Site-specific mutation and immunogenicity of Mannheimia varigena TbpB
10.16303/j.cnki.1005-4545.2025.05.10
- VernacularTitle:1株多源曼氏杆菌TbpB定点突变与免疫原性
- Author:
Zhihao YAN
1
;
Yuhong ZHU
1
;
Jian SHI
1
;
Xingyi MA
1
;
Ling GAN
1
;
Jianhua GUO
1
Author Information
1. 西南大学动物医学学院,重庆 402460
- Publication Type:Journal Article
- Keywords:
Mannheimia varigena;
transferrin binding protein B;
bovine transferrin;
site-specific mutation;
immunogenicity
- From:
Chinese Journal of Veterinary Science
2025;45(5):954-962
- CountryChina
- Language:Chinese
-
Abstract:
Mannheimia varigena(M.varigena)is a significant pathogen causing bovine respiratory disease.Transferrin binding protein B(TbpB)is a lipoprotein directly exposed to the outer mem-brane of the cell,which is not only involved in the bacterial iron metabolism pathway,but also an important virulence factor.This study aims to lay the groundwork for developing novel subunit vaccines by conducting site-directed mutagenesis on M.varigena TbpB binding-related residues and evaluating their immunogenicity.Based on whole-genome sequencing of a bovine M.varigena i-solate,its iron uptake pathway was predicted.Key amino acid residues of M.varigena TbpB that play a role for binding to bovine transferrin(bTf)was identified by bioinformatics.We constructed two M.varigena TbpB mutants(Y205A and Y258A)and assessed their bTf binding activity and immunogenicity through dot blot assays and mouse immunization studies.Dot blot assays result showed that the Y258A mutation caused TbpB to lose its ability to bind to bTf.Mouse immuniza-tion studies showed that,compared to wild-type TbpB,the mutants of TbpB induced higher levels of specific antibodies.In challenge experiments,mice immunized with mutant TbpB exhibited high-er survival rates.These results demonstrate that site-directed mutagenesis can enhance the immu-nogenicity of TbpB.This study provides a novel approach for developing new subunit vaccines a-gainst M.varigena.
