染料法实时荧光聚合酶链反应检测人外周血αβT淋巴细胞克隆的条件优化及初步应用

Optimization and application of dye real-time fluorescent polymerase chain reaction for detecting αβT lymphocyte clones in human peripheral blood

目的 探讨实时荧光PCR检测人外周血αβT淋巴细胞克隆性扩增的反应条件及在监测慢性乙型肝炎（慢乙肝）患者外周血克隆特异性T淋巴细胞上的初步应用.方法 染料法（SYBR Green Ⅰ）实时荧光PCR对6例健康献血者外周血单个核细胞（PBMC）来源的T淋巴细胞受体β链可变区（TCRBV）基因进行扩增,分别就退火温度、引物浓度、循环数等进行比较研究.优化后PCR检测12例慢乙肝患者PBMC来源的TCRBV的24个基因家族,作PCR产物的熔解曲线峰形图,并分析T淋巴细胞克隆性扩增情况.结果 染料法实时荧光PCR检测 TCRBV基因家族的最佳退火温度为60.6℃,引物终浓度为0.5 μmol/L,循环数为40个,且熔解曲线分析起始温度80℃优于75℃.PCR产物熔解曲线峰形图上发现,慢乙肝患者某些TCRBV基因家族表现为单峰,测序结果表明其为单克隆PCR产物.结论 本研究优化了染料法实时荧光PCR检测TCRBV基因家族方法,熔解曲线峰形图可用于检测人外周血T淋巴细胞的克隆性扩增,并可能用于检测慢乙肝患者外周血克隆特异性T淋巴细胞.

Abstract：Objective To investigate the optimized parameters of dye （SYBR Green Ⅰ） realtime fluorescent polymerase chain reaction （RF-PCR） for detecting αβT lymphocyte clones in the peripheral blood and its application in monitoring specific T cell clone in the peripheral blood mononuclear cells （PBMC） from patients with chronic hepatitis B （CHB）. Methods The total RNA was extracted from the PBMC of six healthy donors, and was reversely transcripted into cDNA. Then the cDNA was amplified using RF-PCR with the primers specific for T cell receptor β viable region （TCRBV） gene families as upstream primers and the primer for T cell receptor （TCR） β constant region （TCRBC） as downstream primer. The annealing temperature,concentration of primers and the total number of cycles were comparatively analyzed. The optimized PCR was performed to investigate the 24 TCRBV gene families from 12 patients with CHB, and the PCR products were monitored by melting curve analysis, and the clone expansion of peripheral blood T cell was detected by peak-motif of melting curve analysis. Results The optimized annealing temperature, final premier concentration,the number of cycles were 60.6 ℃, 0.5 μmol/L and 40 cycles, respectively. The begin temperature for melting curve analysis was better as 80 ℃ compared to 75 ℃. There was mono-peak on melting peak chart for TCRBV gene families in PBMC from patients with CHB, and PCR products of the single peak were determined as monoclonal T cell by sequencing. Conclusions The optimized reaction parameters of RF-PCR for monitoring 24 TCRBV gene families are determined. The melting peak chart could be used to monitor the clone expansion of the peripheral lymphocytes and to detect the clone-specific T cells in the peripheral blood from patients with CHB.