Afa/Dr Diffusely AdheringEscherichia coliInfection in T84 Cell Monolayers Induces Increased Neutrophil Transepithelial Migration, Which in Turn Promotes Cytokine-Dependent Upregulation of Decay-Accelerating Factor (CD55), the Receptor for Afa/Dr Adhesins

Abstract

Ulcerative colitis and Crohn's disease are inflammatory bowel diseases thought to involve strains of Escherichia coli. We report here that two wild-type Afa/Dr diffusely adhering E. coli (DAEC) strains, C1845 and IH11128, which harbor the fimbrial F1845 adhesin and the Dr hemagglutinin, respectively, and the E. coli laboratory strain HB101, transformed with the pSSS1 plasmid to produce Afa/Dr F1845 adhesin, all induced interleukin-8 (IL-8) production and transepithelial migration of polymorphonuclear leukocytes (PMNL) in polarized monolayers of the human intestinal cell line T84 grown on semipermeable filters. We observed that after PMNL migration, expression of decay-accelerating factor (DAF, or CD55), the brush border-associated receptor for Afa/Dr adhesins, was strongly enhanced, increasing the adhesion of Afa/Dr DAEC bacteria. When examining the mechanism by which DAF expression was enhanced, we observed that the PMNL transepithelial migration induced epithelial synthesis of tumor necrosis factor alpha and IL-1␤, which in turn promoted the upregulation of DAF.

Interleukin‐8 Secretion by Epithelial Cells Infected with Diffusely Adherent Escherichia coli Possessing Afa Adhesin‐Coding Genes

“…Bétis et al reported that the DAEC strains C1845 and IH11128 also triggered a proinflammatory signal in intestinal epithelial cells (3,4). In the present study we attempted to determine whether all afa-positive DAEC strains isolated from diarrheal stools could induce IL-8 secretion in cultured human epithelial cells to the same extent as EAggEC organisms.…”

“…French groups have continued to investigate these Afa-positive DAEC and have provided information regarding their molecular bacteriology (2,(14)(15)(16)(31)(32)(33)(34). Furthermore, Bétis et al (3,4) found that two DAEC strains induced interleukin-8 (IL-8) in human colonic epithelial cell line, T84.…”

Pathogenesis of Human Enterovirulent Bacteria: Lessons from Cultured, Fully Differentiated Human Colon Cancer Cell Lines

“…F1845-induced transepithelial migration of PMNLs triggers the synthesis of TNF-␣ and IL-1␤, which in turn promotes the upregulation of brush border-associated hDAF, increasing the adhesion of Afa/Dr DAF/CEACAMs DAEC to the brush border, and abnormal expression of hDAF at the basolateral domain of the fully differentiated T84 cells (808). PMNLs that have transmigrated across fully differentiated T84 monolayers show an elevated global caspase activity, indicative of apoptosis, and a reduced capacity to phagocytose Afa/Dr DAF/CEACAMs DAEC (809).…”

Infection strategies of enteric pathogenic Escherichia coli

“…This stimulates the enterocytes to synthesize TNFa and IL-1β and upregulate DAF to strengthen bacterial adhesion. 75 DAEC can interact with the transmigrating PMNs and induce type I pili-dependent IL-8 release. 76 Transmigrated PMNs are also induced to undergo apoptosis after interaction with DAEC and have a diminished phagocytic capacity, prolonging bacterial persistence in the gut.…”