Scalable production of recombinant protein microbicides

描述(申请人提供)：艾滋病毒杀微生物剂被设计用于性交前的局部应用，以灭活病毒并防止感染。一些最有希望的杀微生物剂候选是蛋白质，但由于缺乏可用的材料和/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了阻碍。植物生物技术提供了一些潜在的解决方案。虽然农业规模的杀菌剂生产是一个长期目标，但第一代产品很可能会在更容易被识别为传统药物生产系统的条件下，从密闭种植的植物中产生。长期以来，人们已经证实，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种称为根分泌的过程中从根系统中活跃地分泌出来。这使得转基因植物有可能在水培条件下的温室里种植，使用特定的培养介质。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，这将极大地简化纯化，并允许在植物的整个生命周期内进行收获。水培栽培植物在园艺业中已经是一项成熟的技术，目前也被用于生产天然药物化合物。这项提议的目的是建立一种水培烟草植物培养方法，用于生产两种候选杀微生物剂蛋白质-氰化韦林-N和单抗4E10，并制定生长和生产的优化战略，以提供以前无法获得的蛋白质杀菌剂，以便进行临床评估。我们将建立小型商业规模的生产。在提案的第一阶段(R21)，我们打算证明该方法的可行性，并已建立了进入第二阶段(R33)的生产驱动里程碑，在该阶段中，我们将根据良好实践监管要求发展制造和纯化，最终为临床试验提供蛋白质杀菌剂。氰韦林-N和单抗4E10是目前最有前景的两种蛋白质类杀菌剂。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。该项目旨在开发一个用于CV-N、单抗4E10以及最终其他重组蛋白杀菌剂的生产平台，从而将这些产品推向人体临床试验。

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.