Characteristic T cell receptor repertoire and cytokine profile of infiltrating T cells in chronic inflammatory periodontal disease

为了解牙周炎患者牙周组织中T细胞的分布特征，我们分别采用RT-PCR和RT-PCR-SSCP方法分析了牙周炎患者牙周组织中T细胞的细胞因子mRNAs的表达和克隆性。此外，还研究了牙周病原菌P.givalis对外周血T细胞克隆性变化的刺激作用。结果表明，干扰素-γ在PBMC中的平均表达水平显著高于牙周组织。IL-10mRNA在牙周组织中的平均表达水平高于外周血单个核细胞，而IL-10mRNA的高表达仅见于7例牙周组织标本中，且大多数标本的表达水平与外周血单个核细胞相似。SSCP分析显示，IL-13在牙周组织和PBMC中的平均表达无差异，PBMC中的条带较少，但组织样本中大多数Vbeta家族的条带较多。SSCP凝胶上的一条带表明TCR的CDR3区有一个核苷酸序列均一的T细胞克隆。模拟实验表明，刺激后出现了几条新的明显条带，表明明显的克隆性积累，尽管大多数情况下不同条带的数量减少了。这些结果表明，具有2型细胞因子特征的T细胞克隆正在发病部位扩增或聚集。

In order to characterize the T cells infiltrating into gingival tissue of periodontitis patients, we analyzed the expression of cytokine mRNAs and clonality of those T cells by using RT-PCR and RT-PCR-SSCP,respectively. Further, the stimulatory effects of P.gingivalis, a periodontopathic bacteria, on the change of peripheral blood T cell clonality was also investigated. The results demonstrated that the mean expression of IFN-y mRNA was significantly higher in PBMC than in gingival tissues. In contrast, the mean expression of IL-10mRNA was higher in gingival tissues than in PBMC.This high expression of IL-10mRNA was in fact, seen in only 7 gingival tissue samples with the majority of samples showing levels similar to PBMC.There was no difference in the mean expression of IL-12p35 mRNA between gingival tissues and PBMC.However, IL-12p40 mRNA was expressed higher in gingival tissues than in PBMC in 6 out of 16 samples with significant difference of mean expression. There was no dofference in the mean expression of IL-13 in gingival tissues and PBMC.SSCP analysis showed smear patterns with few bands in PBMC,but a number of bands in most Vbeta families in tissue samples. A band on the SSCP gel indicate a T cell clone with homogeneous nucleotide sequence in the CDR3 region of the TCR.Simulation experiment demonstrated that several new distinct bands appeared after stimulation, indicating distinct clonal accumulations, although the number of distinct bands decreased in most cases. These data suggest that clonolypic change occurred following stimulation with P.gingivalis OM.These results suggest that T cell clones with type 2 cytokine profile are expanding or accumulating at the site of disease.