Figure 5.

S. typhimurium ability to induce an increase in [Ca²⁺] correlates with its ability to elicit activation of NF-κB and subsequent IL-8 secretion. Model intestinal epithelia were treated with the indicated strain of S. typhimurium or a nonpathogenic strain of gut E. coli. Bacteria were applied apically. (a) Fluorometric assay of intracellular [Ca²⁺]. (b) IL-8 secretion measured by ELISA. IL-8 was assayed from the basolateral media after 5 hours. (c) Northern blot probed with IL-8. T84 cell mRNA prepared after infection for 5 hours with the indicated organisms. (d) EMSA with IL-8 probe. Nuclear extracts prepared 3 hours after infection.