In the oral cavity, the immune system is constantly exposed to unique tissue-specific signals, including a rich community of commensal microbes and their metabolites, continuous tissue damage from mastication, and antigens from food and airborne particles. How this unique combination of signals participates in the training of specialized immunity at this site is not well understood, yet imbalance of local responses is linked to tissue-specific disease susceptibilities with the prototypic disease being periodontitis. However, the oral mucosa is also well recognized as a site where systemic inflammatory and autoimmune diseases often manifest, indicating that systemic immune deregulation is reflected in the function of the oral immune system. This commentary will discuss both aspects of compartmentalized and systemic immunity at the oral mucosa.

This article discusses the proceedings of the conference organized by the Task Force on Design and Analysis in Oral Health Research on the new advances in host-microbiome interactions, analytical methods, and their implication in inflammatory periodontal disease management.

Hair follicle-associated-pluripotent (HAP) stem cells are located in the bulge area of the hair follicle, express the stem-cell marker nestin, and have been shown to differentiate to neurons, glial cells, keratinocytes, smooth muscle cells, melanocytes and cardiac muscle cells. Transplanted HAP stem cells promoted the recovery of peripheral nerve and spinal cord injuries and have the potential for heart regeneration as well. In the present study, we implanted mouse green fluorescent protein (GFP)-expressing HAP stem-cell spheres captured on polyvinylidene fluoride membranes (PFM) into the severed thoracic spinal cord. of nude mice. Eight weeks after implantation, immunofluorescence staining showed that HAP stem cells differentiated into neurons and glial cells. Fluorescence microscopy showed that the PFMcaptured HAP stem-cell hair spheres promoted rejoining of the thoracic spinal cord of the nude mice. Hematoxylin and eosin (H&E) staining also showed that the severed thoracic spinal cord had rejoined. Quantitative walking analysis showed a significant difference between the implanted mice and non-implanted mice with a several spinal cord. HAP stem cells are readily accessible from everyone, do not form tumors, and can be cryopreserved without loss of differentiation potential. These results suggest that HAP stem cells may have greater potential than iPS or ES cells for regenerative medicine, such as for spinal cord repair.