Engineering bispecific antibodies for non-hormonal contraception

用于非激素避孕的双特异性抗体工程

基本信息

批准号：
10618849
负责人：
Samuel Lai
金额：
$ 49.38万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10618849
关键词：
Acceleration Affinity Agglutination Anatomy Animal Model Antibodies Antibody Formation Antigen Targeting Antigens Binding Biological Assay Bispecific Antibodies Boston Cells Cervix Mucus Clinical Trials Computer Assisted Contraceptive Agents Contraceptive Vaccines Contraceptive methods Deposition Development Dose Embryo Engineering Enzyme-Linked Immunosorbent Assay Fab domain Federal Government Fertility Formulation Histopathology Human Immune Immunoglobulin G Immunoglobulin M Immunologic Contraception Individual Infertility Inflammation Inflammatory Kinetics Lead Libraries Link Macaca Male Genital Organs Measures Methods Modeling Monoclonal Antibodies Mucins Mucous body substance Oocytes Oryctolagus cuniculus Parents Passive Immunization Penetration Phase I Clinical Trials Pilot Projects Polymers Production Protease Inhibitor Research Sampling Seminal fluid Sheep Specificity Sperm Agglutination Sperm Motility Spermatozoa antibody State Government Surface Surface Antigens Swimming Technology Testing Tight Junctions Time Tissues Universities Vaccines Vagina Vaginal Ring Vaginal delivery procedure Woman Yeasts Zona Pellucida antibody engineering bioprocess cell motility cervicovaginal contraceptive efficacy contraceptive target cost crosslink cytokine gel electrophoresis genital secretion improved in vivo manufacture next generation novel pathogen pre-clinical assessment prevent reproductive tract reversible contraceptive safety assessment sperm analysis sperm cell unintended pregnancy vaccine response zygote

项目摘要

Summary Sperm must swim through mucus before ascending to the upper tract and fertilizing the egg. In addition, sperm must be hyperactivated to penetrate the zona pellucida of the oocyte. Polymeric antibodies (Ab) such as IgM that bind sperm surface antigens can agglutinate sperm into clusters too large to penetrate through the pores of mucus. In addition, IgG can also be engineered to crosslink individual sperm to mucins, as well as inhibit hyperactivation, consequently preventing sperm from reaching and fertilizing the egg. Topical passive immunization based on vaginal delivery of anti-sperm Ab (ASA) was validated in animal models in the 1980s-1990s, and directly overcomes the variable intensity and uncertain reversibility of contraceptive vaccines. However, this strategy was not practical due to the high costs of mAb production and challenges with IgM formulation. Given the remarkable advances in bioprocessing that have greatly reduced the costs of mAb manufacturing, and the possibility of sustained delivery of antibodies in the vagina via intravaginal rings, we believe the time is now ripe to develop novel, ultra-potent ASA for non-hormonal contraception based on topical passive immunization of the vagina against human sperm. In pilot studies, we have shown that we can greatly increase the sperm-agglutination potency of ASA by >15-50-fold by engineering multivalent, IgG-based construct comprised of six to ten Fab domains (i.e. 4 to 8 additional Fabs linked to the parent IgG molecule). These novel constructs possess comparable stability to IgG in accelerated thermal stability studies, and also similar production and purification yield as IgG. One of the constructs represent the lead molecule under development in the Boston University Contraceptive Research Center, with two Phase I clinical trials slated to begin in 2020. In this project, we seek to further improve the potencies by employing cutting edge bispecific Ab engineering technology and affinity maturation via yeast and mamallian cell display to engineer a library of ultra-potent bispecific multivalent ASA constructs. We will target both CD52g, a well characterized and validated antigen target present on human sperm only, and EPPIN, a well established contraceptive target that functions by inhibiting sperm hyperactivation. In Aim 1, we will utilize yeast display to improve the affinity of Fab against CD52g and EPPIN, engineer a library of multivalent bispecific constructs that bind both targets, and rigorously characterize these molecules. In Aim 2, we will perform a panel of studies to assess their potential contraceptive efficacy, including sperm agglutination, trapping individual sperm in mucus, and inhibition of sperm hyperactivation. To determine which construct will most effectively reduce progressive sperm motility in human vagina, we will perform in vivo dose finding studies in Aim 3 with the two most potent constructs from Aims 1 and 2 in a post-coital fertility test adapted to the sheep vagina. Successful completion of these studies will likely allow us to advance a novel ASA candidate with substantially greater contraceptive potency than the current ASA molecules under development for non-hormonal contraception.

概括精子必须在粘液上游泳，然后再升至上卵并施肥。另外，精子必须过度活化以穿透卵母细胞的zona卵黄。聚合物抗体（AB），例如IgM 结合精子表面抗原可以将精子凝结成太大而无法穿透孔的簇粘液。此外，IgG还可以设计为交联单个精子到粘蛋白，并抑制过度激活，因此阻止了精子到达和施肥。局部被动基于阴道递送抗植物AB（ASA）的免疫接种在动物模型中验证 1980年代至1990年代，直接克服了避孕的可变强度和不确定的可逆性疫苗。但是，由于MAB生产和挑战的高成本，该策略是不切实际的具有IGM公式。鉴于生物处理的显着进步大大降低了成本 MAB制造以及通过腔内持续在阴道中持续传递抗体的可能性戒指，我们认为现在的时间已经成熟，可以开发出用于非激素避孕的新颖，超功能的ASA 基于阴道对人类精子的局部被动免疫。在试点研究中，我们表明通过工程学，我们可以大大提高ASA的精子 - 凝集效力> 15-50倍多价，基于IgG 父级IgG分子）。这些新型构建体具有与IgG相当的稳定性稳定性研究，以及与IgG相似的产生和纯化产量。其中一种构造代表波士顿大学避孕研究中心正在开发的铅分子，有两个I期临床试验定于2020年开始。在这个项目中，我们寻求通过采用前沿双特异性AB工程技术和通过酵母和Mamallian细胞显示的亲和力成熟设计超功效双特异性多价ASA构建体的库。我们将瞄准两个CD52G 仅在人类精子上表征和验证的抗原靶标，而Eppin是一个已建立的通过抑制精子过度激活来起作用的避孕目标。在AIM 1中，我们将利用酵母展示改善Fab与CD52G和Eppin的亲和力，工程师的多价双特异性构造库结合两个靶标，并严格地表征这些分子。在AIM 2中，我们将执行一个面板评估其潜在避孕功效的研究，包括精子凝集，诱捕单个精子在粘液中，抑制精子过度激活。确定哪种结构最有效地减少在人类阴道中进行性精子运动，我们将在AIM 3中进行体内剂量研究研究。 AIMS 1和2的大多数有效的结构都适用于羊皮阴道。成功的这些研究的完成可能会使我们能够促进一个大大更大的新颖ASA候选者避孕效力比目前正在开发的非激素避孕的ASA分子。