Preijers F W, De Witte T, Rijke-Schilder G P, Tax W J, Wessels J M, Haanen C, Capel P J
Department of Hematology, University of Nijmegen, The Netherlands.
Scand J Immunol. 1988 Aug;28(2):185-94. doi: 10.1111/j.1365-3083.1988.tb02430.x.
Graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) is initiated by immunocompetent T cells present in the graft. Selective elimination of distinct T-cell subsets or a sufficient, but not complete T-cell depletion, might abolish severe GVHD without graft rejection and loss of the anti-tumour potential. In this study we analysed the efficacy of different monoclonal antibodies (MoAb) WT32 (CD3), OKT4 (CD4), T101 (CD5), WT1 (CD7), and WT82 (CD8) with respect to their cytotoxicity to T cells either as immunotoxin (IT) or in combination with complement. The cytotoxic potential was assessed by protein synthesis inhibition and clonogenic assays. The ricin A conjugated MoAb exerted only a minor effect on blood or bone marrow T cells, although they were highly inhibitory to T-cell lines. However, in the presence of 20 mM ammonium chloride, IT directed against CD3, CD5, and CD7 were highly cytotoxic. IT directed against CD4 and CD8 were less effective, due to a low internalization. The complement-mediated cytotoxicity was efficient for all antigens used. The natural killer (NK) activity, as measured by cytotoxicity to K562, was hardly depressed by anti-CD3, anti-CD4, anti-CD5, and anti-CD8, but was eliminated by anti-CD7. All procedures used had only a minimal effect on haematopoietic progenitors as measured by CFU-GM and BFU-E assays. We concluded that, although the T-cell population can be eliminated with the combination of anti-CD3, anti-CD5, and anti-CD7 antibodies plus complement, IT with 20 mM NH4Cl appear to kill higher amounts of T cells. Selective elimination of CD4- and CD8-positive cells is effectively obtained by MoAb with complement.
异基因骨髓移植（BMT）后的移植物抗宿主病（GVHD）由移植物中存在的免疫活性T细胞引发。选择性清除不同的T细胞亚群或进行充分但不完全的T细胞清除，可能会消除严重的GVHD，同时避免移植物排斥和抗肿瘤潜力的丧失。在本研究中，我们分析了不同单克隆抗体（MoAb）WT32（CD3）、OKT4（CD4）、T101（CD5）、WT1（CD7）和WT82（CD8）作为免疫毒素（IT）或与补体联合使用时对T细胞的细胞毒性。通过蛋白质合成抑制和克隆形成试验评估细胞毒性潜力。蓖麻毒素A偶联的MoAb对血液或骨髓T细胞仅产生轻微影响，尽管它们对T细胞系具有高度抑制作用。然而，在存在20 mM氯化铵的情况下，针对CD3、CD5和CD7的IT具有高度细胞毒性。针对CD4和CD8的IT效果较差，因为内化率较低。补体介导的细胞毒性对所有使用的抗原均有效。通过对K562的细胞毒性测量的自然杀伤（NK）活性，几乎不受抗CD3、抗CD4、抗CD5和抗CD8的抑制，但被抗CD7消除。通过CFU-GM和BFU-E试验测量，所有使用的程序对造血祖细胞的影响都很小。我们得出结论，尽管联合使用抗CD3、抗CD5和抗CD7抗体加补体可以消除T细胞群体，但含20 mM NH4Cl的IT似乎能杀死更多的T细胞。通过MoAb与补体可有效选择性清除CD4和CD8阳性细胞。
