A new tolerogenic cell RORs onto the scene.

Area of Science:

• Immunology
• Microbiome research
• Cellular differentiation

Background:

• Regulatory T cells (Tregs) are crucial for maintaining gut homeostasis and preventing autoimmune responses.
• Antigen-presenting cells (APCs) play a vital role in initiating adaptive immune responses, including Treg differentiation.
• The specific signals driving the differentiation of microbe-specific Tregs in the gut remain incompletely understood.

Purpose of the Study:

• To investigate the role of RORγt-expressing antigen-presenting cells in directing the differentiation of gut microbe-specific regulatory T cells.

Main Methods:

• Utilized mouse models with specific genetic modifications to track and manipulate RORγt+ APCs.
• Employed single-cell RNA sequencing and flow cytometry to analyze immune cell populations and gene expression.
• Performed in vivo experiments to assess the impact of RORγt+ APCs on Treg differentiation and function in response to gut microbes.

Main Results:

• Identified a distinct subset of RORγt+ antigen-presenting cells in the gut lamina propria.
• Demonstrated that these RORγt+ APCs are essential for the in vivo differentiation of microbe-specific regulatory T cells.
• Showcased that RORγt+ APCs directly influence the gut microbiome-specific immune tolerance.

Conclusions:

• RORγt-expressing antigen-presenting cells are key orchestrators of gut-specific T regulatory cell differentiation.
• This mechanism highlights a critical pathway for maintaining immune balance within the gut microbiome.
• Targeting RORγt+ APCs may offer therapeutic strategies for immune-mediated gut disorders.