Beyond Unconventional: What Do We Really Know about Group 2 Innate Lymphoid Cells?

Area of Science:

• Immunology
• Cell Biology

Background:

• Group 2 innate lymphoid cells (ILC2s) are key immune cells involved in helminth expulsion and allergic lung inflammation.
• ILC2s, as innate cells, respond to alarmins to produce type 2 cytokines, influencing adaptive immunity.
• Emerging evidence highlights ILC2 plasticity, including the development of pro-inflammatory roles and support for TH1 responses.

Purpose of the Study:

• To provide a comprehensive overview of Group 2 innate lymphoid cells (ILC2s).
• To detail the diverse subsets of ILC2s, including memory, regulatory, inflammatory, and type 1 ILC2s.
• To discuss ILC2 functions based on activation status, tissue microenvironments, and specific roles in immunity.

Main Methods:

• Literature review and synthesis of recent findings on ILC2 biology.
• Analysis of ILC2 subsets and their functional characteristics.
• Exploration of ILC2 plasticity and unconventional immune functions.

Main Results:

• ILC2s exhibit remarkable functional plasticity, extending beyond canonical type 2 immunity.
• Novel subsets of ILC2s, such as memory, regulatory, inflammatory, and type 1 ILC2s, have been identified.
• ILC2s can adopt pro-inflammatory identities and support T helper 1 (TH1) immune responses.

Conclusions:

• The plasticity of ILC2s allows for a broader range of immune functions than previously understood.
• Understanding diverse ILC2 subsets is crucial for comprehending their roles in health and disease.
• Continued research is necessary to fully elucidate the complex and evolving biology of ILC2s.