A TNF-IL-1 circuit controls Yersinia within intestinal pyogranulomas

Area of Science:

• Immunology
• Microbiology
• Cell Biology

Background:

• Tumor necrosis factor (TNF) is a key inflammatory cytokine involved in host defense against pathogens.
• Yersinia pseudotuberculosis infection leads to pyogranuloma formation in the intestine, requiring inflammatory monocytes for control.
• The precise mechanisms by which monocytes restrict Yersinia infection within pyogranulomas are not fully understood.

Purpose of the Study:

• To investigate the role of TNF signaling in monocyte-mediated control of intestinal Yersinia infection.
• To elucidate the molecular pathways by which monocytes restrict bacterial growth within pyogranulomas.

Main Methods:

• Utilized mouse models of enteric Yersinia pseudotuberculosis infection.
• Analyzed the requirement of TNF signaling in monocytes using genetic approaches.
• Investigated the role of monocyte-derived IL-1 and its receptor signaling on non-hematopoietic cells.

Main Results:

• TNF signaling specifically within monocytes is essential for containing Yersinia infection in the intestine.
• Monocyte-intrinsic TNFR1 signaling is required for the production of IL-1.
• Monocyte-derived IL-1 acts on non-hematopoietic cells to facilitate pyogranuloma-mediated bacterial control.

Conclusions:

• A novel monocyte-intrinsic inflammatory circuit involving TNF and IL-1 is critical for restricting intestinal Yersinia infection.
• This TNF-IL-1 axis highlights a collaborative inflammatory mechanism for host defense against enteric pathogens.