Distribution and organization of lymphatic vessels in the mouse gingiva: An immunohistochemical study with LYVE-1

Abstract

Objective This study introduced the usefulness of LYVE-1 immunoreactivity for identification of lymphatic vessels in decalcified tissues, and demonstrated the fine distribution and organization of these vessels in mouse gingiva. Design After confirming the specificity of anti-mouse LYVE-1, frozen sections of mouse decalcified gingiva were immunostained with the antibody. Results The LYVE-1-positive lymphatic vessels were clearly found in the connective tissue under the gingival epithelium; these vessels appeared to pass through the lamina propria of the gingiva toward the alveolar crest and run along the external surface of the alveolar bone. The lymphatic vessels were sparse and apart from the oral gingival and sulcular epithelia, while they were dense adjacent to the junctional epithelium. Conclusions The dense network of the lymphatic vessels adjacent to the junctional epithelium, which is apparently exposed to foreign antigens, may act as an efficient drainage pathway of the excessive interstitial fluid and immune cells, and play an active role in the immune defense of the gingiva. The present study also revealed the absence of lymphatic connection between gingiva and periodontal ligament.