Group 2 Innate Lymphoid Cells Exhibit Tissue-Specific Dynamic Behaviour During Type 2 Immune Responses

Area of Science:

• Immunology
• Cell Biology
• Innate Immunity

Background:

• Group 2 innate lymphoid cells (ILCs) are key players in type 2 immunity, crucial for responses to helminths and allergens.
• While ILC2s reside in lymphoid organs and mucosa, their dynamic behavior and interactions in vivo remain poorly understood.

Purpose of the Study:

• To investigate the real-time behavior and interactions of ILC2s and Th2 T cells during type 2 immune responses.
• To elucidate the role of ILC2s in cytokine production and T cell activation within lymphoid organs and mucosal tissues.

Main Methods:

• Utilized a CD2/IL-13 dual fluorescent reporter mouse for in vivo imaging.
• Performed real-time imaging of ILC2s and Th2 T cells following helminth infection or egg injection.
• Analyzed ILC2 location, movement, size, and interactions with T cells in lymphoid organs and intestinal mucosa.

Main Results:

• ILC2s were the primary source of IL-13 in lymphoid organs and localized to T cell areas.
• Helminth infection increased ILC2 motility and size in lymphoid organs but reduced T cell interaction duration.
• In the intestinal mucosa, ILC2-T cell interactions increased, with some prolonged contacts, alongside enhanced ILC2 movement.

Conclusions:

• ILC2 activation boosts cell motility, potentially expanding cytokine distribution for optimized type 2 immunity.
• Prolonged ILC2-T cell interactions in the gut suggest contact-dependent T cell activation occurs in inflamed tissues.
• Findings offer critical insights into in vivo ILC2 biology and their role in facilitating adaptive immunity.