Table 1.
Mechanisms of immunologic tolerance mediated by T and B regulatory cells during allergen immunotherapy.
| Treg-mediated mechanisms |
|---|
| Release regulatory cytokines (IL-10, TGF-β, and IL-35) |
| Induce tolerogenic DCs subsets |
| Reduced number of ILC2 |
| Suppress activation of allergen-specific Th2 lymphocytes |
| Downregulate the expression of FCεRI receptors on mast cells |
| Decrease allergen-specific IgE synthesis |
| Promote B-cell production of IgG4 antibody |
| Breg-mediated mechanisms |
| Release regulatory cytokines (IL-10, TGF-β) |
| Induce the synthesis of IgG4 blocking antibodies |
| Inhibit activation and proliferation of effector T lymphocytes |
| Suppress Th2-dependent inflammation |
| Promote T-cell expression of Foxp3 and generation of functional Treg cells |
Breg, B regulatory; DCs, dendritic cells; FCεRI, high-affinity receptor for the Fc region of IgE; Foxp3, forkhead box P3; IgE, immunoglobulin E; IgG4, immunoglobulin G subtype 4; IL, interleukin; ILC2, innate lymphoid cells type 2; TGF, transforming growth factor; Th2, T helper type 2; Treg, T regulatory.