Comparative analysis of nasal and oral mucosa dendritic cells.

Background: Mucosal dendritic cells (DC) play a crucial role in tolerance induction as seen in mucosal immunotherapy of atopic diseases. Nevertheless little is known about the phenotypical differences of oral and nasal mucosal DC (nmDC). Recently, we could show that oral mucosal myeloid CD1a(+) DC (omDC) differ from their skin counterparts especially by the expression of high affinity receptor for immunoglobulin E (IgE; FcepsilonRI).

The role of antigen presenting cells at distinct anatomic sites: they accelerate and they slow down allergies.

It has been repeatedly demonstrated that allergic reactions are driven by the continuous flow of antigen uptake and presentation processes, which are perpetuated mainly by dendritic cells (DC). The ability of allergens to cause allergic inflammation is contingent upon the presence of an immunological milieu and microenvironment that either privileges Th2 responses or prohibits these reactions by the induction of contraregulatory anti-inflammatory activities of the immune system. In the light of recent developments it appears that DC have to manage two opposing tasks: on the one hand they can favor pro-inflammatory reactions and actively induce a T-cell response, yet on the other hand they serve an important function as 'silencers' in the immune system by sending out anti-inflammatory, tolerance inducing signals.