Figure 4.

Adjuvant induced increase of antigen deposition on follicular dendritic cells (FDCs) is diminished in low dose clodronate treated mice and CD169 knockout mice. Representative immunohistochemistry images from draining lymph nodes from wildtype, clodronate treated mice, and CD169 knockout mice 24 h post subcutaneous immunizations of ovalbumin (OVA) with PorB (A), CpG (B), or Alum (C) and 48 h post clodronate treatment. FDC is shown in green. OVA-A594 is shown in red. Images were taken at 63x objective using a Leica SP5 microscope. Typical areas of co-localization are emphasized with yellow arrows. Scale bar represents 20 µM. One out of six representative experiments is shown. (D) Quantification of colocalization between fluorescently labeled OVA-A594 with FDC within draining lymph nodes 24 h post subcutaneous injections. Colocalization was assessed using Pearson Correlation coefficients calculated within JaCoP plugin in ImageJ after background subtraction and unsharp mask filter. n = 8–12/group. Wild type control injections are shown in the bars with no pattern. Low dose clodronate treated animals are shown in the stripped bars. CD169 knockout animals are shown in checkered bars. Statistics were calculated by ordinary one-way ANOVA with Sidak’s multiple comparisons test. *p < 0.05, **p < 0.01, ***p < 0.001 ****p < 0.0001.