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Mast cells mediate acute inflammatory responses to implanted biomaterials
L Tang1, T A Jennings, J W Eaton
1Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. ltang@neo.bcm.tmc.edu
Summary
Mast cells and histamine are crucial for initiating the inflammatory response to implanted biomaterials. Blocking histamine receptors or removing mast cells significantly reduces immune cell recruitment to implants.
Area of Science:
- Biomaterials Science
- Immunology
- Inflammation Research
Background:
- Implanted biomaterials provoke acute and chronic inflammatory responses.
- Phagocyte transmigration, chemotaxis, and adhesion are key to acute inflammation.
- Previous research identified chemokines and integrins in chemotaxis and adhesion, but initial transmigration remains unclear.
Purpose of the Study:
- To investigate the role of histamine and mast cells in phagocyte recruitment to biomaterial implants.
- To understand the initial trigger for phagocyte transmigration across the endothelial barrier.
Main Methods:
- Utilized polyethylene terephthalate (PET) disk implants in mice (intraperitoneal and subcutaneous).
- Administered histamine receptor antagonists (H1 and H2 blockers).
- Employed congenitally mast cell-deficient mice and mast cell reconstitution models.
Main Results:
- Mast cell degranulation and histamine release were observed near short-term implants.
- Histamine receptor blockade significantly reduced neutrophil and monocyte/macrophage recruitment (<20% and <30% of control, respectively).
- Mast cell-deficient mice showed markedly reduced phagocyte accumulation on implants, which was restored upon reconstitution.
Conclusions:
- Mast cells and their products, particularly histamine, play a critical role in the initial recruitment of inflammatory cells to biomaterial implants.
- Understanding these mechanisms allows for targeted modulation of acute and chronic inflammation associated with biomaterials.