Allergen immunotherapy (AIT) is an effective treatment for allergic rhinitis, inducing long-term clinical tolerance to the sensitizing allergen. Clinical tolerance induction can be achieved when AIT is administered for at least three years. AIT is associated with the modulation of innate and adaptive immune systems. This comprises of inhibition of IgE-dependent activation of mast cells and basophils in the local target organ, suppression of Th2 cells, immune deviation towards Th1 cells, induction of T and B regulatory cells and production of allergen neutralizing antibodies. However, recent developments in the underpinning mechanisms of AIT have revealed that immunotherapy, administered by SCIT or SLIT, induces immune regulation through novel cell targets and molecular mechanisms. This comprehensive review discusses how immune tolerance driven by SCIT and SLIT is associated with the induction of a novel regulatory subset of innate lymphoid cells, suppression of pro-inflammatory Th2, Th2A and T follicular helper cells, promotion of exhaustion of allergen-specific Th2 cells and differential expression of nasal and systemic antibodies IgA. Uncovering the underpinning mechanisms of successful AIT and immune tolerance will allow the development of targeted therapeutics for allergic rhinitis with and without asthma.
- Shamji, M. H.
- Sharif, H.
- Layhadi, J. A.
- Zhu, R.
- Kishore, U.
- Renz, H.
Keywords
- allergen immunotherapy
- antibody response
- innate lymphoid cells