Multiple Tumor Antigen-loaded DC Vaccine for Hepatocellular Cancer

描述（由申请人提供）：我们的中心假设是，用合理设计的基于树突状细胞（DC）的疫苗免疫肝细胞癌（HCC）患者，该疫苗呈递HCC相关肿瘤抗原AFP、磷脂酰肌醇蛋白聚糖-3和MAGE-A3，将导致识别肿瘤的CD8+和CD4 + T细胞活化。这种广泛的多克隆多抗原免疫也将激活NK细胞并改善疾病进展时间（TTP）和健康相关的生活质量（HRQL）。我们将测试差异负载3种确定抗原的DC疫苗以促进广泛免疫。DC将是蛋白质喂养的、腺病毒转导的和肽脉冲的。这将导致抗原存在于内体中（来自蛋白质喂养的抗原）、细胞质中（AdV递送的抗原）和表面上（肽脉冲的）。这种设置将允许直接比较来自单一疫苗的这三种抗原呈递模式，并且还允许比较疫苗递送的CD4 + T细胞辅助（AFP，GPC 3）与仅直接CD8+活化（MAGE-A3）对相应CD8 + T细胞的频率变化、功能质量和寿命的影响。A.1具体目标抗原加工和呈递。在这个目标中，我们将在临床前的体外环境中分析HBV +/HCV + HCC患者DC中负载抗原的细胞内加工。我们将解决几个机制的差异加载的DC疫苗的问题：蛋白质摄取的机制;细胞内抗原定位;抗原存在和呈递的持续时间; DC成熟的影响;和信号转导通路激活。A.2具体目标淋巴细胞活化。在这个目标中，我们将分析肝癌患者DC中全长抗原（AFP，GPC 3）和MHC I类限制性肽表位的呈递结果。我们将处理：CD8+和CD4 + T细胞活化，其表型和功能; NK细胞活化，以及调节性T细胞（Treg）活化或抑制的潜力。A.3具体目标I期初步临床试验。为此，我们将招募20名AFP + HCC患者并使用多抗原负载的DC疫苗进行接种。A.4具体目标疫苗应答的免疫学评估。在这一目标中，我们将表征对疫苗呈递抗原的免疫应答;确定NK应答;测试血清肿瘤标志物、生物标志物和Treg，并测试与免疫和临床应答的相关性。基于这一新信息的疫苗的合理设计应该允许通过更新的疫苗实现免疫激活的更合理的设计。 公共卫生相关性：在全球范围内，每年至少有600，000例肝细胞癌新发病例，美国有超过21，000例新发病例，美国每年有超过18，000例肝细胞癌（HCC）死亡。HCC的发病率在过去几十年中有所上升（由于美国HCV感染的增加）。5年生存率仅为2 - 8%。由于缺乏早期发现，大多数治疗只是治标不治本。因此，HCC的发病率持续上升，并将成为下半个世纪更大的健康问题。

DESCRIPTION (provided by applicant): Our Central Hypothesis is that immunization of hepatocellular cancer (HCC) patients with a rationally-designed dendritic cell (DC)-based vaccine which presents HCC- associated tumor antigens AFP, glypican-3 and MAGE-A3 will result in activation of CD8+ and CD4+ T cells which recognize tumors. This broad, polyclonal, multi-antigen immunity will also activate NK cells and improve time to progression (TTP) and health-related quality of life (HRQL). We will test a DC vaccine differentially loaded with 3 defined antigens to promote broad immunity. DC will be protein-fed, adenovirally-transduced and peptide-pulsed. This will result in antigen presence in endosomes (from protein-fed antigen), in the cytoplasm (AdV-delivered antigen) and on the surface (peptide-pulsed). This setting will allow direct comparison of these three modes of antigen presentation from a single vaccine, and also allow for a comparison of vaccine-delivered CD4+ T cell help (AFP, GPC3) with direct CD8+ activation only (MAGE-A3) on the frequency changes, functional quality and longevity of the corresponding CD8+ T cells. A.1 Specific Aim 1. Antigen Processing and Presentation. In this aim, we will analyze the intracellular processing of the loaded antigens in HBV+/HCV+ HCC patient DC in a preclinical, in vitro, setting. We will address several mechanistic questions about the differentially loaded DC vaccines: mechanism of protein uptake; intracellular antigen localization; duration of antigen presence and presentation; the effect of DC maturation; and the signal transduction pathways activated. A.2 Specific Aim 2. Lymphocyte activation. In this aim, we will analyze the result of presentation of the full length antigens (AFP, GPC3) and MHC class I-restricted peptide epitopes in HCC patient DC. We will address: CD8+ and CD4+ T cell activation, their phenotype and their function; NK cell activation, and potential for regulatory T cell (Treg) activation or inhibition. A.3 Specific Aim 3. Phase I Pilot Clinical Trial. In this aim, we will enroll and vaccinate 20 AFP+ HCC patients with the multi-antigen loaded DC vaccine. A.4 Specific Aim 4. Immunological Assessment of Vaccine Responses. In this aim, we will characterize immune responses to vaccine-presented antigens; determine NK responses; test for serum tumor markers, biomarkers and Treg and test for correlation with immune and clinical responses. Rational design of vaccines, based on this new information should allow for more rational design of the immune activation to be achieved by newer vaccines. PUBLIC HEALTH RELEVANCE: Globally, there are at least 600,000 new cases of hepatocellular cancer each year, over 21,000 new cases in the U.S. and over 18,000 deaths from hepatocellular cancer (HCC) in the U.S. annually. The incidence of HCC has risen in the last several decades, (due to increased HCV infection in the U.S.) and the 5-year survival rate is only 2-8%. Most therapies are only palliative due to lack of early detection. Therefore, the incidence of HCC continues to rise, and will become an even greater health problem for the next half century.