Inflammatory cells extracted from chronically inflamed gingiva

Abstract

A method is described for separating and identifying a viable fraction of the cellular infiltrate released from specimens of inflamed gingiva by enzyme digestion. Gingiva was surgically removed from 6 patients undergoing treatment for periodontal disease. Cells released into suspension after 30, 60 and 90 minutes' incubatio with collagenase and hyaluronidase were analysed. The T lymphocyte population in the cell suspension was assayed by rosette formation with sheep erythrocytes (E) treated with S‐2 Amino ethylisothiouronium bromide (E‐AET). Complement receptor bearing cells (B lymphocytes and macrophages) were enumerated by rosette formation with sheep erythrocytes sensitized with IgM antibody (A) and complement (EAC). Macrophages were identified histochemically by their non‐specific esterase content. The average total yield of nucleated cells extracted was approximately 1X106 per 100 mg. of gingiva. The number of contaminating erythrocytes was highest at 30 minutes. At 60 minutes' incubation there was an increase in the number of contaminating epithelial cells released into suspension. The viability of extracte cells consistently exceeded 90% in the 30 and 60 minute fractions as measured by dye exclusion but fell to between 80 and 85% after 90 minutes. The proportions of T lymphocytes found in each fraction were 81%, 72% and 64% respectively. Most of the complement receptor bearing cells were found to be macrophages, and only small numbers of B lymphocytes were identified.