Affiliations: Department of Pediatrics, University of Catania, Catania, Italy
Note: [] Corresponding author: Lanzafame Angela, Via Santa Sofia 78,
95100 Catania, Italy. Tel.: +39 953782764; Fax: +39 953782385; E-mail:
angela.lanzafa@yahoo.it
Abstract: Specific sublingual immunotherapy (SLIT) represents an approach
currently available to redirect inappropriate immune response in atopic
patients. Since oral mucosal tissue displays high affinity for allergens, it is
conceivable that the sublingual administration route might induce immunological
tolerance towards allergens involving cells and mediators specific of oral and
intestinal mucosa. The presence in oral mucosa of dendritic cells (DCs) which
express the high-affinity receptor for immunoglobulin (Ig)E (FceRI) seems to
suggest that the generation of T regulatory cells in periphery is orchestrated
by a particular subset of DCs. It seems that repeated stimulation of naïve
CD4 T cells with allogenic immature DCs induce Tr1 cell maturation.
Nevertheless, other cells are involved in this process, such as Toll Like
Receptors (TLR), Major Histocompatibility Complex I and II (MHC I and II) and
costimulatory molecules, such as CD40, CD 80/B7.1 and CD 86/B7.2. An increase
of serum IgG4 and IgA, a reduced number of inflammatory cells infiltrating
target organs, as well as a reduction of eosinophilic cationic protein and a T
cell suppression in the peripheral blood also occur with SLIT. All these
molecules orchestrate the immune network within the regional immune system,
recreating a favourable environment for the induction of tolerance operated by SLIT.
