Effects of gliadin stimulation on bone marrow-derived dendritic cells from HLA-DQ8 transgenic MICE

Background and aimGliadin presentation by HLA-DQ2/8 molecules to T cells plays a crucial role in triggering the inflammatory cascade in coeliac disease. We aimed to study the immunological effects of gliadin stimulation on dendritic cells (DCs) from HLA-DQ8 transgenic and BALB/c mice.MethodsBone marrow-derived DCs were stimulated with α-chymotrypsin-digested gliadin or ovoalbumin (100 μg/ml). Modification of DC maturation, through HLA-DQ8 and MHC class II expression, and activation, by CD80 and CD86, was assessed by flow cytometry. The ability of pulsed and unpulsed DCs to prime T cells was evaluated by mixed leucocyte reaction. The expression of interleukin-4, -10, -12p70 and interferon-α, as well as of Toll-like receptor-4, -7, -8, -9 was determined by ELISA and real-time RT-PCR, respectively.ResultsGliadin stimulation induced DC maturation (p < 0.001 in BALB/c, p < 0.01 in DQ8) but not activation, whereas ovoalbumin upregulated all markers (p < 0.01 for maturation and p < 0.001 for activation in both DC populations). No increase of T proliferation was elicited by pulsed DCs with respect to unpulsed DCs. Only in DQ8 DCs, gliadin induced Toll-like receptor-4 (p < 0.001), -7 (p < 0.001), -8 (p < 0.005) expression and interferon-α (p < 0.001) secretion.ConclusionGliadin resulted unable to activate DC, but stimulated Toll-like receptor expression and interferon-α secretion.