FIG 7.

Effect of the R203E mutation in NleD on p38 cleavage and IL-6 secretion in EPEC infection. (A) Immunoblots of JNK and p38 cleavage in HT-29 cells infected with various EPEC derivatives. Cell lysates were probed with anti-JNK and anti-p38 antibodies. Anti-HA antibody was used to show the expression of NleD-2HA and NleD-2HA variants. Arrows, cleavage products. Actin was used as a loading control. The immunoblots are representative of those from at least 3 independent experiments. (B) HT-29 cells were infected with derivatives of EPEC, as indicated, for 2 h and left unstimulated or stimulated with TNF for 8 h (gray bars). Results are the means ± SEMs from at least three independent experiments carried out in duplicate (*, P < 0.05; **, P < 0.005; P values were determined by an unpaired, two-tailed t test). UI, uninfected; UN, unstimulated.