Signorazzi Aurora, Etna Marilena P, Coccia Eliana M, Huckriede Anke
Department of Medical Microbiology & Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy.
ALTEX. 2021;38(3):431-441. doi: 10.14573/altex.2010081. Epub 2021 Jan 13.
Tick-borne encephalitis (TBE) virus causes a severe disease that can lead to permanent neurological complications. The whole inactivated TBE vaccine is highly effective, as proven by high seroconversion rates and near eradication of the disease in countries where vaccination programs have been implemented. TBE vaccine potency testing currently requires the use of in vivo methods that present issues of reproducibility as well as animal discomfort. As an alternative, public and private entities are currently exploring a batch-to-batch consistency approach that would demonstrate conformity of a newly produced vaccine batch with a batch of proven in vivo efficacy with respect to a range of measurable in vitro quality parameters. To identify a suitable cellular platform to be used in a panel of in vitro batch-to-batch assessments for the TBE vaccine, we exposed human cell-based systems, both of primary origin and cell line-derived, to vaccine formulations of high and low quality. Following stimulation, cell responses were evaluated by assessing the expression of selected genes by RT-qPCR. Our findings show that the expression of interferon-stimulated genes differed after treatment with non-adjuvanted vaccine batches of different quality in peripheral blood mononuclear cells (PBMCs) and in monocyte-derived dendritic cells, but not in monocyte-free PBMC suspensions nor in cell line-derived immune cells. These results indicate suitable platforms and potential biomarkers for a cell-based assay that, together with other immunochemical analyses, could serve for batch-to-batch assessment of the TBE vaccine, reducing, and eventually replacing, in vivo methods for potency testing.
蜱传脑炎（TBE）病毒可引发严重疾病，导致永久性神经并发症。全灭活TBE疫苗非常有效，在实施疫苗接种计划的国家，高血清转化率和该疾病近乎根除的情况证明了这一点。目前，TBE疫苗效力测试需要使用体内方法，这些方法存在可重复性问题以及动物不适的问题。作为替代方案，公共和私营实体目前正在探索一种批次间一致性方法，该方法将证明新生产的疫苗批次在一系列可测量的体外质量参数方面与一批已证明具有体内效力的批次相符。为了确定用于TBE疫苗体外批次间评估的合适细胞平台，我们将原代来源和细胞系来源的基于人类细胞的系统暴露于高质量和低质量的疫苗制剂中。刺激后，通过RT-qPCR评估选定基因的表达来评估细胞反应。我们的研究结果表明，用不同质量的无佐剂疫苗批次处理后，外周血单核细胞（PBMC）和单核细胞衍生的树突状细胞中干扰素刺激基因的表达有所不同，但在无单核细胞的PBMC悬浮液或细胞系来源的免疫细胞中则没有差异。这些结果表明了基于细胞的检测的合适平台和潜在生物标志物，这些平台和生物标志物与其他免疫化学分析一起，可用于TBE疫苗的批次间评估，减少并最终取代体内效力测试方法。
