Immunotherapy is to reorient allergen specific immune response in the course of IL-10 secreting cells such as Treg and Breg cell subsets. The immunologic mechanisms of SLIT are less well-established than those of subcutaneous immunotherapy. In children or adults with seasonal allergic rhinoconjunctivitis to grass pollen, no significant effect of SLIT on T-cell functions (i.e. cytokine production and proliferation) was observed in several studies.SLIT did not induce any detectable changes in dendritic cells (DCs) nor T-lymphocytes in the epithelium or lamina propria of the oral mucosa. Immunization through the sublingual route was nevertheless shown in other studies to decrease the production of the Th2 cytokine IL-13 and the proliferation of peripheral blood mononuclear cells (PBMCs) from patients allergic to house dust mite.