The establishment of human T cell lines reactive with specific periodontal bacteria.

Human T cell lines (TCLs) were obtained by stimulation of peripheral blood mononuclear cells (PBMCs) with the 2 periodontopathic bacteria, Porphyromonas gingivalis FDC-381 and Fusobacterium nucleatum FDC-263. After the first round of stimulation and rest, the cells responded specifically to the bacteria originally used to establish each line. Throughout the culture period, the responsiveness of each of the TCLs to their specific bacteria increased. Phenotypic analysis of the TCLs revealed heterogeneity of cell types. In both TCLs approximately 80% of the cells were T cells, all of which bore the alpha beta T cell receptor. The P. gingivalis-reactive TCL (PG-TCL) showed approximately equal proportions of CD4+ and CD8+ cells, whereas the F. nucleatum-reactive TCL (FN-TCL) was predominantly CD4+. The expression of CD25, HLA-DR, CD45RA and CD29 on these CD4+ cells varied throughout the culture period of 45 days. These results demonstrate that it is possible to establish long-term T cell lines reacting to specific periodontopathic bacteria.