Original Article
Immunogenicity comparison of type 4 pneumococcal polysaccharide-diphtheria toxoid conjugates prepared by different methods
Xiaoqi Nie, Xin Li, Tao Ren, Xiuli Tang, Jing Ti, Zhaohui Yang
Published 2019-04-10
Cite as Int J Biologicals, 2019, 42(2): 53-56. DOI: 10.3760/cma.j.issn.1673-4211.2019.02.001
Abstract
ObjectiveTo compare the immunogenicity of type 4 pneumococcal polysaccharide (PS4)-diphtheria toxoid(DT) conjugates (PS4-DT) prepared with 1-cyano-4-dimethylaminopyridine tetrafluoroborate (CDAP) and cyanogen bromide (CNBr) as activators.
MethodsOne batch each of PS4-DT bulk was prepared with CDAP or CNBr as activator, and the relevant quality indexes of 2 PS4-DT bulks were detected. NIH mice were injected subcutaneously 3 times with either of PS4-DT bulks every 2 weeks. The mice sera were collected 1 week after the last immunization. The serum antibody titers were detected by inhibition ELISA, and the immunogenicities of PS4-DT bulks prepared by different methods were compared.
ResultsThe main quality indexes of both PS4-DT bulks met relevant requirement standards, and the conjugated PS4 contents in PS4-DT bulks were 257.1 and 203.0 μg/ml, respectively. Both PS4-DT bulks specifically reacted with PS4 anti-sera. The inhibition ELISA showed that the inhibition rates of both PS4-DT bulks for PS4 anti-sera reached 100%. The anti-PS4 levels induced by mice immunized with 2 PS4-DT bulks were similar, and antibody geometric mean titers were 970.06 and 844.49, respectively.
ConclusionThe immunogenicities of PS4-DT bulks prepared by two different methods are similar in mice, and both can induce high antibody levels in immunized mice.
Key words:
Streptococcus pneumoniae; Polysaccharides, bacterial; Diphtheria toxoid
Contributor Information
Xiaoqi Nie
R &
D Center, Beijing Minhai Biotechnology Co., Ltd., Beijing 102600, China
Xin Li
Tao Ren
Xiuli Tang
Jing Ti
Zhaohui Yang