The proportion of interleukin-4, interferon-gamma and interleukin-10-positive cells in Porphyromonas gingivalis-specific T-cell lines established from P-gingivalis-positive subjects

T-cell cytokine profiles in ten adult periodontitis and seven age-matched h ealthy or gingivitis subjects were determined. Porphyromonas gingivalis-spe cific T-cell lines were established from the peripheral blood of these indi viduals all of whom had past or present evidence of P. gingivalis infection . FACS analysis was used to determine the percentage of CD4- and CD8-positi ve cells in each line staining for cytoplasmic interleukin (IL)-4, interfer on-gamma and IL-10. There were no differences in the mean percentage of IL- 4-, interferon-gamma- or IL-10-positive T cells between the two groups. How ever, the individual profiles showed that the CD4 cells in five of the seve n healthy or gingivitis lines had a higher proportion of interferon-gamma-p ositive cells, with two lines demonstrating higher percentages of IL-10- an d/or IL-4-positive CD4 cells. Five of the ten adult periodontitis lines dem onstrated either equal or higher percentages of IL-4-positive and/or IL-10- positive CD4 cells. With respect to the CD8 cells, two of the seven lines e stablished from the healthy or gingivitis subjects and six of the ten adult periodontitis lines showed profiles with a higher percentage IL-4- and/or IL-10-positive cells. When the total T-cell contribution (CD4 plus CD8) for each T-cell line was determined from the individual CD4:CD8 ratios, only o ne of the healthy or gingivitis lines showed a profile with a higher propor tion of IL-10-positive cells, while the results for the adult periodontitis lines were the same as indicated for the CD4 cell profiles, with five line s showing a higher percentage of IL-4- and/or IL-10-positive cells. In conc lusion, this study has shown that in P. gingivalis-responsive T-cell lines established from adult periodontitis and healthy or gingivitis subjects, th ere was a predominant trend towards a higher percentage of interferon-gamma positive cells than either IL-4- or IL-10-positive cells. However, there w ere variations from this trend, although whether these variations indicate true susceptibility to progressive disease has yet to be determined.