Figure 4.

Human cells expressing SLC11A1 were more readily activated and preferentially expressed IFN-γ. Human PBMCs were isolated and cultured 24 hours with the indicated stimuli and then stained for SLC11A1 and CD69, CD25, or IFN-γ. A. SLC11A1⁺ human cells demonstrated slightly enhanced expression of CD69 in response simulation of PBMCs with very low concentrations of LPS. B. A significantly greater percent (Students t test) of CD69⁺ cells was evident in the SLC11A1⁺ lymphocytes in response to 10 ng/ml LPS, combined data from 2 experiements, n=7 donors. These data were also found to be significant n=0.0078 using non-parameteric Wilcoxon test. Shown is a representative FACS plot demonstrating the differences between SLC11A1⁺ and SLC11A1⁻ human cell populations after 10 ng/ml LPS stimulation. C. PMA/ionomycin treatment resulted in significant changes to IFN-γ expression. Similar to the bovine cells, human SLC11A1⁻ cells did not express IFN-γ, whereas SLC11A1⁺ cells expressed IFN-γ in response to very low concentrations of PMA/ionomycin. D. SLC11A1⁺ innate lymphocytes are significantly more activated in response to bacterial infection. When human monocyte/macrophages were infected with S. Typhimurium the SLC11A1⁺ cells in the cultures expressed significantly more CD69 than did the SLC11A1⁻ cell (Students t test). Medium only or brief exposure to Salmonella LPS resulted in minimal changes. Shown are combined data from 2 experiments. All figures are representative results from at least 3 experiments performed with PBMCs from at least 3 donors per experiment. Error bars represent standard deviation, **p<0.01, *p<0.05.