Figure 8
QS-21 injection leads to HMGB1 release that is required for optimal CD4 T-cell responses.
(A) Mice were injected i.m. with QS-21 and the draining lymph nodes were recovered 6 h post injection. The whole lymph nodes were cultured for 24 h in complete medium and HMGB1 was detected in the supernatant by ELISA (n = 10). (B) Experiment timeline. Mice received four i.p. peptide (500 μg per mouse – red arrows) injections at day 0 and day 14 (1 h before immunisation and then at 12 h intervals). The FSSE-NH2 peptide inhibits HMGB1-MD-2 interaction while the scrambled control (SFSE-NH2) does not. (C–F) FSSE and control peptide-treated mice were immunised as in (B). At day 21, cytokine production (C) and polyfunctionality (D) of HBs-specific CD4 T cells were evaluated after in vitro restimulation by intracellular staining. The data is represented as the median of 6 (Ag) or 20 (QS-21) mice. (E) Cytokine production by HBs-specific splenic CD8 and frequency of antigen (OVA)-specific circulating CD8 T cells assessed by flow cytometry (Ag: n = 6, QS-21: n = 20). (F) Anti-HBs IgG1 and IgG2c titres in the serum at day 21 were measured by ELISA (Ag: n = 3, QS-21: n = 10). Each point represents a single mouse and the horizontal bar represents the geometric mean. Statistical significance was determined by a non-parametric Mann-Whitney test. The data represents a pool of 2 independent experiments.
