PRENATAL DIETHYLSTILBESTROL EXPOSURE--IMMUNE DEFECTS

对人类和动物的研究表明， 合成雌激素，己烯雌酚（DES），增加 肿瘤和致畸异常的易感性 生殖组织现在人们又提出了更多的关切， 产前暴露于DES的孕妇也易患自身免疫性疾病。 动物研究也证明，雌激素化合物具有显著的 对免疫系统的影响例如，正常小鼠围产期暴露于 雌激素会使胸腺萎缩并产生自身免疫。这些小鼠 增殖为T细胞有丝分裂原的能力受损，这是一种“生命”， 暗示免疫印记的“长”缺陷。T细胞缺陷 由DES诱导的可能有助于增加对肿瘤的易感性， 自身免疫性或感染性疾病、肿瘤或感染。我们假设 胎儿暴露于DES（在免疫系统的关键阶段 发育）可能会扭曲T细胞个体发育。这可能会导致个人 免疫系统受损的人为了验证这一假设，我们将重点 本研究对人外周血T细胞的表型和功能进行了研究， 注射DES的怀孕小鼠。将从胎仔至 衰老年龄，以确定免疫学变化是否是短暂的 或者永久的 本提案的目的是： 产前暴露于DES的小鼠胸腺内T细胞个体发育。DES- T细胞个体发育中的敏感阶段将通过使用单克隆抗体来确定。 通过流式细胞术检测发育调节表面标志物的抗体 细胞仪此外，将测定胸腺细胞的凋亡， 与凋亡标志基因fas的表达相关。目的二：为了 产前DES暴露者脾脏T细胞增殖的解剖缺陷 mice..将分析T细胞的以下变化： CD 3 +/α β TCR+细胞，活化标志物的表达，对 细胞因子（例如，IL-2，IL-12），细胞内Ca++水平和对 共刺激信号。目的三：分析研究的意义和性质 DES诱导的T细胞缺陷，通过确定是否：（i）增加的IgG 雌激素中抗dsDNA和心磷脂（一种磷脂）的自身抗体- 暴露的小鼠是脾或肝T细胞帮助改变的结果。 （ii）Th 1和Th 2亚群失衡。将会转向 Th 2可以解释自身抗体表达增加或T细胞减少。 细胞介导的免疫;（iii）体内T细胞应答的改变， Th 1诱导抗原（流产B.abortus）。预计这些研究 将提供新的信息，对胎儿的发展， 高雌激素的母体环境，即，潜在的成因 T细胞的先天缺陷。

Studies in humans and animals have shown that prenatal-exposure to a synthetic estrogen hormone, diethylstilbestrol (DES), increases susceptibility to neoplastic and teratogenic abnormalities of reproductive tissues. Additional concerns have now been raised that women prenatally-exposed to DES are also susceptible to autoimmune diseases. Animal studies also document that estrogenic compounds have a marked effect on the immune system. For example, normal mice perinatally exposed to estrogen have atrophied thymus and develop autoimmunity. These mice have impaired ability to proliferate to T cell mitogens, which is a "life long" defect suggestive of immunologic imprinting. Defects of T cells induced by DES may contribute to increased susceptibility to neoplastic, autoimmune or infectious diseases, tumors or infection. We hypothesize that exposure of fetuses to DES (at a critical stage of immune system development) may skew the T cell ontogeny. This may result in individuals with an impaired immune system. To test this hypothesis, we will focus our studies on the phenotype and function of T cells from offspring of pregnant mice injected with DES. Mice will be examined from fetal to senescent age to determine whether immunological changes are transient or permanent. The aims of this proposal are; Aim I: To delineate the intrathymic T cell ontogeny in mice prenatally-exposed to DES. The DES- sensitive stage in T-cell ontogeny will be determined by using monoclonal antibodies to developmentally-regulated surface markers by flow cytometry. Further, apoptosis of thymocytes will be determined and correlated with expression of fas, an apoptotic marker gene. Aim Il: To dissect defects in splenic T cell proliferation in prenatal DES-exposed mice.. T cells will be analyzed for alterations in: numbers of splenic CD3+/alphaBeta TCR+ cells, expression of activation markers, response to cytokines (eg. IL-2, IL-12), intracellular Ca++ levels and response to co-stimulatory signals. Aim III: To analyze the significance and nature of DES-induced T cell defects by determining whether: (i) augmented IgG autoantibodies to dsDNA and cardiolipin (a phospholipid) in estrogen- exposed mice is a consequence of altered help from spleen or liver T cells; (ii) there is an imbalance of Th1 and Th2 subsets. A shift towards Th2, may explain increased expression of autoantibodies or diminished T- cell mediated immunity; (iii) alterations in T cell response in vivo to Th1-inducer antigens (B.abortus). It is anticipated that these studies will provide new information on the hazards of development of fetuses in a hyperestrogenic maternal environment, i.e., potential for the genesis of birth defects of T cells.