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Updated: May 28, 2026
Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice
Published on: February 22, 2019
Screening Epitopes Through Comparative Analysis of Children and Mice Immune Responses to Pertussis Toxin Subunits
Salvatore Giovanni De-Simone1,2,3, Guilherme Curty Lechuga1, Paloma Napoleão-Pêgo1
1Center for Technological Development in Health (CDTS), Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil.
Insights
This study reveals shared and unique antigenic targets of pertussis toxin (Ptx) in children and mice, offering insights for developing more effective pertussis vaccines.
Area of Science:
- Immunology
- Vaccinology
- Microbial Pathogenesis
Background:
- Pertussis toxin (Ptx) is a key virulence factor and protective antigen of *Bordetella pertussis*.
- Understanding Ptx's antigenic landscape is crucial for enhancing pertussis vaccine efficacy.
- This study compares linear epitope profiles recognized by antibodies in vaccinated children and mice.
Purpose of the Study:
- To compare linear epitope profiles of Ptx recognized by antibodies from vaccinated children and mice.
- To identify conserved and species-specific immune targets across Ptx subunits (S1-S5).
- To inform the design of improved pertussis vaccines.
Main Methods:
- Synthesized overlapping peptide libraries covering the full-length Ptx sequence.
- Analyzed sera from children and mice immunized with whole-cell pertussis vaccine.
- Performed comparative and structural analyses of antibody-binding regions and epitope distribution.
Main Results:
- Identified 12 major epitopes in mice and 24 in children, with 11 shared epitopes.
- Observed species-specific epitopes in S1, S2, S3, S4, and S5 subunits.
- Structural analysis showed non-uniform antibody recognition, highlighting S3 and S1 subunits, and identified 14 novel epitopes.
Conclusions:
- Highlighted significant differences in murine and human immune responses to Ptx epitopes.
- Demonstrated both conserved and species-specific antigenic targets of Ptx.
- The identified epitopes provide a foundation for designing next-generation pertussis vaccines.
Background:
Pertussis toxin (Ptx) is a major virulence factor and protective antigen of Bordetella pertussis. Understanding its antigenic landscape is essential for improving vaccine design. This study aimed to compare the linear epitope profiles of Ptx recognized by antibodies from vaccinated children and mice, identifying conserved and species-specific immune targets across subunits S1-S5.
Methods:
Two libraries of overlapping 14-mer peptides spanning the full-length Ptx sequence were synthesized. Sera from children and mice immunized with the whole-cell pertussis vaccine were analyzed to map antibody-binding regions. Comparative and structural analyses were performed to evaluate epitope distribution and recognition patterns.
Results:
Murine sera recognized 12 major epitopes, whereas children's sera identified 24. Eleven epitopes were shared between species, mainly in subunits S1 (Ep3-5, 7, 9, 10), S3 (Ep20, 21, 25, 26), and S5 (Ep32), although minor positional shifts were observed. Eight epitopes were unique to children's sera, located in S1 (Ep1, 6, 8), S3 (Ep22-24), and S4 (Ep27, 29-30). In the S2 subunit, four distinct epitopes were identified for each species, while only one mouse-specific epitope was detected in S4 (Ep28). Structural analysis revealed non-uniform antibody recognition, with dominant targeting of S3 and conserved antigenic hotspots, as well as selective recognition of the catalytic S1 subunit. Fourteen novel epitopes were identified.
Conclusions:
These findings highlight both shared and species-specific Ptx epitopes, revealing differences between murine and human immune responses. The identified conserved regions and novel epitopes provide a basis for improved pertussis vaccine design.
