Diminished immunoglobulin synthesis after stimulation of mononuclear cells from periodontal disease tissue.

Gingival mononuclear cells from patients with adult periodontitis were cultured to determine the potential for IgG production. All samples (N = 27) showed IgG synthesis. Some samples demonstrated IgG synthetic activity over the entire period in culture, often with maximum synthesis after 8 days. Other samples showed IgG synthesis during the first half of the culture period and then little detectable production for the remainder. Cells were either untreated or treated with one of several different known mitogens during the culture period. Total IgG synthesis by peripheral blood lymphocytes was enhanced in the presence of pokeweed mitogen, E. coli lipopolysaccharide and killed. A. actinomycetemcomitans. In contrast, IgG synthesis by gingival cells in the presence of these same additives was significantly reduced when compared to gingival cell synthesis in the absence of mitogens; suggesting the presence of suppression in this system. These differences in responsiveness may be attributable to the unique combination of T cells found in the gingival tissues of patients with periodontal diseases. The patterns of IgG synthesis by gingival cells were different from those of peripheral blood cells from the same patient. This finding verified the distinctiveness of local immunoregulatory mechanisms in periodontal disease tissue from those found systemically.