Figure 4

Clodronate-mediated depletion of CD169⁺ subcapsular sinus macrophages greatly reduces innate and effector responses induced by QS-21.

(A) Monocyte, neutrophil and dendritic cell recruitment to the DLN measured by flow cytometry 24 h post QS-21 injection (Ag: n = 5, QS-21: n = 10). (B) Expression of the co-stimulatory molecules CD80 and CD86 on dendritic cells measured by flow cytometry 24 h post QS-21 injection (Ag: n = 4, QS-21: n = 5) (C) Mice were injected with clodronate or control liposomes 6 days prior to vaccination and immunised as in 1 A. At day 21, median cytokine production (C) and polyfunctionality (D) of HBs-specific CD4 T cells, cytokine production by HBs-specific CD8 T cells (E), and frequency of OVA-specific circulating CD8 T-cells (E) were assessed by flow cytometry (Ag: n = 4, QS-21: n = 8). (F) Anti-HBs IgG1, IgG2c and total IgG titres in the serum of mice injected with QS-21 or Alum were measured by ELISA at day 21 (Ag: n = 8, QS-21: n = 16, Alum: n = 8). 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 is representative of at least 2 independent experiments.