Zhu H, Sun Z, Dai H
Central Lab of Hematological Department, Anhui Provincial Hospital, Hefei 230001, China.
Zhonghua Xue Ye Xue Za Zhi. 2001 Aug;22(8):423-5.
To explore immunologic function of T lymphocytes in human cord blood (HUCB) and provide theoretical basis for clinical application of HUCB.
Immunophenotype and co-stimulated molecules were detected by flow-cytometry using a panel of double labelled McAb, intracellular cytokines (interferon-gamma, interleukin-4) secreted by T lymphocytes by micro-culture of whole blood, and CD25 expression of T lymphocyte by PHA stimulation. T lymphocytes from adult peripheral blood (PB) were used as control.
There are a higher CD4+/CD8+ ratio of T subset and a lower percentage of CD8+ lymphocytes in HUCB than that in adult PB (P < 0.01), and more than 90% of HUCB T-cells co-expressed CD45RA naive antigen which was significant higher than the percentage in adult PB (P < 0.01). The percentages of IFN-gamma and IL-4-producing CD4+ and CD8+ T cells from HUCB were lower than that of the control group. T cells in HUCB were able to be activated by PHA, but the phases of activation differed from adult PB T cells.
It suggested that the low ability to secret cytokines and high percentage of naive T cells might be responsible for the decreased incidence of acute and chronic GVHD and provided possible explanation for the clinical result in HUCB transplantation. T cells in HUCB is a potential resource of adoptive immunotherapy.
探讨人脐血（HUCB）中T淋巴细胞的免疫功能，为HUCB的临床应用提供理论依据。
采用一组双标记单克隆抗体通过流式细胞术检测免疫表型和共刺激分子，通过全血微量培养检测T淋巴细胞分泌的细胞内细胞因子（干扰素-γ、白细胞介素-4），以及通过PHA刺激检测T淋巴细胞的CD25表达。以成人外周血（PB）中的T淋巴细胞作为对照。
与成人PB相比，HUCB中T亚群的CD4+/CD8+比值较高，CD8+淋巴细胞百分比较低（P<0.01），且超过90%的HUCB T细胞共表达CD45RA幼稚抗原，这一比例显著高于成人PB中的百分比（P<0.01）。HUCB中产生IFN-γ和IL-4的CD4+和CD8+ T细胞百分比低于对照组。HUCB中的T细胞能够被PHA激活，但激活阶段与成人PB T细胞不同。
提示细胞因子分泌能力低和幼稚T细胞百分比高可能是急性和慢性移植物抗宿主病发生率降低的原因，并为HUCB移植的临床结果提供了可能的解释。HUCB中的T细胞是过继性免疫治疗的潜在资源。
