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Updated: Oct 15, 2025
Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope
Published on: March 24, 2017
Identification of Immunogenic Linear B-Cell Epitopes in C. burnetii Outer Membrane Proteins Using Immunoinformatics
Sílvia da Silva Fontes1, Fernanda de Moraes Maia1, Laura Santa'Anna Ataides1
1Laboratory of Monoclonal Antibodies Technology, Immunobiological Technology Institute, FIOCRUZ, Rio de Janeiro 21040-900, Brazil.
Abstract:
Coxiella burnetii is a global, highly infectious intracellular bacterium, able to infect a wide range of hosts and to persist for months in the environment. It is the etiological agent of Q fever-a zoonosis of global priority. Currently, there are no national surveillance data on C. burnetii's seroprevalence for any South American country, reinforcing the necessity of developing novel and inexpensive serological tools to monitor the prevalence of infections among humans and animals-especially cattle, goats, and sheep. In this study, we used immunoinformatics and computational biology tools to predict specific linear B-cell epitopes in three C. burnetii outer membrane proteins: OMP-H (CBU_0612), Com-1 (CBU_1910), and OMP-P1 (CBU_0311). Furthermore, predicted epitopes were tested by ELISA, as synthetic peptides, against samples of patients reactive to C. burnetii in indirect immunofluorescence assay, in order to evaluate their natural immunogenicity. In this way, two linear B-cell epitopes were identified in each studied protein (OMP-H(51-59), OMP-H(91-106), Com-1(57-76), Com-1(191-206), OMP-P1(197-209), and OMP-P1(215-227)); all of them were confirmed as naturally immunogenic by the presence of specific antibodies in 77% of studied patients against at least one of the identified epitopes. Remarkably, a higher frequency of endocarditis cases was observed among patients who presented an intense humoral response to OMP-H and Com-1 epitopes. These data confirm that immunoinformatics applied to the identification of specific B-cell epitopes can be an effective strategy to improve and accelerate the development of surveillance tools against neglected diseases.
Insights
This study identified immunogenic B-cell epitopes in Coxiella burnetii outer membrane proteins. These findings aid in developing new tools for Q fever surveillance in South America.
Area of Science:
- Microbiology
- Immunology
- Computational Biology
Background:
- Coxiella burnetii causes Q fever, a globally significant zoonosis with no current surveillance data in South America.
- There is a critical need for cost-effective serological tools to monitor C. burnetii infections in humans and livestock.
Purpose of the Study:
- To identify and validate specific linear B-cell epitopes in C. burnetii outer membrane proteins using immunoinformatics.
- To assess the natural immunogenicity of these predicted epitopes in Q fever patients.
Main Methods:
- Immunoinformatics and computational biology were used to predict B-cell epitopes in OMP-H, Com-1, and OMP-P1 proteins.
- ELISA was employed to test synthetic peptides representing predicted epitopes against patient samples.
- Indirect immunofluorescence assay was used for initial patient sample screening.
Main Results:
- Two naturally immunogenic linear B-cell epitopes were identified in each of the three target proteins.
- Antibodies against at least one identified epitope were present in 77% of the studied patients.
- An intense humoral response to OMP-H and Com-1 epitopes correlated with a higher frequency of endocarditis cases.
Conclusions:
- Immunoinformatics is an effective strategy for rapidly identifying B-cell epitopes.
- The validated epitopes can contribute to the development of improved diagnostic and surveillance tools for Q fever.
- This approach can accelerate the development of tools for neglected zoonotic diseases.
