Dendritic cells (DC) play a pivotal role in shaping the immune response in
both physiological and pathological conditions. In peripheral blood at least
two subsets, the myeloid and plasmacytoid, have been described as having
different T stimulatory functions and a variable degree of maturation. Certainly,
antigen presentation plays a crucial role in the pathogenesis of coeliac
disease and circulating immune cells are thought to reflect the state of
immune response within the gut. Therefore,we aimed to investigate the quantitative
and phenotypical modifications of peripheral bloodDC, together with
their functional properties, in this pathological condition. Blood samples
from 11 untreated patients before and after a course of gluten-free diet, 27
treated patients and 14 controls underwent flow-cytometric analysis, while
immunomagnetically sorted DC from the CD patients and eight human leucocyte
antigen (HLA)-DQ2/8+ bone marrow donors were used to evaluate
maturation status through the CD83 expression, cytokine profile for interleukin
(IL)-6, IL-10, IL-12 and interferon (IFN)-a by enzyme-linked immunosorbent
assay (ELISA), and functional properties by mixed leucocyte reaction
before and after pulsing with digested gliadin. We found that in both
untreated and treated patients, a significant reduction of the entire DC population,
mainly the plasmacytoid subset, in comparison to healthy controls was
observed. In active disease, an impaired allogenic lymphocyte reaction and a
significant reduction of IFN-a production, paralleled by the presence of a
more immature status, were also demonstrated. All the latter modifications
have been reverted by pulsing DC with digested gliadin
