IADR Abstract Archives
Incorporating Macrophages Into Tissue-Engineered Oral Mucosal Equivalents Improves Inflammatory Response.
Objectives: Macrophages play a key role in the detection and phagocytosis of invading organisms or foreign molecules and help orchestrate an inflammatory immune response within oral tissues. This study aimed to develop a tissue-engineered model of buccal oral mucosa containing primary macrophages to better model the immune response in this tissue.
Methods: Primary human monocyte-derived macrophages (MDM) isolated from blood were incorporated into a type 1 collagen hydrogel alongside oral fibroblasts. The apical surface was seeded with immortalised (FNB6) oral keratinocytes and then cultured at an air-to-liquid interface for 10 days to generate an MDM-oral mucosal equivalent (OME). Model histology and cell viability were assessed, then MDM-OME challenged with E. coli lipopolysaccharide (LPS) ± dexamethasone to examine changes in inflammatory gene expression and secretion of the proinflammatory cytokines TNF-α, CXCL8 and IL-6.
Results: Addition of MDM into an OME had no effect on tissue structure and MDM within the OME were immune-positive for macrophage-specific marker CD68. CD11c-positive MDM isolated from models by collagenase treatment were 68% viable when analysed by flow cytometry. MDM-OME responded to LPS with increased gene expression of CXCL8 and IL-6 that was inhibited by dexamethasone when compared to OME. Secretion of TNF-α was increased 10-fold in LPS treated MDM-OME compared to all other conditions, while CXCL8 expression was increased by LPS compared to all OME regardless of treatment.
Conclusions: MDM-OME responded to inflammatory stimuli by shifting to a pro-inflammatory phenotype which could be dampened by treatment with a clinically used anti-inflammatory steroid. In future studies MDM-OME can be used to provide an improved platform to test immune responses against infectious agents and biomaterials and to examine anti-inflammatory drug efficacy.
Methods: Primary human monocyte-derived macrophages (MDM) isolated from blood were incorporated into a type 1 collagen hydrogel alongside oral fibroblasts. The apical surface was seeded with immortalised (FNB6) oral keratinocytes and then cultured at an air-to-liquid interface for 10 days to generate an MDM-oral mucosal equivalent (OME). Model histology and cell viability were assessed, then MDM-OME challenged with E. coli lipopolysaccharide (LPS) ± dexamethasone to examine changes in inflammatory gene expression and secretion of the proinflammatory cytokines TNF-α, CXCL8 and IL-6.
Results: Addition of MDM into an OME had no effect on tissue structure and MDM within the OME were immune-positive for macrophage-specific marker CD68. CD11c-positive MDM isolated from models by collagenase treatment were 68% viable when analysed by flow cytometry. MDM-OME responded to LPS with increased gene expression of CXCL8 and IL-6 that was inhibited by dexamethasone when compared to OME. Secretion of TNF-α was increased 10-fold in LPS treated MDM-OME compared to all other conditions, while CXCL8 expression was increased by LPS compared to all OME regardless of treatment.
Conclusions: MDM-OME responded to inflammatory stimuli by shifting to a pro-inflammatory phenotype which could be dampened by treatment with a clinically used anti-inflammatory steroid. In future studies MDM-OME can be used to provide an improved platform to test immune responses against infectious agents and biomaterials and to examine anti-inflammatory drug efficacy.