Hunt D W, Huppertz H I, Jiang H J, Petty R E
Department of Paediatrics, University of British Columbia, Vancouver, Canada.
Blood. 1994 Dec 15;84(12):4333-43.
We have isolated low-density, nonadherent, nonphagocytic, HLA-DR+ve cells with the morphology of dendritic cells (DCs) from the cord blood of full-term newborn infants. Relative to adult DCs, cord blood DCs were poor stimulators of the mixed leukocyte reaction when either adult or cord blood mononuclear cells (MNCs) or T lymphocytes were used as responder cells. In contrast, cord blood T cells and MNCs responded normally to allogeneic adult DCs. Cord blood DCs performed poorly as accessory cells for T-lymphocyte mitogenic responses at suboptimal concentrations of concanavalin A (Con A) and phytohemagglutinin A or at optimal concentrations of mitogen and low numbers of DCs. Addition of recombinant interleukin-2 (rIL-2) or recombinant interferon-gamma (rIFN-gamma) to cord blood DC-T-cell cultures containing a suboptimal concentration of Con A potentiated the proliferative response. In contrast, rIL-2 and rIFN-gamma exerted little effect on the proliferative response of adult T cells cultured with Con A and DCs. Flow cytometric studies showed that levels of intercellular adhesion molecule-1 (ICAM-1; CD54) and major histocompatibility complex (MHC) class I HLA-ABC and class II HLA-DR antigens on cord blood DCs were significantly lower than those on adult blood DCs. These findings suggest that the relative inefficiency of cord blood DCs in the activation of T cells may be related to their low cell surface expression of MHC and cell adhesion molecules. The demonstrated impairment of cord blood DC function could be of importance in understanding the immunologic relationship between the fetus and mother and could contribute to the susceptibility of newborns to infection.
我们从足月新生儿的脐带血中分离出了低密度、不黏附、非吞噬性、HLA - DR阳性且具有树突状细胞（DCs）形态的细胞。相对于成人DCs，当使用成人或脐带血单个核细胞（MNCs）或T淋巴细胞作为反应细胞时，脐带血DCs对混合淋巴细胞反应的刺激能力较差。相比之下，脐带血T细胞和MNCs对同种异体成人DCs反应正常。在次优浓度的刀豆蛋白A（Con A）和植物血凝素A条件下，或在最佳浓度的丝裂原和少量DCs条件下，脐带血DCs作为T淋巴细胞有丝分裂反应的辅助细胞表现不佳。向含有次优浓度Con A的脐带血DC - T细胞培养物中添加重组白细胞介素 - 2（rIL - 2）或重组干扰素 - γ（rIFN - γ）可增强增殖反应。相比之下，rIL - 2和rIFN - γ对与Con A和DCs一起培养的成人T细胞的增殖反应影响很小。流式细胞术研究表明，脐带血DCs上细胞间黏附分子 - 1（ICAM - 1；CD54）以及主要组织相容性复合体（MHC）I类HLA - ABC和II类HLA - DR抗原的水平显著低于成人血液DCs。这些发现表明，脐带血DCs在激活T细胞方面相对低效可能与其细胞表面MHC和细胞黏附分子的低表达有关。所证明的脐带血DC功能受损可能对理解胎儿与母亲之间的免疫关系具有重要意义，并且可能导致新生儿易受感染。
