Development of the method for determinating ADCC biological activity of IVIG / 中国输血杂志

ABSTRACT

【Objective】 To establish a method for determinating the antigen-dependent cell-mediated cytotoxicity (ADCC) of human immunoglobulin (pH4)for intravenous injection (IVIG) on luciferase reporter gene-modified cell assay. 【Methods】 As effector cells, Jurkat-NFAT-Luc-CD16 cells were used in the assay, and PLC/PRF/5 cells were used as target cells. After incubation of effector cells and target cells with IVIG, the method for determinating ADCC biological activity of IVIG was established by detecting luciferase released by activated T nuclear factor after binding of IVIG Fc fragment to effector cells. Meanwhile, the experimental assay conditions were optimized, and the methodology was verified subsequently. 【Results】 IVIG had a dose-response relationship in this method, which was consistent with four parameter logistic model. And the PLC/PRF/5 cells were finally determined as the target cells. The initial dilution concentration of antibody was 20 mg/mL, and the ratio dilution was 1∶2, and the effector to target ratio was 1∶3, and co-incubation time of two cells and IVIG was 24 hours. Within-run and between-run analysis including three independent tests, initial working concentration relative light unit (RLU) and the relative standard deviation (RSD) of the concentration for 50% of maximal effect(EC50) were less than 11%. The relative titers of the recovery samples of the two different dilution groups were (23.50±1.69)% and (49.30±2.97)%, respectively, and the corresponding recovery rates were (93.50±6.30)% and (96.24±5.43)%, respectively, with RSD less than 11%. 【Conclusion】 The method for determinating ADCC biological activity of IVIG based on luciferase reporter gene-modified cell assay was successfully established. It could be applied in determinating the ADCC biological activity of IVIG, and has the advantages of satisfactory linearity, accuracy, precision and specificity.