Development of Antibody and T-Cell Inducing Vaccines

通过诱导针对确定的碳水化合物和肽抗原的抗体的疫苗以及通过激活T淋巴细胞的疫苗，可以在实验动物中打破免疫耐受性并引起肿瘤排斥。这两种疫苗的靶抗原和最佳设计通常是完全不同的。然而，卵巢癌的免疫治疗理想地应该利用这两种类型的疫苗;我们最初将分别关注每种疫苗。该项目正从专门关注诱导抗体的疫苗过渡到更广泛的方法。在当前 在本申请中，我们用产生的抗体诱导多价疫苗进行最终的II期试验，并将我们的重点转移到T细胞诱导疫苗。诱导抗体的疫苗更先进，这主要是因为长期以来一直有血清学检测来监测疫苗的开发。因此，在目前的中期资助期间，我们将完成一系列单价结合疫苗的试点试验，为我们的多价KLH结合疫苗的II期试验做准备。这项试验是基于我们在碳水化合物合成、碳水化合物和肽与载体蛋白的化学结合以及免疫佐剂方面的独特专业知识和经验。在目的1方面，我们会就第四项计划下进行的第II期试验进行血清学分析。该试验的主要目的是确定诱导针对在卵巢癌细胞表面广泛表达的六至八种卵巢癌抗原（GM 2、globo H、Le-y、sTn、TF、MUC 1以及可能的MUC 16和KSA）的抗体的临床结果。本试验的次要目的是a）确认不同批次疫苗随时间的效力，并确定针对特定抗原的抗体应答与B）临床病程或c）卵巢癌复发中表达的抗原之间的相关性。这三个次要目标将在本项目中得到解决。 最近，已经开发了能够检测疫苗诱导的T细胞反应性而不需要延长体外致敏的测定法。这使我们能够遵循与开发抗体诱导疫苗相同的分步过程。我们将建立在我们独特的经验与这些检测，我们的经验与CA 125/MUC 16和Wilm的肿瘤抗原（WT 1）抗原，并与使用heteroclitic肽，电穿孔，和各种方法，旨在提高DNA疫苗的免疫原性。我们将通过一系列试点试验来启动这一过程，比较不同的方法来增强CA 125/MUC 16和WT 1的免疫原性。在这些试验中待检测方法的选择将部分基于正在进行的临床前研究和临床试验的结果。在目标2中，我们将重点关注异型肽、人MUC 16 B4组分蛋白和小鼠WT 1蛋白。在目标3中，我们将测试编码人、异种或异型蛋白、C3 d和DHBc融合蛋白的DNA疫苗，以及电穿孔或编码GM-CSF的DNA的施用。

Immune tolerance can be broken and tumor rejection elicited in experimental animals by vaccines that induce antibodies against defined carbohydrate and peptide antigens and by vaccines that activate T-lymphocytes. The target antigens and optimal design for these two types of vaccines are generally quite different. Immunotherapy of ovarian cancer should ideally utilize both types of vaccines, however; we will initially focus on each separately. This Project is in transition from an exclusive focus on vaccines that induce antibodies to a more broad approach. In the current application we perform a final Phase II trial with the resulting antibody-inducing polyvalent vaccine and shift our focus to T-cell-inducing vaccines. Vaccines that induce antibodies are more advanced, largely because of the long availability of serologic assays to monitor vaccine development. Consequently, during the current interim funding period we will conclude a series of pilot trials with monovalent conjugate vaccines in preparation for a Phase II trial with our polyvalent KLH-conjugate vaccine. This trial is based on our unique expertise and experience in carbohydrate synthesis, chemical conjugation of carbohydrates and peptides to carrier proteins, and immunological adjuvants. In Aim 1, we will perform the serological analysis on the Phase II trial conducted under the fourth Project. The primary objective of the trial is to determine the clinical consequences of inducing antibodies against six to eight ovarian cancer antigens (GM2, globo H, Le-y, sTn, TF, MUC1, and possibly MUC 16 and KSA) widely expressed on the ovarian cancer cell surface. The secondary objectives of the trial are to a) confirm the potency of different batches of vaccine prepared over time, and to determine the correlation between antibody response against particular antigens and b) clinical course or c) antigens expressed in ovarian cancer recurrences. These three secondary objectives will be addressed in this Project. Recently, assays capable of detecting vaccine-induced T-cell reactivity without the need for prolonged in vitro sensitization have been developed. This now permits us to follow the same step-by-step process used in developing antibody-inducing vaccines. We will build on our unique experience with these assays, our experience with the CA125/MUC16 and Wilm's Tumor Antigen (WT1) antigens, and with the use of heteroclitic peptides, electroporation, and a variety of approaches designed to augment the immunogenicity of DNA vaccines. We will initiate this process with a series of pilot trials comparing different approaches to augmenting the immunogenicity of CA125/MUC16 and WT1. Selection of the approaches to be tested in these trials will be based in part on results of ongoing preclinical studies and clinical trials. In Aim 2 we will focus on heteroclitic peptides, human MUC16 B4 fraction protein and murine WT1 protein. In Aim 3 we will test DNA vaccines coding for human, xenogeneic or heteroclitic proteins, C3d and DHBc fusion proteins, and administration with electroporation or DNA coding for GM-CSF.