In Vitro Presentation of Gliadin-Derived Peptides by Different Cell Lines

CHIRDO, FG; ZWIRNER, NW; RUMBO, M; FOSSATI, CA; FERNANDO GABRIEL CHIRDO

CLINICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2002 p. 151 - 158

0009-8981

Background. Gliadin peptide presentation and T cell activation are critical events in the coeliac disease pathogenesis. Several studies have been performed to identify the toxic gliadin peptides. However, difficulties have been found, in part, due to the complexity of the antigenic fraction. In this work, an in vitro model for the analysis of gliadin peptide presentation is studied. Methods. Human cell lines: U937 and THP-1 (monocytic), DUCAF and VAVY (immortalised B cells) and HT-29 and Caco-2 (intestinal epithelial cells) were incubated with biotin-labelled gliadin (bG). FITC-labelled streptavidin was used to detect biotinylated peptides at cell surface by flow cytometry. Results. All cell lines tested showed fluorescence signal derived from bG, being potentiated in cells stimulated with IFN- for 48 h. Time course and dose response experiments performed using THP-1 cells demonstrated that almost maximal signal was achieved after incubation at 4 h, 37°C. THP-1 cells incubated at 4 °C or after paraformaldehyde fixation showed a substantial signal reduction, suggesting that a complete metabolic activity is necessary for detection of the maximal fluorescence signal at the cell surface. The presence of HLA class II bound biotinylated peptides was observed in cell lysates of THP-1 cells incubated with bG. Conclusion. In all cell lines tested, a specific biotin-peptides derived signal, higher after IFN- treatment and lower in inhibition experiments, was observed. Signal was higher for monocytic and B cell lines. The use of this procedure could be an useful tool to study the in vitro processing and presentation of naturally gliadin-derived peptides.