Modulating Immunity to Nucleic Acids and Inducing Tolerance by Gene Transfer

 描述：基因和寡核苷酸疗法有可能彻底改变许多疾病的治疗。然而，这些新药的安全性是一个主要问题。特别值得关注的是，许多基于基因的药物会触发先天免疫系统的激活。这会导致高度炎症细胞因子的释放，例如 I 型干扰素和 IL-6，这些细胞因子可能对受体有毒，甚至致命。先天反应还会启动适应性免疫反应，从而产生针对治疗性转基因产物的抗体，以及可以杀死表达替代基因的细胞的细胞毒性T细胞，并消除治疗的益处。尽管对基于基因的药物进行化合物特异性修饰有时可以阻止先天反应，但仍然非常需要一种更通用的方法来提高基因和寡核苷酸治疗的安全性和有效性。 我们的长期目标是开发一种方法来预防基因药物引起的炎症反应，并利用基因转移诱导抗原特异性耐受，以防止不必要的免疫反应。该项目的目标是：（i）确定控制对寡核苷酸和基因载体的先天反应的分子和细胞途径，（ii）瞄准这些途径以抑制对基因传递的先天反应，以及（ii）利用这种效应来诱导免疫耐受。 在最近的研究中，我们发现 miR-126-VEGFR2 轴是对核酸先天反应所需的重要途径（Agudo 等人，《自然免疫学》2014）。根据我们的研究结果，我们假设 miR-126-VEGF 信号通路控制浆细胞样树突状细胞 (pDC) 子集的稳态和功能，这些细胞负责识别和启动对治疗性 DNA 和 RNA 的炎症反应，并且使用临床批准的药物阻断该通路，可以减弱对特定基因药物（包括慢病毒载体和短干扰 RNA (siRNA)）的先天性和适应性免疫反应。 为了检验我们的假设，我们将：（1）确定小鼠和人类 miR-126 在对治疗载体和寡核苷酸的先天反应中的功能，（2）确定调节小鼠和人类 VEGFR2 信号传导对治疗性核酸炎症反应的影响，以及（3）评估将抗原靶向我们已识别的不被核酸激活的新 pDC 子集是否可以促进抗原特异性免疫耐受。我们的研究结果将：揭示对先天免疫的新见解，特别是与核酸和树突状细胞之间的相互作用有关的新见解，提供临床上适用的方法来预防对某些基因和寡核苷酸疗法的炎症反应，并建立诱导对抗原耐受的策略，这将成为逆转自身免疫和预防血友病患者对替代凝血因子的免疫反应的疫苗的基础。

 DESCRIPTION: Gene and oligonucleotide therapies have the potential to revolutionize the treatment of many diseases. However, the safety of these new drugs is a major issue. Of particular concern, many gene-based medicines trigger activation of the innate immune system. This results in the release of highly inflammatory cytokines, such as type I interferons and IL-6, which can be toxic to the recipient, and even deadly. The innate response also initiates an adaptive immune response that results in production of antibodies against the therapeutic transgene product, as well as cytotoxic T cells that can kill cells expressing the replacement gene, and eliminate the benefits of the therapy. Even though compound-specific modifications to gene-based drugs can sometimes prevent the innate response, a more general approach is greatly needed to improve the safety and efficacy of gene and oligonucleotide therapy. Our long-term goal is to develop a means to prevent the inflammatory response to gene-based drugs, and to use gene transfer to induce antigen-specific tolerance for preventing unwanted immune responses. The objectives of this project are: (i) to identify molecular and cellular pathways that control the innate response to oligonucleotides and gene vectors, (ii) to target these pathways to dampen the innate response to gene delivery, and (ii) to exploit this effect for inducing immunological tolerance. In recent studies, we have discovered that the miR-126-VEGFR2 axis serves as an essential pathway required for the innate response to nucleic acids (Agudo et al. Nature Immunology 2014). Based on our findings, we hypothesize that the miR-126-VEGF signaling pathway controls the homeostasis and function of a subset of plasmacytoid dendritic cells (pDC) that are responsible for recognizing and initiating the inflammatory response to therapeutic DNA and RNA, and that blocking this pathway, using clinically approved drugs, can blunt both the innate and adaptive immune response to specific gene-based drugs, including lentiviral vectors and short interfering RNAs (siRNA). To test our hypotheses, we will: (1) Identify the function of mouse and human miR-126 in the innate response to therapeutic vectors and oligonucleotides, (2) determine the impact of modulating mouse and human VEGFR2 signaling on the inflammatory response to therapeutic nucleic acids, and (3) evaluate whether targeting antigen to a new pDC subset that we have identified which are not activated by nucleic acids, can promote antigen-specific immune tolerance. The results of our studies will: uncover new insights into innate immunity, particularly related to the interactions between nucleic acids and DCs, provide a clinically applicable means to prevent the inflammatory response to some gene and oligo-based therapies, and establish a strategy for inducing tolerance to an antigen, which will form the basis of a vaccine for reversing autoimmunity and for preventing the immune response to replacement coagulation factor in hemophiliacs.