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oai:figshare.com:article/34026928 2026-09-29T17:38:45Z category_4 category_7 category_8 category_12 category_46 category_64 category_132 portal_5 item_type_1 month_year_09_2026

<p>Identification of reactive <i>Francisella</i> MHC-II peptides and their validation as CD4⁺ T cell epitopes.</p> Pavlina Laskova (25138447) Stanislava Porkertova (25138450) Ondrej Ballek (11568544) Lucie Balonova (1392496) Jana Pavloskova (25138453) Ales Neuwirth (13913055) Ivona Pavkova (2339947) Ivo Fabrik (1849519) Pavol Lukac (25138456) Luca Vannucci (14358999) Dominik Filipp (1849615) Jiri Stulik (151536) Marek Link (151527) Biochemistry Medicine Microbiology Cell Biology Immunology Cancer Infectious Diseases sup >+</ sup severe pneumonic form induced immune responses identified 57 mhc div >< p immunopeptidomics reveals conserved protective immune response peptide vaccine containing fully virulent strains ensure complete protection cells following immunization francisella tularensis </ tularensis </ using immunopeptidomics based immunopeptidomics vaccination studies subsequent screening significant role potential role least 80 ii peptides human tularemia highly expressed fsc200 strain five epitopes epitopes proved early control dominant epitopes characterizing antigen cells playing cell epitopes bacterial proteome 23 different <p>C57Bl/6 mice were subcutaneously injected with 3 × 10⁴ CFU of <i>F. tularensis</i> LVS and immune lymphocytes, pooled from groups of 3-4 mice, were stimulated with individual bacterial MHC-II peptides to assess immunogenicity. The numbers of IFN-γ producing cells (SFCs) were determined following stimulation of (A) 5 × 10⁵ whole splenocytes or (B) cocultures of 3 × 10⁵ spleen CD4⁺ T cells and 2 × 10⁵ naïve B cells with individual peptides. Data of 4 biological replicates (unique symbols) are shown for each suspension. The numbers of IFN-γ SFCs represent net reactivity of peptides (mean reactivity of stimulated cells – mean reactivity of control cells) in individual biological experiments. Within the biological experiment, peptides with significant response were detected with one-way ANOVA followed by Dunnett’s post hoc test (p < 0.05, blue symbols). The number of times the response was significant across biological replicates is annotated in the graphs. The specificity with which the peptide-induced IFN-γ production depended on the immune status of lymphocytes was verified by stimulation of (C) 5 × 10⁵ whole splenocytes or (D) cocultures of 3 × 10⁵ spleen CD4⁺ T cells and 2 × 10⁵ naïve B cells with a selected set of peptides. Lymphocytes were isolated from LVS immunized (immune) or age-matched control (control) mice. Data of individual assayed wells per condition and mean values are shown. Peptides with significant response against control without peptide (unstim) were detected with one-way ANOVA followed by Dunnett’s post hoc test. Asterisks indicate p-values (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001). Data are results of one experiment. (E) Reactivity of peptides across biological replicates. Peptides were tested for a significant response within each biological replicate and the frequency with which the response was significant or not is shown. The number of all replicates is indicated above the columns and in addition to the data shown in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1014597#ppat.1014597.g004" target="_blank">Fig 4A</a>, <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1014597#ppat.1014597.g004" target="_blank">4B</a> (8 replicates), two additional replicates were included, one of them with an incomplete set of peptides. For all assays, lymphocytes were isolated 3 weeks p.i. and peptides were used at a final concentration of 10 µM. Peptide RLQWQAPEGSKCHD (<i>Francisella</i> LpnA) and YAIAVNDLGTEYVHR (mouse Gls) was used as a positive and negative peptide, respectively.</p> 2026-09-29T17:54:09Z Image Figure 10.1371/journal.ppat.1014597.g004 https://figshare.com/articles/figure/_p_Identification_of_reactive_i_Francisella_i_MHC-II_peptides_and_their_validation_as_CD4_sup_sup_T_cell_epitopes_p_/34026928 CC BY 4.0