Immunogenicity of Rv2318 and its epitope peptides of Mycobacterium tuberculosis
10.3969/j.issn.1002-2694.2025.00.165
- VernacularTitle:结核分枝杆菌Rv2318及其表位肽免疫原性研究
- Author:
Xueting FAN
1
;
Haican LIU
1
;
Ruihuan WANG
1
;
Machao LI
1
;
Kanglin WAN
1
;
Lili ZHAO
1
;
Ruibai WANG
1
;
Yi GUO
1
;
Guilian LI
1
;
Xiuqin ZHAO
1
Author Information
1. 传染病溯源预警与智能决策全国重点实验室,中国疾病预防控制中心传染病预防控制所,北京 102206
- Publication Type:Journal Article
- Keywords:
Mycobacterium tuberculosis;
Rv2318;
epitope peptides;
immunogenicity
- From:
Chinese Journal of Zoonoses
2025;41(10):999-1004
- CountryChina
- Language:Chinese
-
Abstract:
To screen new antigens for novel tuberculosis(TB)vaccine research,we used bioinformatics to predict the B and T cell epitopes of Rv2318,and evaluated the immunogenicity of Rv2318 and its T/B epitope peptides(Rv2318p).The recombinant plas-mids pET32a-Rv2318 and pET32a-Rv2318p were constructed through gene synthesis methods.The recombinant proteins were ex-pressed in a prokaryotic system and purified with nickel affinity chromatography.Proteins were identified with SDS-PAGE and western blotting.BALB/c mice were immunized subcutaneously with the recombinant proteins to evaluate immunogenicity.Sera were collected,and antigen specific antibody titers were evaluated with ELISA.Splenocytes were isolated,and cytokines and T cell proliferation were analyzed with ELISA and flow cytometry,respectively.Rv2318 included two epitope fragments,aa10-130 and 350-410.SDS-PAGE and western blotting indicated that the target proteins were expressed and purified correctly,and their relative molecular weights were-approximately 68 kD and 42 kD,respectively.Rv2318 and Rv2318p induced stronger humoral immune responses than observed in the control groups(P<0.000 1,n=6).Compared with Rv2318,Rv2318p showed significantly greater enhancement of specific IgG and IgG subclass antibodies(P<0.000 1,n=6).In addition,Rv2318p increased the ratio of IgG2a/IgG1,thus indicating that it primarily induced a cellular immune response biased toward the Th1 type.Cytokine experiments revealed that IFN-γ,IL-2,IL-6,and IL-4 significantly increased after immunization with Rv2318p(P all<0.01,n=6),particularly Th1 type cytokines(IFN-γ and IL-2).Furthermore,Rv2318 increased the expression of only IL-2 and IL-6,particularly IL-6(P all<0.01,n=6).Although Rv2318 in-duced more IFN-γ,we observed no significant difference between Rv2318 and PBS immunized mice.Importantly,Rv2318p stimu-lated mice to express IFN-γ at 842 pg/mL,approximately 3 times the level elicited by Rv2318.Whereas both proteins increased the proportions of CD4+and CD8+T cells,Rv2318p promoted greater proliferation of T lymphocytes.These data indicated that both Rv2318 and its epitope peptides enhanced humoral and cellular immune responses,whereas the epitope peptides notably triggered a stronger Th1 type cellular response.In conclusion,the recombinant protein Rv2318 and its epitope peptides showed favorable immunogenicity,and the immunogenicity of Rv2318p was superior to that of Rv2318.This study provides a theoretical basis for TB vaccine development.
