Transcriptome landscape of double negative T cells by single-cell RNA sequencing

Area of Science:

• Immunology
• Cell Biology
• Genomics

Background:

• Double negative T (DNT) cells (TCRαβ+, CD4-, CD8-) are recognized for critical immune roles.
• Their molecular and functional signatures remain poorly understood and controversial due to low cell frequency and non-standardized definitions.

Purpose of the Study:

• To delineate the molecular and functional heterogeneity of DNT cells.
• To address controversies surrounding DNT cell identity and function.
• To identify potential transcriptional signatures for DNT cell subsets.

Main Methods:

• Single-cell RNA sequencing of 28,835 immune cells from C57BL/6 mouse splenocytes.
• Strict fluorescence-activated cell sorting for precise cell isolation.
• Replication of data in a subsequent study.

Main Results:

• Identification of five transcriptionally distinct naïve DNT cell clusters with unique gene expression profiles.
• DNT cells exhibit T helper, cytotoxic, and innate immune functions, enhanced by anti-CD3/CD28 activation.
• High expression of Ikzf2 in both naïve and activated cytotoxic DNT cells compared to other T cells and NK cells.

Conclusions:

• Provides a comprehensive map of naïve and active DNT cell heterogeneity and transcriptional signatures.
• Characterizes functional DNT subsets (helper, cytotoxic, innate), aiding understanding of autoimmune diseases and transplant rejection.
• Facilitates future research on DNT cells in immune homeostasis and disease by establishing a standardized approach.