The role of TG lymphocytes in cell-mediated immunity in patients with periodontal disease.

Blood mononuclear cell suspensions from patients with a severe form of periodontal disease failed to respond by in vitro stimulation to a sonicate from the oral bacterium, Veillonella alcalescens. The proliferative response could be restored by the depletion of TG cells by rosetting with IgG-coated ox erythrocytes and by reconstitution of the cell suspension with 10% plastic-adherent monocytes. Small but statistically significant restoration of the Veillonella response was also achieved by the addition of indomethacin or mefenamic acid to unfractionated cell cultures, indicating only a minor role of prostaglandin (PG) synthesis in the expression of suppressor cells. Since the in vitro response to an unrelated antigen PPD had been found unimpaired, the described TG-cell-mediated suppression of the Veillonella response is apparently antigen-specific.