Piechocki Marie P, Ho Ye-Shih, Pilon Shari, Wei Wei-Zen
Karmanos Cancer Institute, Department of Otolaryngology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
J Immunol. 2003 Dec 1;171(11):5787-94. doi: 10.4049/jimmunol.171.11.5787.
Her-2 transgenic (Tg) mice were generated with wild-type human c-ErbB-2 (Her-2) under the whey acidic protein promoter. They are tolerant to Her-2 and appropriate for testing Her-2 vaccines. The expression of transmembrane ErbB-2 from the whey acidic protein-Her-2 cassette and its up-regulation by insulin and hydrocortisone was verified by in vitro transfection. The transgene cassette was microinjected into fertilized eggs from B6C3 (C3H x C57BL/6) females mated with B6C3 males. Transgene-positive mice were backcrossed onto C57BL/6 mice. Human ErbB-2 was expressed in the secretory mammary epithelia during pregnancy and lactation and expressed constitutively in the Bergman glia cells within the molecular layer of the cerebellum. Overt, neoplastic transformation was not detected in any tissue examined. Tolerance to Her-2 was demonstrated by inoculating mice with a syngenic tumor expressing high levels of human ErbB-2. Tumors grew exclusively in Her-2 Tg mice without inducing an Ab response, while the nontransgenic littermates remained tumor free for 10 mo and mounted a robust anti-ErbB-2 Ab response. When immunized five times with plasmid DNA encoding secErbB-2 and GM-CSF, respectively, approximately 33% of the Her-2 Tg mice rejected a lethal challenge of EL-4/E2 tumor cells, whereas all immunized littermates rejected the tumor. Therefore, Her-2 Tg mice express human ErbB-2 in the brain and mammary gland and demonstrated tolerance to ErbB-2 which was partially overcome by DNA vaccination. The breakable tolerance of Her-2 Tg mice resembles that in human and these mice are particularly suited for testing human ErbB-2 based vaccines.
利用乳清酸性蛋白启动子调控野生型人c-ErbB-2（Her-2）构建了Her-2转基因（Tg）小鼠。它们对Her-2具有耐受性，适用于检测Her-2疫苗。通过体外转染验证了乳清酸性蛋白-Her-2盒中跨膜ErbB-2的表达及其受胰岛素和氢化可的松的上调。将转基因盒显微注射到与B6C3雄性交配的B6C3（C3H×C57BL/6）雌性的受精卵中。转基因阳性小鼠与C57BL/6小鼠回交。人ErbB-2在妊娠和哺乳期的分泌性乳腺上皮中表达，并在小脑分子层的伯格曼胶质细胞中组成性表达。在所检查的任何组织中均未检测到明显的肿瘤转化。通过给小鼠接种表达高水平人ErbB-2的同基因肿瘤证明了对Her-2的耐受性。肿瘤仅在Her-2 Tg小鼠中生长，未诱导抗体反应，而非转基因同窝小鼠在10个月内无肿瘤，并产生了强烈的抗ErbB-2抗体反应。当分别用编码secErbB-2和GM-CSF的质粒DNA免疫5次时，约33%的Her-2 Tg小鼠拒绝了EL-4/E2肿瘤细胞的致死性攻击，而所有免疫的同窝小鼠都拒绝了肿瘤。因此，Her-2 Tg小鼠在脑和乳腺中表达人ErbB-2，并表现出对ErbB-2的耐受性，DNA疫苗部分克服了这种耐受性。Her-2 Tg小鼠的可打破耐受性与人相似，这些小鼠特别适合于检测基于人ErbB-2的疫苗。
