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，合理设计的树突状细胞（DC）疫苗免疫肝癌（HCC）患者，该疫苗含有HCC相关的肿瘤抗原AFP、glypican-3和MAGE-A3，可激活识别肿瘤的CD8+和CD4+ T细胞。这种广泛的、多克隆、多抗原免疫也会激活NK细胞，改善进展时间（TTP）和健康相关生活质量（HRQL）。我们将测试一种DC疫苗，不同地装载3种确定的抗原，以促进广泛免疫。DC将是蛋白质喂养，腺病毒转导和肽脉冲。这将导致抗原存在于内体（来自蛋白质喂养的抗原）、细胞质（adv递送的抗原）和表面（肽脉冲）。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细胞帮助（AFP, GPC3）与仅直接激活CD8+ (MAGE-A3)的频率变化，相应CD8+ T细胞的功能质量和寿命。A.1具体目标抗原加工与递呈。在这个目的中，我们将在临床前体外环境中分析HBV+/HCV+ HCC患者DC中负载抗原的细胞内加工。我们将解决关于差异负载DC疫苗的几个机制问题：蛋白质摄取机制；细胞内抗原定位；抗原存在和呈递的持续时间；直流成熟的影响；信号转导通路被激活。A.2具体目标淋巴细胞激活。在这个目的中，我们将分析HCC患者DC中全长抗原（AFP, GPC3）和MHC i类限制性肽表位的呈递结果。我们将讨论：CD8+和CD4+ T细胞活化，它们的表型和功能；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期试点临床试验。为此，我们将招募20例AFP+ HCC患者接种多抗原负载DC疫苗。A.4具体目标疫苗反应的免疫学评价。为此，我们将描述对疫苗呈递抗原的免疫反应；测定NK反应；血清肿瘤标志物、生物标志物和Treg的检测以及与免疫和临床反应的相关性检测。基于这一新信息的合理疫苗设计应该允许更合理的免疫激活设计，以实现新疫苗。

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.