Human Innate Lymphoid Cell Subsets Possess Tissue-Type Based Heterogeneity in Phenotype and Frequency

Area of Science:

• Immunology
• Cell Biology

Background:

• Innate lymphoid cells (ILCs) are crucial for immune responses, but human ILC characterization is limited.
• Technical challenges have historically hindered detailed analysis of ILCs in human tissues.

Purpose of the Study:

• To accurately identify and profile human ILCs across healthy and inflamed tissues.
• To delineate ILC subsets and explore their heterogeneity in different individuals and tissue types.

Main Methods:

• Utilized mass cytometry with extensive surface markers and transcription factors.
• Applied high-dimensional analysis for phenotypic delineation of ILC subsets.
• Assessed ILCs in both healthy and inflamed human tissue samples.

Main Results:

• Clearly delineated ILC2 and ILC3 subsets.
• Identified intra-epithelial ILC1-like cells, a category of NK cells, in mucosal and non-mucosal tissues.
• Revealed previously undescribed phenotypic molecules on human ILCs.
• Demonstrated significant heterogeneity of human ILCs across individuals and tissues.

Conclusions:

• Human ILCs exhibit substantial heterogeneity between individuals and tissues.
• Provides a comprehensive description of ILC heterogeneity in humans.
• Mass cytometry is effective for detailed ILC profiling, including novel cell populations.