Zhu W.-H.,Beijing Zhifei Luzhu Biopharmaceutical Co. |
Zong X.-K.,Beijing Zhifei Luzhu Biopharmaceutical Co. |
Hu X.-H.,Beijing Zhifei Luzhu Biopharmaceutical Co. |
Hu Y.-F.,Beijing Zhifei Luzhu Biopharmaceutical Co. |
Du L.,Beijing Zhifei Luzhu Biopharmaceutical Co.
Chinese Journal of Biologicals | Year: 2015
Objective: To prepare the O-specific polysaccharide-protein conjugate of Shigella flexneri 2a and determine its immunogenicity. Methods: O-specific polysaccharide was hydrolyzed and derivatived with adipic acid dihydrazide (ADH) in mediation of l-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride(EDAC), and the prepared derivative was conjugated to tetanus toxoid (IT). The obtained conjugate was tested for biochemical indexes. Mice were immunized with polysaccharide and the conjugates prepared by the method in this study as well as those by cyan activation method and by ammonia reduction method for 3 times, 0.2 ml (containing 2 μg polysaccharide) for each, and determined for serum antibody titer 2 weeks after each immunization, based on which the genomic mean titer (GMT) was calculated. Results: Both the free polysaccharide and protein content in conjugates were low, while the endotoxin content met the relevant requirements. The KD value of polysaccharide was 0.85, while that of conjugate increased to 0.02. All the conjugates induced specific antibody in mice. The GMTs of antibody induced by various conjugates showed no significant difference (each P > 0.05), which increased significantly with increasing doses (each P < 0.05). Conclusion: The prepared O-specific polysaccharide-protein conjugate of Shigella flexneri 2a showed good immunogenicity. The method for preparation was simple, and the reaction condition was moderate, which were suitable for large-scale production.