Pfizer Inc, Groton, CT, USA.
Health and Environmental Sciences Institute, Washington, DC, USA.
J Immunotoxicol. 2020 Dec;17(1):51-58. doi: 10.1080/1547691X.2020.1725694.
Nonclinical immunotoxicity evaluation is an important component of safety assessment for pharmaceuticals. One 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 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 (IC) 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.
非临床免疫毒性评价是药物安全性评估的重要组成部分。一种可用于证据综合评估的方法是人类淋巴细胞激活（HuLA）测定，这是一种抗原回忆测定，在许多方面与 T 细胞依赖性抗体反应（TDAR）相似，因为需要多种免疫细胞类型的合作才能产生反应。该测定法使用人细胞，比 TDAR 更适合于化合物分级和机制研究。HuLA 测定法所需的时间和药物比 TDAR 测定法少，使用相关抗原（流感），反映了人类的免疫反应，并将 3R 原则应用于非临床安全性评估。来自流感免疫供体的外周血单核细胞（PBMC）在用测试药物再刺激流感疫苗的情况下进行增殖测量。已发表的数据证明了 HuLA 测定法的适用性，但尚未在不同的测试地点评估其重现性。为了评估测定法的重现性，来自机构联盟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）进行平行测定，从而评估了测定法的重现性。HuLA 测定法在识别抑制抗原特异性反应方面具有高度的重现性，并且在不同的测试地点之间在半最大抑制浓度（IC）值方面存在显著的一致性。站点内的变异性是观察到的测定内变异性的最大贡献者。HuLA 测定法被证明非常适合于在同一测定中比较多种化合物（即化合物分级或基准测试）。总体而言，本文报告的数据支持 HuLA 测定法作为评估抗原特异性免疫反应的机制的有用工具。
