FIG. 3.

Lymphostatin is required for inhibition of lymphocyte but not epithelial cell proliferation by EPEC. PBMC (A) or Caco-2 cells (B) were incubated with lysates from wild-type EPEC strain E2348/69 (circles), EPEC lifA mutant UMD704 (squares), or commensal E. coli strain EFC1 (triangles), stimulated with PMA-PWM, and incorporation of thymidine was measured by scintillation counting after 2 days. Values were calculated as percentages of controls as described in Materials and Methods. Data shown represent the mean percentages ± SEMs from quadruple determinations of two independent experiments.