Development of a Non-Tolerogenic Anti-DEC-205 Vaccine Delivery Platform

这份U19三合会技术开发建议书描述了一项旨在开发 基于树突状细胞的高效、促炎和非耐受性疫苗递送系统 靶向抗DEC-205抗体。抗DEC-205作为强炎性免疫刺激物的成功 应答取决于非特异性树突状细胞成熟因子的联合应用。在他们不在的情况下，反 DEC-205诱导的是抗原特异性耐受，而不是免疫。因为与非特定项目相关的危险 激活免疫系统，我们建议开发一种改良的促炎和非耐受性 抗DEC-205抗体。我们发现了一组天然的调节性T细胞表位 通过刺激调节性T细胞诱导耐受的人免疫球蛋白。我们已经核实了 实验上，这些表位产生抗原特异性的调节性T细胞的扩增并抑制 炎性免疫反应。我们推测抗DEC-205中包含的调节性T细胞表位 促进只有通过联合使用非特异性免疫刺激剂才能克服的耐受性反应。 我们预计，这些表位的修饰将显著降低耐受性，从而能够使用 将抗DEC-205作为一种独立的、高性能的抗原传递系统。我们将通过以下方式消除对DEC-205的容忍 首先在(人源化的)小鼠模型系统中开始的两阶段过程中的表位修饰 正在进行人体血液样本的检测。使用Triad工具包核心免疫信息学算法，我们将重新设计 抗DEC-205，使其调节T细胞表位中的关键氨基酸被替换为 实验表明它们会干扰人类白细胞抗原的结合。然后我们将(1)产生一组抗体变体 重组结合到测试抗原，包括三合会研究项目中确定的候选疫苗， (2)识别不干扰树突状细胞靶向的去耐受突变，以及(3)评估变体 用于降低耐受性，以及提高疫苗抗原的免疫原性。

This U19 TRIAD Technology Development proposal describes an innovative program aimed at developing a high-performance, pro-inflammatory and non-tolerogenic vaccine delivery system based on the dendritic cell targeting anti-DEC-205 antibody. The success of anti-DEC-205 as a stimulator of strong inflammatory immune responses depends on co-administration of non-specific dendritic cell maturation factors. In their absence, anti- DEC-205 induces antigen-specific tolerance rather than immunity. Because of the dangers associated with nonspecific activation of the immune system, we propose to develop a modified pro-inflammatory and nontolerogenic anti-DEC-205 antibody. We have discovered a set of natural regulatory T-cell epitopes derived from human immunoglobulins that induce tolerance by stimulating regulatory T cells. We have verified experimentally that these epitopes generate antigen-specific expansion of regulatory T cells and suppress inflammatory immune responses. We hypothesize that regulatory T-cell epitopes contained in anti-DEC-205 promote a tolerogenic reaction that is only overcome through co-administration of non-specific immunostimulators. We expect that modification of these epitopes will significantly diminish tolerogenicity, enabling use of anti-DEC-205 as a stand-alone, high performance antigen delivery system. We will de-tolerize anti-DEC-205 by epitope modification in a two-stage process beginning first in a (humanized) mouse model system and progressing to human blood samples. Using TRIAD Toolkit Core immuno-informatics algorithms, we will reengineer anti-DEC-205 such that key amino acids in its regulatory T-cell epitopes are replaced with those that are experimentally shown to interfere with HLA binding. We will then (1) produce a set of antibody variants recombinantly conjugated to test antigens including vaccine candidates identified in TRIAD Research Projects, (2) identify de-tolerizing mutations that do not interfere with dendritic cell targeting, and (3) evaluate variants for reduced tolerogenicity, as well as for enhanced immunogenicity for vaccine antigens.