Scalable production of recombinant protein microbicides

说明（由申请人提供）：HIV杀菌剂设计用于在性交前局部使用，以灭活病毒并防止感染。一些最有前途的杀菌剂候选是蛋白质，但由于缺乏可用材料和/或必须以非常低的成本制造大量重组蛋白质的前景，它们的临床开发和评估受到阻碍。植物生物技术提供了一些潜在的解决方案。虽然以农业规模生产杀菌剂是一个长期目标，但第一代产品很可能来自在封闭环境中生长的植物，在更可识别为传统药物生产系统的条件下。重组蛋白可以在植物的所有组织中表达，包括根。事实上，转基因植物产生的一些重组蛋白在一个被称为根分泌的过程中积极地从根系分泌出来。这就产生了转基因植物可以在温室中水培条件下生长的可能性，使用特定的培养基。此外，杀菌剂产品可以从水培培养基中收获，而不是从植物组织中收获，这将大大简化纯化过程，并允许在植物的整个生命周期中收获。水培栽培植物在园艺工业中已经是一项成熟的技术，目前也用于生产天然药用化合物。本提案的目的是建立一种含水培烟草植物培养方法，用于生产两种杀微生物剂候选蛋白cyanovirin-N和MAb 4E10，并制定生长和生产的优化策略，以提供以前无法获得的杀微生物剂蛋白，以达到临床评估的水平。我们将建立小规模的商业生产。在提案的第一阶段（R21），我们打算证明该方法的可行性，并为进入第二阶段（R33）建立生产驱动的里程碑，在第二阶段，我们将根据良好实践监管要求开发生产和纯化，最终为临床试验提供蛋白质杀微生物剂。Cyanovirin-N和MAb 4E10是目前最有前途的两种蛋白质杀微生物剂候选药物。然而，由于生产困难，这两种药物的临床开发一直受到阻碍，其疗效和安全性仍有待确定。该项目旨在开发CV-N、MAb 4E10和其他重组蛋白杀微生物剂的生产平台，将这些产品推进人体临床试验。

DESCRIPTION (provided by applicant): HIV microbicides are designed to be applied topically before sexual intercourse to inactivate the virus and prevent infection. Some of the most promising microbicide candidates have been proteins, but their clinical development and evaluation has been hampered by the lack of available material and/or the prospect of having to manufacture vast quantities of recombinant protein very cheaply. Plant biotechnology offers some potential solutions. Whilst the production of microbicides at agricultural scale is a long term aim, it is likely that the first generation products will emerge from plants grown in containment, under conditions more recognizable as conventional medicine production systems. It has long been established that recombinant proteins can be expressed in all tissues of the plant, including roots. Indeed, some recombinant proteins produced by transgenic plants are actively secreted from the root system in a process known as rhizosecretion. This gives rise to the possibility that transgenic plants could be grown in greenhouses under hydroponic conditions, using a defined culture medium. Moreover, the microbicide product could be harvested from hydroponic culture medium, rather than plant tissue, which would greatly simplify purification, and allow harvest over the lifetime of the plant. Hydroponic cultivation of plants is already a well established technique in the horticultural industry and is also currently used for the production of natural medicinal compounds. The objective of this proposal is to establish a contained hydroponic tobacco plant culture approach for production of two microbicide protein candidates, cyanovirin-N and MAb 4E10, and to develop optimization strategies for growth and production that will deliver previously unavailable protein microbicides at a level to allow clinical evaluation. We will establish production at small commercial scale. In the first (R21) phase of the proposal, we intend to demonstrate feasibility of the approach and have established production driven milestones for entry into the second (R33) phase, in which we will develop manufacturing and purification according to Good Practice regulatory requirements ultimately to deliver protein microbicides for clinical trials. Cyanovirin-N and MAb 4E10 are two of the most promising protein microbicide candidates currently available. However, the clinical development of both has been held back by production difficulties, and their efficacy and safety profiles are still to be determined. This project is aimed at developing a production platform for CV-N, MAb 4E10 and ultimately other recombinant protein microbicides, that will advance these products to human clinical trials.