Cytokine profiles of T-lymphocytes from gingival tissues with pathologicalpocketing

Periodontal disease is an infection in which destruction occurs at sites re mote from the infection, resulting in pathological pocketing. Intervening b etween the infection and the destruction is a dense mononuclear inflammator y infiltrate. It has been suggested that this infiltrate might have charact eristics and the destructive potential of Th1-type T lymphocytes. To ascert ain the nature of the infiltrates we investigated the expression of mRNA fo r IL-2, IL-5, and IFN-gamma by gingival mononuclear cells (GMC) from health y (n = 8) or adult periodontitis (AP) patients (n = 25) by using cytokine-s pecific reverse-transcription/polymerase-L chain-reaction (RT-PCR). GMC, as obtained from patients' tissues, expressed IL-2, IFN-gamma, or IL-5 mRNA. Significantly higher proportions of GMC from AP patients expressed IL-2 and IFN-gamma mRNA than did those from healthy subjects. IFN-gamma was the mos t consistent cytokine message detected. In other experiments, gingival T-ly mphocytes (n = 12) and CD4(+) and CD8(+) gingival T-lymphocytes (n = 16) we re isolated from gingival tissues removed surgically from AP patients. AP g ingival T-lymphocytes expressed mRNA for IL-2, IFN-gamma, or IL-6 prior to stimulation. After stimulation with Con A, the cells significantly up-regul ated IL-5 and IL-6 message expression. Both CD4(+) and CD8(+) gingival T-ly mphocytes expressed IFN-gamma, IL-5, and some IL-2. This cumulative cytokin e profile observed in these experiments is consistent with the predominance of Th1-type cells in pathological tissues and with Th2-type cells, which c an also be present, being up-regulated under appropriate stimulation. Impor tantly, CD4(+) and CD8(+) lymphocytes were shown to express T1- and T2-type cytokine message, emphasizing the potential for CD8(+) T-lymphocytes to pa rticipate in periodontal disease pathology.