Synthetic mRNA-mediated reversible immunocontraception

项目摘要 目前，72%的避孕妇女使用激素避孕法，但经常出现不满情绪。 由于生活质量和安全方面的考虑，因此，显然需要新的 非激素女性避孕药的方法，易于使用，妇女应用，并有一个 可控制的作用持续时间。可逆免疫避孕提供了一种非激素的解决方案，其中抗- 精子抗体被引入雌性生殖道（FRT）并抑制精子功能。这 然而，这种方法有许多挑战，包括：发现一种特异有效的单克隆抗体， 抗人精子抗原的单克隆抗体（mAb），以及引入mAb的安全可靠的方法， 时间和空间可控。对于这项拨款申请，生殖生物学专业知识和分子 工具箱已被汇集在一起，以克服这些挑战。一种抗精子抗体已经被发现 具有影响生育力的明确的作用机制，并确定了一种创新方法， 将抗体输送到FRT。在这里，提出了一种基于合成mRNA的方法， FRT的凝集和粘液捕获抗体。到目前为止，表达高水平抗体的能力， 已经证明了在绵羊的FRT中单次施用mRNA超过28天。递送是 通过将FRT上皮直接、快速、气溶胶暴露于水中的裸mRNA来实现。持久性 通过将GPI-接头掺入抗体的重链中， 抗体的这种组合允许快速递送和表达，以及可控制的持续性， 分泌物中的保护性mAb。在R61阶段，相关条件下的输送机制将是 优化和探索;抗体设计问题也将得到解决，这将允许可调的持久性 粘液分泌物中的抗体。在R33阶段，药代动力学实验将在 猕猴，以及持续的抗体优化。最后，精子挑战实验将在 体内试验以证明疗效。长期目标是开发一种基于mRNA的成本效益高的方法， 在FRT中表达抗精子抗体短期目标是优化方法， 机制问题，并证明在猕猴模型的临床前可行性。如果成功，新的 避孕的范例将被证明，一个可以与抗STI的共表达相结合的范例， 抗体，如针对HIV和HSV-2的抗体。

Project summary Currently 72% of women who practice contraception use hormonal methods, but there is frequent dissatisfaction with these methods, due to quality of life and safety concerns. Therefore, there is a clear need for new approaches to non-hormonal female contraceptives that are easy to use, woman-applied, and have a controllable duration of action. Reversible immunocontraception offers a non-hormonal solution, where anti- sperm antibodies are introduced into the female reproductive tract (FRT) and inhibit sperm function. This approach, though, has a number of challenges including: discovery of a specific and effective monoclonal antibody (mAb) against a human sperm antigen, and a safe and reliable method for introduction of mAbs that is temporally and spatially controllable. For this grant application, reproductive biology expertise and a molecular toolbox has been brought together to overcome these challenges. An anti-sperm antibody has been identified with well-characterized mechanisms of action that impact fertility, and an innovative method has been identified to deliver the antibody to the FRT. Here a synthetic mRNA-based approach is proposed to deliver a sperm agglutinating and mucus trapping antibody to the FRT. To date, the ability to express high levels of antibody for over 28 days with a single administration of mRNA in the FRT of sheep has been demonstrated. Delivery is achieved through direct, rapid, aerosol exposure of the FRT epithelium to naked mRNA in water. Persistence of the antibody in secretions was achieved through the incorporation of a GPI-linker into the heavy chain of the antibody. This combination allows for rapid delivery and expression, and for controllable persistence of the protective mAb in secretions. In the R61 phase, the mechanism of delivery under relevant conditions will be optimized and explored; antibody design questions will also be addressed that will allow for tunable persistence of the antibody in mucus secretions. In the R33 phase, pharmacokinetic experiments will be performed in macaques, as well as continued antibody optimization. Last, sperm challenge experiments will be performed in vivo to demonstrate efficacy. The long-term goal is to develop a cost-effective mRNA-based approach for expressing anti-sperm antibodies in the FRT. The short-term goals are to optimize the approach, answer mechanistic questions, and demonstrate pre-clinical feasibility in the macaque model. If successful, a new paradigm for contraception will be demonstrated, one that can be combined with the co-expression of anti-STI antibodies, such as those against HIV and HSV-2.