TABLE 1.

Crucial role of the Afa/Dr DAEC adhesins in induced PMNL transepithelial migration with apical colonization by Afa/Dr DAEC strains^a

Strain	Mean transmigrated PMNL eq ± SE (104):
	Without MAb anti-CD55 (1H4)	With MAb anti-CD55 (1H4)
Control (HBSS buffer)	3.1 ± 1	2.2 ± 1
fMLP (10−7 M)	23.2 ± 1.3	21.2 ± 0.5
Wild-type C1845	19.1 ± 2.1	3.5 ± 1.1*
Wild-type IH11128	16.5 ± 1	2.8 ± 1*
HB101/pSSS1 (F1845 adhesin)	14.9 ± 0.5	3.4 ± 1.4*
HB101	2.9 ± 1.2	2.4 ± 1

^aA positive control was performed with the PMNL transmigrating inducing peptide fMLP at 10⁻⁷ M. All wild-type Afa/Dr DAEC strains and recombinant HB101/pSSS1 harboring Afa/Dr DAEC F1845 adhesin elicited a transepithelial migration of PMNL (not significantly different between PMNL transepithelial migration induced by fMLP versus wild-type Afa/Dr DAEC strains harboring the fimbrial F1845 and Dr hemagglutinin and recombinant E. coli HB101/pSSS1 expressing F1845 adhesin). PMNL transepithelial migrations induced by wild-type Afa/Dr DAEC C1845 and IH11128 strains or HB101/pSSS1 E. coli are inhibited by intestinal epithelial cells preincubated with MAb anti-CD55 (1H4) (∗, <0.01) versus infection without MAb CD55. Data are pooled from 6 to 12 individual monolayers for each condition, and the results are means ± standard errors.