Innate and adaptive type 2 immunity in lung allergic inflammation

Area of Science:

• Immunology
• Allergy Research
• Respiratory Medicine

Background:

• Allergic inflammation, a type 2 immune disorder, is characterized by immunoglobulin E (IgE) and Th2 cells.
• Asthma, a pulmonary allergic inflammatory disease, involves bronchial hyper-reactivity.
• Non-atopic asthma involves innate immune cells like basophils, group 2 innate lymphoid cells (ILC2s), and eosinophils, distinct from IgE-mediated atopic asthma.

Purpose of the Study:

• To review the role of Th2 cytokines and innate immune cells in allergic inflammation.
• To discuss the cross-talk between innate and adaptive immune responses in asthma.
• To highlight the innate cell network's role in facilitating type 2 inflammatory responses.

Main Methods:

• Literature review of immunological studies on allergic inflammation and asthma.
• Analysis of the roles of specific cytokines (IL-4, IL-13) and immune cells (mast cells, basophils, ILC2s, dendritic cells).
• Examination of the innate cell network (IL-33/TSLP-basophil-ILC2-IL-5/IL-13 axis) in allergic sensitization and chronic phases.

Main Results:

• Protease allergens can induce asthmatic responses independently of Th2 cells.
• An innate cell network involving IL-33/TSLP-basophil-ILC2-IL-5/IL-13 axis facilitates type 2 inflammatory sensitization.
• Innate immune cells contribute to adaptive Th2 cell responses in the chronic phase of allergic inflammation.

Conclusions:

• Innate immune cells play a crucial role in initiating and perpetuating allergic inflammation, including asthma.
• The interplay between innate and adaptive immunity is central to understanding and potentially treating type 2 allergic diseases.
• Targeting the innate cell network offers potential therapeutic strategies for allergic asthma.