Nonclinical immunotoxicity evaluation is an important component of safety assessment for pharmaceuticals. One in vitro assay that can be applied in a weight of evidence assessment is the human lymphocyte activation (HuLA) assay, an antigen recall assay, similar in many respects to the in vivo T-cell-dependent antibody response (TDAR) in that cooperation of multiple immune cell types are needed to produce responses. This assay uses human cells and is more amenable than the TDAR to compound ranking and mechanistic studies. The HuLA assay requires less time and drug than TDAR assays, uses a relevant antigen (influenza), reflects a human immune response, and applies principles of the 3Rs to non-clinical safety assessment. Peripheral blood mononuclear cells (PBMC) from flu-immunized donors are re-stimulated with flu-vaccine in the presence of test articles, and proliferation is measured. Published data demonstrate the applicability of the HuLA assay, but it has not been evaluated for reproducibility across testing sites. To evaluate assay reproducibility, scientists from a consortium of institutions conducted the assay in parallel, using a common pool of donor PBMC, influenza vaccine, and known immunosuppressant compounds (cyclosporine A and mycophenolic acid). The HuLA assay was highly reproducible in identification of inhibition of antigen-specific responses, and there was significant agreement across testing sites in the half maximal inhibitory concentration (IC50) values. Intra-site variability was the largest contributor to the variability observed within the assay. The HuLA assay was demonstrated to be ideally suited to comparing multiple compounds (i.e. compound ranking or benchmarking) within the same assay. Overall, the data reported herein support the HuLA assay as a useful tool in mechanistic evaluations of antigen-specific immune responses.

中文翻译：

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跨公司评估人类淋巴细胞激活测定。

非临床免疫毒性评估是药物安全性评估的重要组成部分。可以用于证据评估的一种体外测定方法是人淋巴细胞激活（HuLA）测定法，一种抗原召回测定法，在许多方面与体内T细胞依赖性抗体应答（TDAR）相似，需要多种免疫细胞类型来产生应答。该测定法使用人类细胞，比TDAR更适合进行化合物分级和机理研究。与TDAR分析相比，HuLA分析所需的时间和药物更少，使用相关抗原（流感），反映了人类的免疫反应，并将3R原理应用于非临床安全性评估。在测试物品的存在下，用流感疫苗重新刺激来自流感免疫供体的外周血单核细胞（PBMC），并测量增殖。已发布的数据证明了HuLA测定法的适用性，但尚未评估其在各个测试部位的可重复性。为了评估测定的可重复性，来自一个机构协会的科学家使用共同的供体PBMC，流感疫苗和已知的免疫抑制剂化合物（环孢菌素A和霉酚酸）平行进行了测定。HuLA分析在鉴定抗原特异性反应的抑制作用方面具有很高的可重复性，并且在测试位点之间的最大最大抑制浓度（IC50）值达到了一半。站点内变异性是导致分析中观察到的变异性最大的因素。事实证明，HuLA分析非常适合在同一分析中比较多种化合物（即化合物排名或基准）。总的来说，本文报道的数据支持HuLA测定法作为抗原特异性免疫应答的机械评价中的有用工具。