Njoku Dolores B, Li Zhaoxia, Washington Nicole D, Mellerson Jenelle L, Talor Monica V, Sharma Rajni, Rose Noel R
Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
Eur J Immunol. 2009 Jun;39(6):1652-63. doi: 10.1002/eji.200838135.
The pathogenesis of immune-mediated drug-induced liver injury (DILI) following halogenated anesthetics, carbamazepine or alcohol has not been fully elucidated. Detecting cytochrome P450 2E1 (CYP2E1) IgG4 auto-antibodies in anesthetic DILI patients suggests a role for IL-4 in this hapten-mediated process. We investigated IL-4-mediated mechanisms using our model of experimental DILI induced by immunizing BALB/c (WT) and IL-4(-/-) (KO) mice with S100 liver proteins covalently modified by a trifluoroacetyl chloride (TFA) hapten formed following halogenated anesthetic metabolism by CYP2E1. WT mice developed more hepatitis, TFA and S100 antibodies (p<0.01), as well as T-cell proliferation to CYP2E1 and TFA (p<0.01) than KO mice. Additionally, WT CD4(+) T cells adoptively transferred hepatitis to naïve Rag(-/-) mice (p<0.01). Pro-inflammatory cytokines were expectedly decreased in TFA hapten-stimulated KO splenocyte supernatants (p<0.001); however, IL-2 and IFN-gamma (p<0.05), as well as IL-6 and IL-10 (p<0.001) levels were elevated in CYP2E1-stimulated KO splenocyte supernatants, suggesting dual IL-4-mediated pro-inflammatory and regulatory responses. Anti-IL-10 administered to KO mice increased hepatitis, TFA and CYP2E1 antibodies in KO mice confirming a critical role for IL-4. This is the first demonstration of dual roles for IL-4 in the pathogenesis of immune-mediated DILI by suppressing auto-antigen-induced regulatory responses while promoting hapten-induced pro-inflammatory responses.
卤代麻醉剂、卡马西平或酒精引发的免疫介导性药物性肝损伤（DILI）的发病机制尚未完全阐明。在麻醉性DILI患者中检测到细胞色素P450 2E1（CYP2E1）IgG4自身抗体，提示白细胞介素-4（IL-4）在这一半抗原介导过程中发挥作用。我们使用实验性DILI模型进行研究，该模型通过用经三氟乙酰氯（TFA）半抗原共价修饰的S100肝蛋白免疫BALB/c（野生型，WT）和IL-4基因敲除（KO）小鼠来诱导DILI，TFA半抗原是由CYP2E1对卤代麻醉剂进行代谢后形成的。与KO小鼠相比，WT小鼠出现了更严重的肝炎、TFA和S100抗体（p<0.01），以及针对CYP2E1和TFA的T细胞增殖（p<0.01）。此外，WT CD4(+) T细胞将肝炎转移至幼稚的Rag(-/-)小鼠（p<0.01）。不出所料，TFA半抗原刺激的KO脾细胞培养上清液中促炎细胞因子减少（p<0.001）；然而，CYP2E1刺激的KO脾细胞培养上清液中白细胞介素-2和干扰素-γ（p<0.05）以及白细胞介素-6和白细胞介素-10（p<0.001）水平升高，提示IL-4介导的双重促炎和调节反应。给KO小鼠注射抗白细胞介素-10会增加KO小鼠的肝炎、TFA和CYP2E1抗体，证实了IL-4的关键作用。这首次证明了IL-4在免疫介导性DILI发病机制中的双重作用，即抑制自身抗原诱导的调节反应，同时促进半抗原诱导的促炎反应。
