Skin-draining lymph nodes contain dermis-derived CD103(-) dendritic cells that constitutively produce retinoic acid and induce Foxp3(+) regulatory T cells.

Publié dans:

Auteurs: Martin Guilliams, Karine Crozat, Sandrine Henri, Samira Tamoutounour, Pierre Grenot, Elisabeth Devilard, Béatrice de Bovis, Lena Alexopoulou, Marc Dalod, Bernard Malissen

Résumé

Small intestinal CD103(+) dendritic cells (DCs) have the selective ability to promote de novo generation of regulatory T cells via the production of retinoic acid (RA). Considering that aldehyde dehydrogenase (ALDH) activity controls the production of RA, we used a flow cytometry-based assay to measure ALDH activity at the single-cell level and to perform a comprehensive analysis of the RA-producing DC populations present in lymphoid and nonlymphoid mouse tissues. RA-producing DCs were primarily of the tissue-derived, migratory DC subtype and can be readily found in the skin and in the lungs as well as in their corresponding draining lymph nodes. The RA-producing skin-derived DCs were capable of triggering the generation of regulatory T cells, a finding demonstrating that the presence of RA-producing, tolerogenic DCs is not restricted to the intestinal tract as previously thought. Unexpectedly, the production of RA by skin DCs was restricted to CD103(-) DCs, indicating that CD103 expression does not constitute a “universal” marker for RA-producing mouse DCs. Finally, Toll-like receptor (TLR) triggering or the presence of a commensal microflora was not essential for the induction of ALDH activity in the discrete ALDH(+) DC subsets that characterize tissues constituting environmental interfaces.

Lien vers Pubmed [PMID] – 20068222

Lien vers HAL – hal-00502990

Lien vers le DOI – 10.1182/blood-2009-09-245274