Chen Shaohua, Yang Lijian, Lu Xiaoye, Li Bo, Chan John Yeuk-Hon, Cai Dongqing, Li Yangqiu
Institute of Hematology, Medical College, Jinan University, Guangzhou, China.
Hematology. 2010 Aug;15(4):230-5. doi: 10.1179/102453309X12583347113537.
In order to elucidate the feature of T-cell immune status in umbilical cord blood (CB) from humans, the expression levels of CD3gamma, delta, epsilon, and zeta chain genes in CD4(+) and CD8(+) T cells of CB were analysed by real-time PCR. CD4(+) and CD8(+) T cells sorted from 12 cases of CB and 10 peripheral blood (PB) samples from healthy adults were used in the study. The beta2-microglobulin gene was used as an endogenous reference, and the evaluations of mRNA expression level of each CD3 gene were used by the 2(-DeltaC(t)) x 100% method. In CD4(+) T cells, the expression levels of CD3gamma, delta, and zeta genes (16.54+/-6.49, 3.53+/-1.15, and 5.48+/-1.10%) from CB were significantly higher than those from PB (P=0.001, P=0.017, and P=0.000, respectively). Higher expression levels of CD3delta and zeta genes (3.43+/-1.19 and 5.24+/-1.42%) in CD8(+) T cells from CB were found than those from PB (P=0.000 and P=0.004). Moreover, the expression level of CD3epsilon gene in CD4(+) T cells from CB (13.29+/-5.72%) was significantly different from that in CD8(+) T cells (7.81+/-4.72%, P=0.018). Thus, the expression pattern of four CD3 genes were gamma>epsilon>zeta>delta in both CD4(+) and CD8(+) T cells from CB, while similar expression pattern was found in CD8(+) T cells from PB samples. In contrast, the expression pattern was presented as epsilon>gamma>zeta>delta in CD4(+) T cells from PB. In conclusion, the present study characterized the expression pattern of CD3gamma, delta, epsilon, and zeta chain genes in CD4(+) and CD8(+) T cells from CB, which might be very useful for further understanding the feature of T-cell immune status in umbilical cord blood. Higher expression of CD3 genes in CD4(+) T cells might relate to the strong ability of activation of TCR-mediated signals, and suggests that this is one of the features responsible for the low allo-reactivity of CB T cells.
为阐明人类脐带血（CB）中T细胞免疫状态的特征，采用实时PCR分析了CB中CD4(+)和CD8(+) T细胞中CD3γ、δ、ε和ζ链基因的表达水平。本研究使用了从12例CB和10例健康成人外周血（PB）样本中分选得到的CD4(+)和CD8(+) T细胞。以β2-微球蛋白基因为内参，采用2(-ΔC(t))×100%法评估各CD3基因的mRNA表达水平。在CD4(+) T细胞中，CB中CD3γ、δ和ζ基因的表达水平（分别为16.54±6.49、3.53±1.15和5.48±1.10%）显著高于PB（P分别为0.001、0.017和0.000）。发现CB中CD8(+) T细胞中CD3δ和ζ基因的表达水平（分别为3.43±1.19和5.24±1.42%）高于PB（P分别为0.000和0.004）。此外，CB中CD4(+) T细胞中CD3ε基因的表达水平（13.29±5.72%）与CD8(+) T细胞中（7.81±4.72%）显著不同（P=0.018）。因此，CB中CD4(+)和CD8(+) T细胞中四个CD3基因的表达模式均为γ>ε>ζ>δ，而PB样本中CD8(+) T细胞呈现类似的表达模式。相反，PB中CD4(+) T细胞的表达模式为ε>γ>ζ>δ。总之，本研究确定了CB中CD4(+)和CD8(+) T细胞中CD3γ、δ、ε和ζ链基因的表达模式，这可能有助于进一步了解脐带血中T细胞免疫状态的特征。CD4(+) T细胞中CD3基因的高表达可能与TCR介导信号的强大激活能力有关，表明这是脐带血T细胞低同种异体反应性的特征之一。
