Background Influenza viruses cause hundreds of thousands of respiratory diseases worldwide each year, and vaccination is considered the most effective approach for preventing influenza annual epidemics or pandemics. Since 1950, chicken embryonated eggs have been used as the main method for producing seasonal influenza vaccines. However, this platform has the main drawback of a lack of scale-up flexibility, and thus, egg-based vaccine manufacturers cannot supply sufficient doses within a short period for use for pandemic prevention. As a result, strategies for reducing the manufacturing time and increasing production capacity are urgently needed. Non-virion vaccine methods have been considered an alternative strategy against an influenza pandemic, and the purpose of maintaining an immunogenic capsule structure with infectious properties appears to be met by the virus-like particle (VLP) platform. Results An influenza H7N9-TW VLP production platform using insect cells, which included the expression of hemagglutinin (HA), NA, and M1 proteins, was established. To scale up H7N9-TW VLP production, several culture conditions were optimized to obtain a higher production yield. A high level of dissolved oxygen (DO) could be critical to H7N9-TW VLP production. If the DO was maintained at a high level, the HA titer obtained in the spinner flask system with ventilation was similar to that obtained in a shake flask. In this study, the HA titer in a 5-L bioreactor with a well-controlled DO level was substantially improved by 128-fold (from 4 HA units (HAU)/50 μL to 512 HAU/50 μL). Conclusions In this study, a multigene expression platform and an effective upstream process were developed. Notably, a high H7N9-TW VLP yield was achieved using a two-step production strategy while a high DO level was maintained. The upstream process, which resulted in high VLP titers, could be further used for large-scale influenza VLP vaccine production.

中文翻译：

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使用杆状病毒表达系统生产大流行性流感 VLP 疫苗的工艺开发。

背景流感病毒每年在全世界引起数十万种呼吸道疾病，疫苗接种被认为是预防流感年度流行或大流行的最有效方法。自1950年以来，鸡胚蛋一直作为生产季节性流感疫苗的主要方法。然而，该平台的主要缺点是缺乏扩大规模的灵活性，因此，以鸡蛋为基础的疫苗制造商无法在短期内提供足够的剂量用于大流行预防。因此，迫切需要减少制造时间和提高生产能力的策略。非病毒疫苗方法已被认为是对抗流感大流行的替代策略，病毒样颗粒（VLP）平台似乎可以满足维持具有传染性的免疫原性胶囊结构的目的。结果建立了以昆虫细胞为载体的H7N9-TW VLP生产平台，包括血凝素（HA）、NA和M1蛋白的表达。为了扩大 H7N9-TW VLP 的生产，优化了几种培养条件以获得更高的产量。高水平的溶解氧 (DO) 可能对 H7N9-TW VLP 的生产至关重要。如果 DO 保持在高水平，则在具有通风的旋转烧瓶系统中获得的 HA 滴度与在摇瓶中获得的相似。在这项研究中，DO 水平得到良好控制的 5-L 生物反应器中的 HA 滴度显着提高了 128 倍（从 4 个 HA 单位 (HAU)/50 μL 到 512 HAU/50 μL）。结论 在本研究中，开发了多基因表达平台和有效的上游工艺。值得注意的是，使用两步生产策略实现了高 H7N9-TW VLP 产量，同时保持了高 DO 水平。导致高 VLP 滴度的上游工艺可进一步用于大规模流感 VLP 疫苗生产。