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


METHODS
Bone marrow-derived DCs were stimulated with alpha-chymotrypsin-digested gliadin or ovoalbumin (100 microg/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-alpha, as well as of Toll-like receptor-4, -7, -8, -9 was determined by ELISA and real-time RT-PCR, respectively.


RESULTS
Gliadin 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-alpha (p<0.001) secretion.


CONCLUSIONS
Gliadin resulted unable to activate DC, but stimulated Toll-like receptor expression and interferon-alpha secretion.
Center for the Study and Cure of Coeliac Disease, IRCCS San Matteo Hospital Foundation, University of Pavia, Italy. rachele.ciccocioppo@unipv.it
R
R
Ciccocioppo
M
M
Rossi
I
I
Pesce
G
G
Ricci
D
D
Millimaggi
F
F
Maurano
G R
GR
Corazza
D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D002446:Celiac Disease / Q000503:physiopathology*; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects* / Q000378:metabolism; D005903:Gliadin / Q000494:pharmacology*; D006683:HLA-DQ Antigens; D016898:Interferon-alpha / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D051193:Toll-Like Receptors / Q000378:metabolism
D006683:HLA-DQ Antigens; C109756:HLA-DQ8 antigen; D016898:Interferon-alpha; D007378:Interleukins; D051193:Toll-Like Receptors; D005903:Gliadin