Investigating Adhesion Molecules in Stem Cell - Immune Cell Interactions Using Organoids.

Area of Science:

• Dental research
• Tissue engineering
• Immunology

Background:

• Immune cell-mesenchymal stem cell interactions are crucial for tissue repair and regeneration.
• Direct cell-to-cell contact is essential for this crosstalk.
• Apical periodontitis involves complex interactions within the immature permanent tooth.

Purpose of the Study:

• To investigate direct cell-to-cell interactions between stem cells from apical papilla (SCAP) and macrophages (MQ).
• To understand the role of specific adhesion molecules in these interactions within an organoid model.
• To explore the impact of inflammatory stimuli on SCAP-MQ communication relevant to apical periodontitis.

Main Methods:

• Comparison of 2D SCAP-MQ co-cultures with 3D self-assembled tissue constructs.
• Exposure to non-stimulated, lipopolysaccharide (LPS), or interleukin (IL)-4 conditions for up to 7 days.
• Assessment of adhesion molecule expression (CD200, CD200 R, ICAM-1, N-cadherin, LFA-1) via qPCR and confocal microscopy.

Main Results:

• LPS stimulation decreased CD200 and CD200 R immunofluorescence.
• N-cadherin gene expression increased in 3D constructs under LPS.
• ICAM-1 expression rose with LPS in 2D cultures, while IL-4 showed varied effects on other molecules.

Conclusions:

• Extracellular collagen and inflammation significantly alter adhesion molecule expression in SCAP-MQ co-cultures.
• LPS and IL-4 differentially modulate key adhesion molecules, impacting SCAP-MQ interactions.
• 3D organoid models effectively simulate these interactions, providing a basis for future regenerative therapies for dental pulp.