Table 1

Systemic Administration of STAg Increases the Number of N418+ DC in Mouse Spleen

Number of cells (× 106)Ratio
PBS- injectedSTAg- injected
Whole spleen 570     7701.4
LOD  36      461.3
LOD B220+ cells 16.3 16.01.0
LOD N418+ cells  8.4 12.91.5
LOD N418+ DEC-205 cells  6.5 10.11.6
LOD N418+ DEC-205+ cells  2.0  2.81.4
  • Groups of four C57BL/6 mice were intravenously injected with either PBS or 25 μg STAg. Spleens were removed 6 h later, digested with collagenase, treated with EDTA, and fractionated over dense BSA. The numbers of nucleated cells in the unfractionated spleen cell suspension and LOD fraction were counted with a hemocytometer. The number of cells in LOD subpopulations was determined by multiplying the frequency of each subpopulation, as determined by flow cytometry, by the absolute number of LOD cells in each group. Ratios represent the number of cells in the STAg-injected group divided by the corresponding number in the PBS-injected control group. No N418+ cells were found in the high density fraction of spleen, even after STAg injection (data not shown). All DEC-205+N418+ cells were also CD8α+. Intracellular staining for IL-12 p40 from the same experiment is shown in Fig. 5.