Multiple Tumor Antigen-loaded DC Vaccine for Hepatocellular Cancer

描述(申请人提供)：我们的中心假设是，用一种合理设计的树突状细胞(DC)疫苗免疫肝癌患者，该疫苗提供与肝癌相关的肿瘤抗原AFP、GLYPICAN-3和MAGE-A3，将导致识别肿瘤的CD8+和CD4+T细胞的激活。这种广泛的多克隆多抗原免疫还将激活NK细胞，改善进展时间(TTP)和与健康相关的生活质量(HRQL)。我们将测试一种不同负载3种已定义抗原的DC疫苗，以促进广泛免疫。树突状细胞将被蛋白质喂养、腺病毒转导和多肽冲击。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(多肽冲击的)。这一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，还允许比较疫苗传递的CD4+T细胞帮助(AFP，GPC3)和仅CD8+直接激活(MAGE-A3)在相应CD8+T细胞的频率变化、功能质量和寿命方面的比较。A.1特定目标1.抗原处理和呈递。在这一目标中，我们将分析在临床前的体外环境下，乙肝病毒+/丙型肝炎病毒+肝癌患者DC负载抗原的细胞内处理过程。我们将解决有关不同负载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；DC成熟的影响；以及激活的信号转导通路。A.2特定目标2.激活淋巴细胞。为此，我们将分析全长抗原(AFP、GPC3)和MHC-I类限制性多肽表位在肝癌患者DC中的呈递结果。我们将讨论：CD8+和CD4+T细胞的激活，它们的表型和功能；NK细胞的激活，以及调节性T细胞(Treg)激活或抑制的可能性。A.3具体目标3.第一阶段试点临床试验。为此，我们将招募20名AFP+肝癌患者接种多抗原负载的DC疫苗。A.4具体目标4.疫苗反应的免疫学评估在这一目标中，我们将表征对疫苗呈现的抗原的免疫反应；确定NK反应；检测血清肿瘤标志物、生物标志物和Treg，并测试与免疫和临床反应的相关性。基于这些新信息的疫苗的合理设计应该允许更合理的设计较新的疫苗实现免疫激活。 公共卫生相关性：全球每年至少有60万例新发肝细胞癌病例，美国每年有超过2.1万例新病例，美国每年有超过1.8万人死于肝细胞癌。在过去的几十年里，肝癌的发病率有所上升(原因是美国的丙型肝炎病毒感染增加)。而5年存活率只有2-8%。由于缺乏早期发现，大多数治疗都只是姑息治疗。因此，肝癌的发病率继续上升，并将成为未来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.