HER 2/Neu--A Target For Cancer Immunotherapy

描述（由申请人提供）：本提案的总体目标是 应用基于抗独特型（Id）的疫苗方法治疗 HER 2/neu阳性人类癌症。HER 2/neu扩增和/或过表达 在多种人类恶性肿瘤中发生，并且与不良预后相关。 人源化抗HER 2/neu mAb，4D 5（赫赛汀）在给药时具有治疗作用 对于转移性乳腺癌患者的子集，尤其是在 联合化疗。这些令人兴奋的结果提供了一个基础， 进一步开发新的基于抗体的癌症治疗策略。 一种这样的策略是主动特异性免疫疗法，其中宿主免疫应答被激活。 系统靶向表达HER 2/neu的肿瘤细胞。我们建议发展 “内部图像”抗Id疫苗，将类似于三维 HER2/neu。用这种抗Id疫苗进行免疫接种， 耐受性和诱导持续高滴度HER 2/neu特异性抗体， 患者在基因不受限制的方式。我们将针对临床上 已证实的HER 2/neu保护性表位，由赫赛汀和mAb定义 520 C9识别不同的表位。Mouse mAb 4D5（parental antibody 对于赫赛汀）和520 C9将分别用作免疫抗体，或 Abi，将产生抗Ids或Ab 2。Ab 2将用于诱导 小鼠和兔中的抗HER 2/neu抗体（Abi '）。的交叉反应性 具有天然HER-2受体的诱导的抗抗Id（Ab 3）抗体将 通过流式细胞术、免疫组织化学和免疫沉淀测定 以相应阿比特龙为阳性对照。抗肿瘤活性 将在体外和体内评估Ab 3（Abi '）的活性。康贝特人将以 Ab 3介导的对HER 2/neu阳性癌细胞的生长抑制作用， 组织培养和异种移植的裸鼠中。的细胞和分子 将研究抗体诱导的生长抑制的机制。的 然后将测试潜在抗Id疫苗的治疗功效， 肿瘤保护以及在免疫活性细胞中建立的肿瘤的治疗 用HER 2/neu基因转导的癌细胞的鼠模型。 还将评估所选抗Id疫苗的免疫潜力。 在HER 2/neu转基因小鼠中评价。选择最佳方案的标准 抗Id疫苗将基于激发抗肿瘤活性的能力 在体外和体内。这项研究将是临床试验的前奏， HER 2/neu阳性癌症患者接种单一或联合抗Id疫苗。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to apply an anti-idiotype (Id) based vaccine approach for the treatment of HER2/neu positive human cancer. Amplification and/or overexpression of HER2/neu occurs in multiple human malignancies and is associated with a poor prognosis. A humanized anti-HER2/neu mAb, 4D5 (Herceptin) is therapeutic when administered for a subset of patients with metastatic breast cancer, especially in combination with chemotherapy. These exciting results provide a basis for further development of new antibody-based cancer therapy strategies. One such strategy is active specific immunotherapy in which the host immune system is targeted to HER2/neu expressing tumor cells. We propose to develop "internal image" anti-Id vaccines that will resemble the three- dimensional shapes of HER2/neu. Immunization with such an anti-Id vaccine will break immune tolerance and induce sustained high titer HER2/neu specific antibodies in patients in a genetically unrestricted fashion. We will target the clinically proven, protective epitopes of HER2/neu as defined by Herceptin and also by mAb 520C9 which recognizes a different epitope. Murine mAb 4D5 (parental antibody for Herceptin) and 520C9 will be used separately as the immunizing antibody or Abi to which anti-Ids or Ab2 will be generated. Ab2 will be used to induce anti-HER2/neu antibodies (Abi') in mice and rabbits. The cross-reactivities of the induced anti-anti-Id (Ab3) antibodies with the native HER-2 receptor will be determined by flow cytometry, immunohistochemistry, and immunoprecipitation with the use of corresponding Abi as positive control. The anti-tumor activity of Ab3 (Abi') will be assessed both in vitro and invivo. We will determine the Ab3 mediated growth inhibitory effects on HER2/neu positive cancer cells in tissue culture and in xenografted nude mice. The cellular and molecular mechanisms of antibody-induced growth inhibition will be investigated. The therapeutic efficacy of the potential anti-Id vaccines will then be tested for tumor protection as well as therapy of established tumors in an immunocompetent murine model of carcinoma cells transduced with the HER2/neu gene. Immunotherapeutic potential of the selected anti-Id vaccines will also be evaluated in HER2/neu transgenic mice. The criteria for selection of optimal anti-Id vaccines will be based on the ability to invoke anti-tumor activities in vitro and invivo. This study will be a prelude to clinical trials for HER2/neu positive cancer patients with a single or combined anti-Id vaccine.