Trained innate lymphoid cells in allergic diseases

Area of Science:

• Immunology
• Innate Immunity
• Type 2 Immunity

Background:

• Group 2 innate lymphoid cells (ILC2s) are crucial for type 2 immunity in tissues like the lungs and gut.
• ILC2s produce T_H2 cytokines, mediating responses against allergens, parasites, and viruses.

Purpose of the Study:

• To review how the immune environment shapes ILC2s into trained cells with distinct recall capabilities.
• To explore the molecular mechanisms and physiological significance of trained ILC2s in allergic diseases and type 2 immunity-associated infections.

Main Methods:

• Literature review focusing on ILC2 biology, trained immunity, and type 2 immune responses.
• Analysis of studies investigating the role of cytokines like IL-33 and retinoic acid in ILC2 differentiation and function.

Main Results:

• ILC2s can be trained by IL-33 or allergic inflammation to exhibit long-lived, memory-like type 2 immune responses.
• IL-33 and retinoic acid can induce IL-10-producing, immunosuppressive ILC2s.
• The cytokine milieu and other immune cells dictate whether trained ILC2s become immunostimulatory or immunosuppressive.

Conclusions:

• Trained immunity in ILC2s plays a significant role in the pathogenesis and resolution of allergic diseases and type 2 immunity-related infections.
• Understanding trained ILC2s offers potential therapeutic targets for modulating immune responses in these conditions.