DNA- and protein vaccination in combination with immune checkpoint blockade for active immunotherapy against neuroblsatoma

DNA 和蛋白质疫苗接种结合免疫检查点阻断用于针对神经母细胞瘤的主动免疫治疗

• 批准号: 275243372
• 负责人: Dr. Nikolai Siebert
• 金额: --
• 依托单位: Abteilung Pädiatrische Onkologie und Hämatologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/275243372?language=en
• 关键词: DNA; protein; vaccination; combination; immune

This renewal proposal describes two therapeutic strategies (DNA- and protein vaccination) for active immunotherapy against neuroblastoma (NB), the most common solid tumor in childhood. Since metastases are found in a majority of cases at diagnosis, the development of new therapeutic approaches against this aggressive malignancy is of great importance.The first therapeutic strategy we aim to use is based on vaccination with a bicistronic DNA plasmid encoding for both a tumor-associated antigen (TAA) and an immune stimulating cytokine. An ubiquitin sequence linked to the TAA ensures its proteasomal degradation and enhances presentation to cytotoxic T lymphocytes (CTLs), thus increasing a cellular anti-NB immune response. The secretion of a bioactive cytokine in microenvironment of the antigen presentation stimulates CTLs without induction of well-known cytokine-dependent side effects when administered systemically. The second therapeutic strategy implements a poor investigated concept of CTL activation by IgG-based protein vaccines based on the principle of cross-presentation. For this, we aim to investigate anti-tumor effects of vaccination with a fusion protein consisting of TAA epitopes linked to the constant heavy chain of human immunoglobulin G1. Here, the IgG structure facilitates the uptake of the fusion protein by antigen presenting cells resulting in increased presentation of TAA epitopes.The first bicistronic DNA vaccine is already generated and characterized. This vaccine encodes for the TAA tyrosine hydroxylase (TH), which is over expressed in NB, and the CTL stimulating cytokine interleukin 15 (IL-15). This project was funded by the DFG (project start: 01.07.2015; funding: 2 years; presumable overall duration: 4 years). Currently, we evaluate this vaccine in a pre-clinical model in combination with an immune checkpoint blockade (PD-1, CTLA-4 and regulatory T cells (Treg)).By analogy with the TH+IL-15-based vaccination strategy, a second bicistronic DNA vaccine against MYCN-positive tumors, that do not respond to standard therapy and are associated with poor survival, will be generated. To increase the efficacy of vaccination, an additional DNA sequence encoding for the cytokine IL-21, which stimulates CTL and inhibits Treg, will be integrated into the vaccine. Moreover, the new concept of an IgG-based MYCN fusion protein consisting of MYCN epitopes and IgG1 heavy chain will be investigated. Finally, the MYCN-based vaccines will be evaluated in combination with immuncheckpoint blockade (PD-1, CTLA-4, Treg).These multimodal strategies are important in that they combine TAA-specific anti-tumor response with immune stimulating agents (cytokines and/or inhibition of immune checkpoints), thus offering the potential for additive or synergistic anti-tumor efficacy.

该更新提案描述了两种治疗策略（DNA和蛋白质疫苗接种），用于针对神经母细胞瘤（NB）的主动免疫治疗，神经母细胞瘤是儿童最常见的实体瘤。由于在大多数情况下，在诊断中发现转移，新的治疗方法对这种侵略性的恶性肿瘤的发展是非常重要的，我们的目标是使用的第一个治疗策略是基于与编码肿瘤相关抗原（TAA）和免疫刺激细胞因子的双顺反子DNA质粒接种。与TAA连接的泛素序列确保其蛋白酶体降解并增强对细胞毒性T淋巴细胞（CTL）的呈递，从而增加细胞抗NB免疫应答。当全身施用时，在抗原呈递的微环境中生物活性细胞因子的分泌刺激CTL而不诱导众所周知的烟碱依赖性副作用。第二种治疗策略实施了基于交叉呈递原理的基于IgG的蛋白质疫苗的CTL活化的不良研究概念。为此，我们的目的是研究与TAA表位连接到人免疫球蛋白G1的恒定重链的融合蛋白疫苗接种的抗肿瘤效果。在这里，IgG结构促进抗原呈递细胞对融合蛋白的摄取，导致TAA表位的呈递增加。该疫苗编码在NB中过表达的TAA酪氨酸羟化酶（TH）和CTL刺激细胞因子白细胞介素15（IL-15）。该项目由DFG资助（项目开始日期：2015年7月1日;资助时间：2年;预计总持续时间：4年）。目前，我们在临床前模型中评估了这种疫苗与免疫检查点阻断（PD-1，CTLA-4和调节性T细胞（Treg））的组合。通过与基于TH+IL-15的疫苗接种策略类比，将产生针对MYCN阳性肿瘤的第二种双顺反子DNA疫苗，所述MYCN阳性肿瘤对标准疗法没有反应并且与较差的存活率相关。为了增加疫苗接种的功效，将编码刺激CTL并抑制Treg的细胞因子IL-21的额外DNA序列整合到疫苗中。此外，将研究由MYCN表位和IgG 1重链组成的基于IgG的MYCN融合蛋白的新概念。最后，将评估基于MYCN的疫苗与免疫检查点阻断（PD-1、CTLA-4、Treg）的组合。这些多模式策略的重要性在于，它们将联合收割机TAA特异性抗肿瘤应答与免疫刺激剂（细胞因子和/或免疫检查点抑制）相结合，从而提供了累加或协同抗肿瘤功效的潜力。