开发和评估一种新的恶性疟原虫 3D7 血期疟原虫细胞库，用于疟疾志愿者感染研究。
Development and evaluation of a new Plasmodium falciparum 3D7 blood stage malaria cell bank for use in malaria volunteer infection studies.
机构信息
QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
Centre for Defence Pathology, Royal Centre for Defence Medicine, Joint Hospital Group, ICT Building, Birmingham Research Park, Vincent Drive, Birmingham, UK.
出版信息
Malar J. 2021 Feb 16;20(1):93. doi: 10.1186/s12936-021-03627-z.
BACKGROUND
New anti-malarial therapeutics are required to counter the threat of increasing drug resistance. Malaria volunteer infection studies (VIS), particularly the induced blood stage malaria (IBSM) model, play a key role in accelerating anti-malarial drug development. Supply of the reference 3D7-V2 Plasmodium falciparum malaria cell bank (MCB) is limited. This study aimed to develop a new MCB, and compare the safety and infectivity of this MCB with the existing 3D7-V2 MCB, in a VIS. A second bank (3D7-V1) developed in 1995 was also evaluated.
METHODS
The 3D7-V2 MCB was expanded in vitro using a bioreactor to produce a new MCB designated 3D7-MBE-008. This bank and 3D7-V1 were then evaluated using the IBSM model, where healthy participants were intravenously inoculated with blood-stage parasites. Participants were treated with artemether-lumefantrine when parasitaemia or clinical thresholds were reached. Safety, infectivity and parasite growth and clearance were evaluated.
RESULTS
The in vitro expansion of 3D7-V2 produced 200 vials of the 3D7-MBE-008 MCB, with a parasitaemia of 4.3%. This compares to 0.1% in the existing 3D7-V2 MCB, and < 0.01% in the 3D7-V1 MCB. All four participants (two per MCB) developed detectable P. falciparum infection after inoculation with approximately 2800 parasites. For the 3D7-MBE-008 MCB, the parasite multiplication rate of 48 h (PMR) using non-linear mixed effects modelling was 34.6 (95% CI 18.5-64.6), similar to the parental 3D7-V2 line; parasitaemia in both participants exceeded 10,000/mL by day 8. Growth of the 3D7-V1 was slower (PMR of 11.5 [95% CI 8.5-15.6]), with parasitaemia exceeding 10,000 parasites/mL on days 10 and 8.5. Rapid parasite clearance followed artemether-lumefantrine treatment in all four participants, with clearance half-lives of 4.01 and 4.06 (weighted mean 4.04 [95% CI 3.61-4.57]) hours for 3D7-MBE-008 and 4.11 and 4.52 (weighted mean 4.31 [95% CI 4.16-4.47]) hours for 3D7-V1. A total of 59 adverse events occurred; most were of mild severity with three being severe in the 3D7-MBE-008 study.
CONCLUSION
The safety, growth and clearance profiles of the expanded 3D7-MBE-008 MCB closely resemble that of its parent, indicating its suitability for future studies.
TRIAL REGISTRATION
Australian New Zealand Clinical Trials registry numbers: P3487 (3D7-V1): ACTRN12619001085167. P3491 (3D7-MBE-008): ACTRN12619001079134.
背景
需要新的抗疟疗法来应对日益增加的耐药性威胁。疟疾志愿者感染研究（VIS），特别是诱导的血液期疟疾（IBSM）模型，在加速抗疟药物开发方面发挥着关键作用。参考 3D7-V2 恶性疟原虫疟疾细胞库（MCB）的供应有限。本研究旨在开发一种新的 MCB，并在 VIS 中比较现有 3D7-V2 MCB 的安全性和感染力。还评估了 1995 年开发的第二个库（3D7-V1）。
方法
使用生物反应器在体外扩增 3D7-V2 MCB，产生新的 MCB，命名为 3D7-MBE-008。然后使用 IBSM 模型评估这两个库和 3D7-V1，健康参与者通过静脉内接种血液期寄生虫。当寄生虫血症或临床阈值达到时，参与者用青蒿琥酯-咯萘啶治疗。评估安全性、感染力和寄生虫生长及清除情况。
结果
3D7-V2 的体外扩增产生了 200 瓶 3D7-MBE-008 MCB，寄生虫血症为 4.3%。这与现有 3D7-V2 MCB 的 0.1%和 3D7-V1 MCB 的<0.01%相比。所有四名参与者（每个 MCB 两名）在接种约 2800 个寄生虫后均出现可检测到的恶性疟原虫感染。对于 3D7-MBE-008 MCB，使用非线性混合效应模型的 48 小时寄生虫倍增率（PMR）为 34.6（95%CI 18.5-64.6），与亲本 3D7-V2 系相似；两名参与者的寄生虫血症均在第 8 天超过 10,000/mL。3D7-V1 的生长速度较慢（PMR 为 11.5 [95%CI 8.5-15.6]），第 10 天和第 8.5 天寄生虫血症超过 10,000 个寄生虫/毫升。青蒿琥酯-咯萘啶治疗后，所有四名参与者的寄生虫迅速清除，3D7-MBE-008 和 3D7-V1 的清除半衰期分别为 4.01 和 4.06（加权平均值 4.04 [95%CI 3.61-4.57]）小时和 4.11 和 4.52（加权平均值 4.31 [95%CI 4.16-4.47]）小时。共发生 59 起不良事件；大多数为轻度严重程度，3 起为 3D7-MBE-008 研究中的重度。
结论
扩增的 3D7-MBE-008 MCB 的安全性、生长和清除情况与其亲本非常相似，表明其适合未来的研究。
试验注册
澳大利亚和新西兰临床试验注册编号：P3487（3D7-V1）：ACTRN12619001085167。P3491（3D7-MBE-008）：ACTRN12619001079134。
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