目的 研究中药制剂毛萼乙素（EriB）对免疫球蛋白类别转换（CSR）的作用。方法 以不同剂量的EriB （0、0.75、1.5和2.0 μmol/L）处理脂多糖（LPS）刺激下的B淋巴细胞系1B4.B6细胞，采用MTT和流式细胞术检测细胞的生长状态，并分别采用ELISA、RT-PCR和Western blotting方法检测免疫球蛋白的产生及其CSR的效率以及CSR相关基因的表达水平，采用报告基因法检测EriB对NF-κB的转录调控作用。结果 随着EriB浓度的升高，B细胞增殖及CSR均出现障碍。进一步实验证实EriB通过抑制IKKα的活性阻断IκB磷酸化，进而抑制NF-κB1活化入核；同时直接抑制NF-κB1的转录从而导致其表达水平降低。结论 EriB可通过NF-κB信号通路抑制CSR的发生。

Objective To investigate the effects of Eriocalyxin B (EriB) on immunoglobulin class switch recombination (CSR). Methods B lymphocytes (1B4.B6) were treated with lipopolysaccharide (LPS) and different doses (0 μmol/L, 0.75 μmol/L, 1.5 μmol/L and 2.0 μmol/L) of EriB, the proliferation of these cells was analyzed by MTT and flow cytometry, the generation of immunoglobulin, efficiency of CSR and expression of relevant genes which play important roles in CSR were examined by ELISA, RT-PCR and Western blotting respectively, and the regulation of NF-κB transcription via EriB was determined by luciferase assay. Results With the increase of EriB concentration, the proliferation and CSR of B cells were defective. EriB inhibited the activation of NF-κB1 through blocking IκBα phosphorylation and degradation. It also directly repressed the transcription level of NF-κB1. Conclusion EriB could inhibit CSR through repressing the activation of NF-κB signaling pathway.