Fine structure of healthy human gingival mast cells and their immunological characterization

Despite the great number of studies on mast cell population, at the present time few are the studies regarding the structural aspects of mast cells in human gingiva. In order to identify and characterize gingival mast cells, specimens of healthy human gingival tissue have been studied. Subsequently, in order to test mast cell capability of express TNF-alfa, samples of healthy gingiva with antibody anti-TNF-alfa have been incubated. The results showed that in human gingiva mast cells are numerous and ubiquitarious. These cells exhibit several morphological types of cytoplasmic granules with characteristic subgranular content, varying in shape and density. This allows to divide gingival mast cells into two different subpopulations: either cells containing granules with compact coiled scrolls and/or particles and cells showing granules with scrolls and thin parallel bands. The two ultrastructural aspects observed seem to be correlated to the McT (mast cells containing tryptase) and McTC (mast cells containing tryptase and chymase) described in international literature, differing for ultrastructural aspect, biochemical content and response to secretagogue substances. The positivity of the reaction for TNF-alfa seems indeed to confirm that gingival mast cells are able to secrete sensible amounts of TNF-alfa.