T-cell response to <i>in vivo</i> antigen challenge is not affected at post-acute stages of SIRS/sepsis.

<p>(<b>A</b>) Experimental design for <i>in vivo</i> antigenic challenge of T-lymphocytes at post-acute stages of SIRS. Mice were adoptively transferred with P14 transgenic T-lymphocytes bearing different Thy genotypes (Thy 1.1/1.2 <i>versus</i> Thy 1.1/1.1) before (pre-SIRS) and after SIRS/sepsis induction (post-SIRS). Ten days after SIRS/sepsis mice were infected with <i>Listeria monocytogenes</i> expressing the GP33 peptide. CD8⁺ T cell response was examined on day 7 post-infection 2 h after i.v. injection of 0.5 or 5 µg GP33 peptide. (<b>B</b>) Transgenic, GP33 specific CD8⁺ T-lymphocytes adoptively transferred before (pre-SIRS) or after (post-SIRS) the SIRS insult are discriminated on the basis of their different Thy genotype. (<b>C</b>) 2 h after injection of 5 µg GP33 peptide, animals were sacrificed and IFNγ or (<b>D</b>) TNFα production in CD8⁺ pre-SIRS or post-SIRS P14 T-cells was assessed by flow cytometry. (<b>E</b>) IFNγ and (<b>F</b>) TNFα production in CD8⁺ P14 T-cells after <i>in vivo</i> injection of a lower dose of 0.5 µg GP33 peptide. (<b>G</b>) Surface expression of CD69 or (<b>H</b>) CD25 was assessed by FACS analysis in the same lymphocyte populations. Data are presented as mean + SEM (4-5 mice/group [C, D, G, H], 2–4 mice/group [E, F]). A One-way ANOVA with post-hoc Bonferroni analysis was performed to determine significances (* p≤0.05, ** p≤0.01, ***p≤0.001).