What we know about the cellular microenvironment of clinically healthy human gingiva? An immunohistochemical and histological study

Abstract

AbstractThe present study deals with histological descriptions of clinically healthy human gingivae through the methods of light, electron microscopy and immunohistochemistry. Even clinically healthy human gingivae are subject to constant bacterial and mechanical influences present in the oral cavity; therefore, the term “normal gingiva” is misleading. The aim of this study was to identify, in clinically healthy gingiva, all active cells through immunohistochemical markers and light and electron microscope examination. In tissue samples from clinically healthy gingivae of nine patients, we observed the presence of different cells (e.g., T- and B-lymphocytes, macrophages, Merkel cells, Langerhans cells, proliferating cells) and some components of their extracellular matrix that use antibodies against S-100 protein, CD68, CD20, CD45RO, CD20, and Ki67. The presence of immunologically active cells and the ultrastructural characteristics of gingivae were also confirmed. The stratified squamous epithelium of human gingiva contains a population of Langerhans cells and intraepithelial Tlymphocytes. The underlying dense connective tissue contains primarily fibroblasts, but also T-lymphocytes, occasionally B-lymphocytes, plasma cells, and macrophages can be seen. As a border between the oral cavity and the internal environment of the human body, the gingivae are an important part of the immune system. Such findings show that, in healthy gingival tissue, there are constantly ongoing anti-inflammatory, immunological, and regenerative reactions and processes.