<p>Supporting results.</p>

Subsequent screening for IFN-γ responses identified ten peptides as immunogenic epitopes of CD4⁺ T cells following immunization of mice with <i>F. tularensis</i> LVS, thereby revealing previously unknown specificity and breadth of the induced immune responses. Five epitopes, derived from the antigens FTL_1678, DacD, DnaK, FTL_1498, and MinD, represented the dominant epitopes that elicited a response in at least 80% of immunizations.

Finally, a peptide vaccine containing these epitopes proved to be immunogenic in mice and contributed to the early control of bacterial replication following challenge with the virulent <i>F. tularensis</i> FSC200 strain, although this alone was insufficient to ensure complete protection. Using immunopeptidomics, we have thus identified several immunogenic CD4⁺ T cell epitopes and antigens of <i>F. tularensis</i> LVS.

Beyond their potential role in the protective immune response, the identified epitopes may also enable the development of tools for characterizing antigen-specific CD4⁺ T cells in vaccination studies or T cell biology research.</p></div>