Fig 2.

ESF has heat-stable, proteinaceous qualities. (A) IκBα immunoblotting after treating cells with TNF or with ETEC supernatants first incubated with either proteinase K, boiling, DNase I, or RNase A. (B) IκBα immunoblotting after treating cells with TNF and supernatants derived from ETEC H01047 possessing or lacking the major virulence plasmid (H10407-P). (C) IκBα immunoblotting after treating cells with ETEC supernatant subjected to size fractionation (3-kDa cutoff). (D) IκBα immunoblotting after treating cells with TNF and supernatants derived from the indicated human, porcine, and bovine ETEC strains. For all quantitative data in this figure, asterisks indicate IκBα abundance significantly different from that in the TNF-only lane.