Immunomodulatory Properties of Miniature Pig Periodontal Ligament Stem Cells

Objectives: Periodontal disease (PD) remains a major public health problem. Chronic unresolved inflammation associated with proinflammatory oral microbiome dysbiosis creates host-mediated destruction of the periodontium. Resolution of inflammation is an active, receptor mediated process initiated by Specialized Proresolving lipid Mediators (SPMs). SPMs activate wound healing with tissue regeneration of hard and soft tissues lost to periodontitis in several animal models, including the miniature pig. Human periodontal ligament stem cells (PDLSCs) release SPMs; however, characterizing the biomimetic properties of stem cells in humans is hampered by a lack of suitable large animal models. Therefore, there is a critical need for a validated large animal regeneration model to test therapeutic potential of stem cells for translation to humans. The objective of this study was to isolate and characterize PDLSCs from the miniature pig.
Methods: The incisors and cuspids of 6-month old Yorkshire miniature pigs were extracted, PDLSCs were isolated and cultured. Flow cytometric analysis identified stem cell surface markers using anti-pig antibodies to CD105, CD90, CD45 and CD11b. Lipid Mediator Metabololipidomics was performed by mass spectroscopy LC-MS/MS.
Results: Miniature pig PDLSCs express stem cell surface markers CD90 and CD105, and lack expression of CD45 and CD11b, similar to human PDLSCs. They biosynthesize SPMs including resolvins, maresins and both 17-HDHA and 14-HDHA lipoxygenase-pathway markers as well as PGE2 via cyclooxygenase identified used LC-MS-MS based profiling.
Conclusions: Miniature pig PDLSCs have the same surface marker profile and a similar SPM profile to the recently published human PDLSC LM-SPM profile. These results will allow further development and characterization of a large animal model to test novel stem cell-based strategies for translation to human oral and craniofacial tissue regeneration. The goal is to develop therapies using PDLSCs and proresolving mediators to optimize endogenous tissue microenvironments and tissue responses to enhance tissue healing and regeneration.