Meningococcal Factor H Binding Protein Vaccine Antigens with Increased Thermal Stability and Decreased Binding of Human Factor H.
Meningococcal Factor H Binding Protein Vaccine Antigens with Increased Thermal Stability and Decreased Binding of Human Factor H.
复制标题
脑膜炎球菌 H 因子结合蛋白疫苗抗原具有增加的热稳定性和减少的人 H 因子结合。
DOI：
10.1128/iai.01491-15
复制
发表时间：
2016
影响因子：
3.1
通讯作者：
Beernink,PeterT
中科院分区：
文献类型：
--
作者：
Rossi,Raffaella;Konar,Monica;Beernink,PeterT
Neisseria meningitidis causes cases of bacterial meningitis and sepsis. Factor H binding protein (FHbp) is a component of two licensed meningococcal serogroup B vaccines. FHbp recruits the complement regulator factor H (FH) to the bacterial surface, which inhibits the complement alternative pathway and promotes immune evasion. Binding of human FH impairs the protective antibody responses to FHbp, and mutation of FHbp to decrease binding of FH can increase the protective responses. In a previous study, we identified two amino acid substitutions in FHbp variant group 2 that increased its thermal stability by 21°C and stabilized epitopes recognized by protective monoclonal antibodies (MAbs). Our hypothesis was that combining substitutions to increase stability and decrease FH binding would increase protective antibody responses in the presence of human FH. In the present study, we generated four new FHbp single mutants that decreased FH binding and retained binding of anti-FHbp MAbs and immunogenicity in wild-type mice. From these mutants, we selected two, K219N and G220S, to combine with the stabilized double-mutant FHbp antigen. The two triple mutants decreased FH binding >200-fold, increased the thermal stability of the N-terminal domain by 21°C, and bound better to an anti-FHbp MAb than the wild-type FHbp. In human-FH-transgenic mice, the FHbp triple mutants elicited 8- to 15-fold-higher protective antibody responses than the wild-type FHbp antigen. Collectively, the data suggest that mutations to eliminate binding of human FH and to promote conformational stability act synergistically to optimize FHbp immunogenicity.
