RelB and C/EBPα critically regulate the development of Peyer's patch mononuclear phagocytes

Area of Science:

• Immunology
• Gastroenterology
• Cell Biology

Background:

• Peyer's patches (PPs) in the small intestine are crucial for immune surveillance against foreign antigens.
• Sub-epithelial dome (SED) mononuclear phagocytes (MPs) within PPs play a key role in initiating T cell responses.
• The regulatory mechanisms governing SED-MP functions remain largely unknown.

Purpose of the Study:

• To identify key transcription factors regulating the unique functions of SED-MPs.
• To elucidate the roles of RelB and C/EBPα in SED-MP-mediated mucosal immunity.

Main Methods:

• Transcriptome analysis of SED-MPs to identify gene signatures.
• Transcription factor (TF) enrichment analysis to predict regulatory TFs.
• Investigating the effects of RelB and C/EBPα deficiency on SED-MP function and bacterial invasion.

Main Results:

• RelB and C/EBPα were identified as preferentially activated TFs in SED-MPs.
• RelB deficiency led to reduced expression of IL-22BP and S100A4 by SED-MPs.
• C/EBPα deficiency impaired lysozyme expression, increasing pathogenic bacterial invasion into PPs and lymph nodes.

Conclusions:

• RelB and C/EBPα are essential transcription factors that regulate critical functions of SED-MPs.
• These factors are vital for maintaining mucosal immune homeostasis and preventing bacterial translocation.