Leung K N, Yeung H W, Leung S O
Asian Pac J Allergy Immunol. 1986 Dec;4(2):111-20.
Trichosanthin, a basic protein purified from the root tuber of Trichosanthes kirilowii, has been used effectively in China to induce midterm abortion in humans. In this paper, we show that trichosanthin at non-cytotoxic concentrations markedly inhibited the mitogen-induced lymphoproliferative response and the generation of a primary alloreactive CTL response in vitro. Similarly, the production of IL-2 by Con A activated splenocytes and the in vitro effector functions of macrophages were also significantly suppressed. In contrast, the cytolytic activity of CTL and NK cells was unimpaired. Moreover, the in vivo activation of NK cells was not significantly altered by a single injection of a non-toxic microgram amount of trichosanthin into mice. However, other immune reactivities such as the induction of a DTH response and the humoral antibody formation to SRBC were markedly depressed. Our data suggest that trichosanthin is a potent immunosuppressive protein that could affect humoral immunity and a variety of cell-mediated processes. In addition, our preliminary results show that this abortifacient protein could also inhibit the growth of a murine malignant tumour (MBL-2), both in vivo and in vitro.
天花粉蛋白是从栝楼块根中纯化得到的一种碱性蛋白，在中国已被有效地用于诱导人类中期流产。在本文中，我们表明在非细胞毒性浓度下，天花粉蛋白显著抑制有丝分裂原诱导的淋巴细胞增殖反应以及体外初次同种异体反应性细胞毒性T淋巴细胞（CTL）反应的产生。同样，刀豆蛋白A激活的脾细胞产生白细胞介素-2以及巨噬细胞的体外效应功能也受到显著抑制。相比之下，CTL和自然杀伤（NK）细胞的细胞溶解活性未受损害。此外，向小鼠单次注射无毒微克量的天花粉蛋白对NK细胞的体内激活没有显著改变。然而，其他免疫反应性，如迟发型超敏反应（DTH）的诱导以及针对绵羊红细胞（SRBC）的体液抗体形成则明显受到抑制。我们的数据表明，天花粉蛋白是一种有效的免疫抑制蛋白，可影响体液免疫和多种细胞介导的过程。此外，我们的初步结果表明，这种堕胎蛋白在体内和体外也能抑制小鼠恶性肿瘤（MBL-2）的生长。
