HT29-MTX Cell Lines Research Articles

The influence of prednisolone on the secretion of MUC5AC from TH29-MTX cell culture

INTRODUCTION: Glucocorticoids have been used in the treatment of otitis media with effusion with promising but inconsistent resluts. The HT29-MTX cell line is a completely differentiated and almost exclusively mucous secreting cell line, which therefore has the potential to act as an ideal model for the study of mucus-secreting epithelia. To assess this potential of steroids in suppressing mucin secretion we have studied the response of the cell culture to prednisolone. METHODS: Confluent cell cultures were trypsinized, subcultured in six-well plates and incubated with four doses of prednisolone from 10-5 M to 10-11 M and over varying time courses from 12 to 36 h. ELISA was performed using a monoclonal mouse antibody to human gastric mucin by dot-blot ELISA. RESULTS: Prednisolone caused a reduction in mucin production from the cell line consistently. Media control values ranged from 3495 to 3559 compared with untreated controls of 18 998-27 176 and steroid treatment values of 12 244-27 792. Increasing concentrations of prednisolone result in increasing suppression of MUC5AC (P = 0.005). There was no independent time-related effect. CONCLUSION: There does appear to be a genuine suppression of mucus production by prednisolone and this appears to be dose-dependent but not time-dependent at the times studied. The effect size was small.

Adhesion of human bifidobacterial strains to cultured human intestinal epithelial cells and inhibition of enteropathogen-cell interactions.

Thirteen human bifidobacterial strains were tested for their abilities to adhere to human enterocyte-like Caco-2 cells in culture. The adhering strains were also tested for binding to the mucus produced by the human mucus-secreting HT29-MTX cell line in culture. A high level of calcium-independent adherence was observed for Bifidobacterium breve 4, for Bifidobacterium infantis 1, and for three fresh human isolates from adults. As observed by scanning electron microscopy, adhesion occurs to the apical brush border of the enterocytic Caco-2 cells and to the mucus secreted by the HT29-MTX mucus-secreting cells. The bacteria interacted with the well-defined apical microvilli of Caco-2 cells without cell damage. The adhesion to Caco-2 cells of bifidobacteria did not require calcium and was mediated by a proteinaceous adhesion-promoting factor which was present both in the bacterial whole cells and in the spent supernatant of bifidobacterium culture. This adhesion-promoting factor appeared species specific, as are the adhesion-promoting factors of lactobacilli. We investigated the inhibitory effect of adhering human bifidobacterial strains against intestinal cell monolayer colonization by a variety of diarrheagenic bacteria. B. breve 4, B. infantis 1, and fresh human isolates were shown to inhibit cell association of enterotoxigenic, enteropathogenic, diffusely adhering Escherichia coli and Salmonella typhimurium strains to enterocytic Caco-2 cells in a concentration-dependent manner. Moreover, B. breve 4 and B. infantis 1 strains inhibited, dose dependently, Caco-2 cell invasion by enteropathogenic E. coli, Yersinia pseudotuberculosis, and S. typhimurium strains.