococcus aureus is one of the most common pathogens in the hospital and the community. The emergence of broad-spectrum antibiotic resistance in S. aureus has made the treatment process more difficult. Therefore, it is obvious that an effective prevention strategy against the pathogen could significantly reduce costs related to care in hospitals. In this report, we describe a simple approach to conjugate S. aureus capsular polysaccharide 5 (CP5) from S. aureus Reynolds strain and 8 (CP8) from S. aureus Becker strain to a fusion protein (Hla-MntC-SACOL0723) and investigation of its bioactivity. The conjugation was done by using ADH (as a bridge) and EDAC (as a coupling agent). The immunoconjugates were characterized by routine polysaccharide/protein contents assays followed by reverse phase chromatography and FTIR spectroscopy. The groups of mice were immunized with conjugate vaccines, capsular polysaccharides, and phosphate-buffered saline (PBS) as a control group. The functional activity of the vaccine candidates was evaluated by ELISA, opsonophagocytosis tests, and determination of bacterial load in challenge study. The results showed that the specific antibody (total IgG) titers raised against conjugate molecules were higher than those of the nonconjugated capsular polysaccharides. The opsonic activity of the conjugate vaccines antisera was significantly higher than polysaccharides alone (58% reduction in the number of bacteria versus 16.3% at 1:2 dilution, p < .05), Further, the conjugate vaccine group had a significant reduction in bacterial load after challenge with S. aureus COL strain cells as compared to the PBS and nonconjugated controls. In conclusion, the immunoconjugates could be developed as a potential vaccine candidate against S. aureus.