MicroRNA-142 regulates gut associated lymphoid tissues and group 3 innate lymphoid cells

Area of Science:

• Immunology
• Molecular Biology
• Gastroenterology

Background:

• Innate lymphoid cells (ILCs) are key immune cells in mucosal tissues.
• While transcriptomic regulation of ILCs is known, post-transcriptional control remains unclear.
• MicroRNAs (miRNAs) are critical post-transcriptional regulators in the immune system.

Purpose of the Study:

• To investigate the role of microRNA-142 (miR-142) in the development and function of intestinal ILCs.
• To elucidate the impact of miR-142 on ILC3 subsets and gut-associated lymphoid tissues.
• To identify miR-142 targets and pathways involved in intestinal mucosal immunity.

Main Methods:

• Germline and conditional deletion of the Mir142 gene in mice.
• Analysis of ILC composition and phenotype in the intestinal lamina propria.
• Assessment of gut-associated lymphoid tissue development.
• RNA sequencing (RNAseq) to identify target genes and pathways.
• Evaluation of disease pathology in a colitis model.

Main Results:

• Germline Mir142 deletion led to altered ILC composition, absence of T-bet+ populations, and defective ILC3 subsets (including CCR6+ LTi-like ILC3s).
• Mir142 deficiency resulted in impaired gut-associated lymphoid tissue development, notably the absence of Peyer's patches.
• Conditional deletion in ILC3s confirmed cell-intrinsic roles for miR-142 in ILC3 cellularity and function, with elevated IL-17A production.
• RNAseq identified potential miR-142 target genes and biological pathways.

Conclusions:

• MicroRNA-142 is essential for the development and function of intestinal ILC3s.
• miR-142 plays a critical role in establishing gut-associated lymphoid tissues and maintaining intestinal mucosal immunity.
• These findings highlight miR-142 as a key post-transcriptional regulator in the immune system.