change in frequency of Regulatory T cells in peripheral blood from Patients with Oral Squamous Cell Carcinomas

• Main Authors: Hui-Hsin Ko, 柯惠馨
• Other Authors: Jean-San Chia
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/88077872926971775016

碩士 === 國立臺灣大學 === 臨床牙醫學研究所 === 96 === Oral squamous cell carcinoma (OSCC) accounts for more than 95% of all malignant neoplasms in the oral cavity, and ranks as the sixth major cause of cancer mortality in Taiwan. Here, OSCC is associated with the areca nut chewing and characterized by an unsatisfactory 5-year survival rate after treatment. Emerging evidence suggested that head and neck carcinoma exhibits multiple immunosuppressive characteristics, but whether OSCC displays similar phenomenon is still not clear. In the present study, the distribution of CD4+CD25+ regulatory T cells (Treg) in the peripheral blood before or after treatment and the change in ratio or iNKR markers of CD8+T lymphocytes were investigated. we also examined the expression of various on T lymphocytes (especially). A total of 30 OSCC patients (TNM Stage I to IV) and 20 aged-match healthy donors were enrolled and their peripheral blood mononuclear cells (PBMCs) were analyzed by triple-color and quadruple flow cytometry using a panel of specific monoclonal antibodies. Patients with OSCC had significantly higher CD4+/CD8+ ratio than normal controls attributable to a decrease in CD8+ T cells. Among the CD3+CD4+ subsets, CD25+ Treg represented 5.86±5.23 % in OSCC patients or 1.68±0.95 % in normal controls (p < 0.001). Furthermore, Mean percentage of CD4+CD25high Treg, which exhibited higher mean flurescence intensity of CD25+ expression, of OSCC patients (1.84±1.74%) is also significantly higher than in healthy donors (0.43±0.40 %, p< 0.005). Identity of Treg in both CD4+CD25high or CD4+CD25low subsets were confirmed by a positive intra-cellular staining of Foxp3+, an important transcription factor and the most specific molecular marker for regulatory T cells. The increase in CD25high Treg was related to TNM stage, but not site of cancer occurrence. After treatment, the percentage of CD4+CD25+ Treg in the OSCC patients decreased significantly (2.87±2.69 %, p<0.05) to the level comparable to (before) normal controls. There was no significant difference in the expression of iNKRs, NKG2A or NKG2D, on circulating CD8+ T cells from OSCC patients compared to normal controls. But the increased CD4+/CD8+ ratio or the decreased CD8 number in OSCC patients converted to normal level after treatment. These results suggested that the frequency of circulating Treg correlated directly with the severity of disease and the decreased circulating CD8+ count in OSCC patients, and conversion of circulating Treg might reflect efficacy of cancer treatment.