Carina Carvalho dos Santos Poster 2025

 Prof Carina Carvalho dos Santos

Federal University of Bahia, Brazil

An immunoinformatics approach to identify potential epitopes for a tuberculosis vaccine

Poster Abstract

Tuberculosis (TB) is among the 10 leading causes of death worldwide. New strategies are urgently needed, since the only available vaccine, Mycobacterium bovis bacille Calmette-Guérin (BCG), has variable efficacy against pulmonary TB in adults. Although some TB vaccine candidates have reached clinical stages, many have not been successful. There is broad interest in diversifying the TB vaccine pipeline, and immunoinformatics offers an approach to identify immunogenic epitopes for designing effective vaccines.

This study aimed to select antigenic and non-toxic epitopes, with broad population coverage, targeting T and B lymphocytes, to develop vaccine candidates against Mycobacterium tuberculosis (Mtb). In this in silico study, FASTA sequences of 25 proteins from different metabolic stages of Mtb were predicted to identify epitopes for helper T lymphocyte (HTL), cytotoxic T lymphocyte (CTL), and B-cell from humans and mice. The IEDB MHC-I/MHC-II and ABCpred platforms were used for epitope prediction. The selected epitopes were evaluated using servers for immunogenicity (VaxiJen), allergenicity (AllerTOP v2.0), toxicity (ToxinPred), and population coverage (IEDB/population).

Among the 25 proteins analyzed, 10 showed CTL epitopes (9-mer) with an MHC-I affinity score ≥ 0.1, high antigenicity (≥ 0.93), absence of toxicity, recognition by ≥ 10 human alleles, and population coverage ≥ 48.43%. Additionally, 10 proteins contained HTL epitopes (15-mer) with antigenicity ≥ 0.8, absence of toxicity, recognition by ≥ 7.7 human alleles, and population coverage ≥ 32%. Furthermore, 11 proteins displayed B-cell epitopes (16-mer) with a binding score ≥ 0.9, antigenicity ≥ 0.91, and absence of toxicity. The most antigenic epitopes from each protein were selected to propose multi-epitope vaccine constructs. It will be evaluated through molecular docking and molecular dynamics simulations to assess interactions and stability. This research was supported by CNPq, FAPESB (DCR N° 0010/2024) and UFBA.

Biography

Dr. Carina works as professor of Immunology at the Federal University of Bahia (UFBA) (Salvador, Bahia, Brazil). She coordinates an infectious disease diagnostic laboratory, that offers laboratory tests through the Brazilian Unified Health System (SUS). She works on projects related to the development of vaccines against tuberculosis and the prevalence of infections of importance to public health.