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方法。然而，这些新药的安全性是一个主要问题。尤其令人担忧的是，许多基于基因的药物会激活先天免疫系统。这会导致释放高度炎症的细胞因子，如I型干扰素和IL-6，这对接受者可能是有毒的，甚至是致命的。这种先天反应还会引发适应性免疫反应，导致产生针对治疗性转基因产品的抗体，以及能够杀死表达替代基因的细胞的细胞毒性T细胞，从而消除治疗的好处。尽管对基于基因的药物进行化合物特异性修饰有时可以防止先天反应，但迫切需要一种更普遍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防止对基于基因的药物的炎症反应，并使用基因转移来诱导抗原特异性耐受，以防止不想要的免疫反应。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)针对这些途径来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轴是对核酸的先天性反应所需的一条基本途径(Agudo等人)。自然免疫学2014)。根据我们的发现，我们假设miR-126-VEGF信号通路控制着一组浆细胞样树突状细胞(PDC)的稳态和功能，PDC负责识别和启动对治疗性DNA和RNA的炎症反应，使用临床批准的药物阻断这一途径可以削弱对特定基因药物的先天和获得性免疫反应，包括慢病毒载体和短干扰RNA(SiRNA)。为了验证我们的假设，我们将：(1)确定小鼠和人类miR-126在对治疗性载体和寡核苷酸的固有反应中的功能；(2)确定调节小鼠和人VEGFR2信号对治疗性核酸引起的炎症反应的影响；以及(3)评估将抗原靶向我们已确定的非被核酸激活的新的PDC亚群，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天然免疫，特别是与核酸和DC之间的相互作用有关的新见解，为预防某些基因和基于寡核苷酸的治疗的炎症反应提供临床适用的手段，并建立诱导对某种抗原的耐受的策略，这将为血友病患者逆转自身免疫和防止替代凝血因子的免疫反应的疫苗奠定基础。

 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.