Celiac Disease Monocytes Induce a Barrier Defect in Intestinal Epithelial Cells

Area of Science:

• Immunology
• Gastroenterology
• Cell Biology

Background:

• Intestinal epithelial barrier dysfunction is a hallmark of celiac disease (CeD).
• The precise mechanisms driving this barrier defect, particularly the role of immune cells, remain incompletely understood.

Purpose of the Study:

• To investigate the contribution of peripheral monocytes to intestinal epithelial barrier impairment in celiac disease.
• To characterize the functional and molecular differences of monocytes from active and inactive CeD patients compared to healthy controls.

Main Methods:

• Isolation of human monocytes from peripheral blood mononuclear cells (PBMCs) of CeD patients and healthy controls.
• Co-culture of monocytes with intestinal epithelial cells (IECs) and assessment of barrier function via transepithelial electrical resistance (TEER).
• Analysis of tight junction proteins (ZO-1, occludin, claudin-5) and cytokine profiles (IL-6, MCP-1) in monocytes.

Main Results:

• IECs exposed to monocytes from celiac disease patients showed significantly decreased transepithelial resistance.
• Confocal microscopy and Western blotting confirmed alterations in tight junction proteins (ZO-1, occludin, claudin-5) in affected IECs.
• Celiac monocytes exhibited higher levels of pro-inflammatory cytokines, including interleukin-6 and MCP-1, compared to controls.

Conclusions:

• Peripheral monocytes in celiac disease possess an intrinsic pro-inflammatory cytokine pattern.
• These monocytes have the capacity to compromise intestinal epithelial barrier function by modulating tight junction composition.