LOCALIZATION AND ANTIGEN-SPECIFICITY OF PLASMA CELLS IN PERIODONTITIS LESIONS

Abstract

Periodontitis is characterized by large infiltration of B cells and plasma cells. In this study, CD19+CD27+CD38+HLA-DRlow as periodontitis tissue–plasma cells were identified by flow cytometry. And these cells were also CD138+ (a plasma cell marker). In severe periodontitis lesions, large number of CD138+ plasma cells which form small clusters disseminated in connective tissue were consistently demonstrated by immunostaining. The densest area of co-localization of CD138+ plasma cells and CD3+ T cells were at the base of pocket epithelium. But none or very few CD138+ plasma cells was/were observed in clinically healthy gingiva. From ELISPOT assay, we detected Ig-producing plasma cells specific to a key periodontal pathogen, Porphyromonas gingivalis and to a lesser extent against Aggregatibacter actinomycetemcomitans. Total IgG spot forming cells (SFC) were significant higher than total IgA SFC. On the other hand, Ig specific for commensal plaque bacteria-Streptococcus gordonii or self-tissue collagen could not be detected. More studies are required to gain insight into the role of periodontal tissue-plasma cells in protection or pathogenesis of the disease.