Department of Immunology and Allergy, Medical Research Institute, Alexandria University, Alexandria, Egypt.
Department of Microbiology & Medical Immunology, Faculty of Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt.
Egypt J Immunol. 2020 Jun;27(2):19-30.
Autoimmune hepatitis (AIH) is a heterogeneous immune-mediated chronic liver disease affecting children and adults. It is important to rely on a specific animal model to study the hepatic changes and to evaluate the roles played by pro-inflammatory cytokines such as tumor necrosis factor alpha "TNF-α" and transcription factors such as nuclear factor kappa-light-chain-enhancer of activated B cells "NF-κβ" in the pathogenesis and outcome of the disease. This will help to identify specific targets for treatment of AIH. This study aimed at evaluating Concanavalin-A (Con A) as a model for induction of AIH and assessing splenocytes' TNF-α and hepatocytes' NF-κβ levels at comparable durations after induction of hepatitis with Con A to evaluate the relationship between both factors. Materials and methods: A total of 130 outbreed CD1 mice were divided into group (1) which included 100 mice with induced AIH and group (2) included 30 normal mice as negative controls. Intra-peritoneal injection of Concanavalin-A was used to induce hepatitis. Hepatic injury was evaluated by the levels of liver enzymes, histopathological evidence for hepatic inflammatory infiltrate and/or apoptosis. Splenocytes and hepatocytes were cultured for assessment of TNF-α and NF-κβ levels, respectively. Results: Con A injection caused a significant elevation in ALT and AST levels, portal inflammatory infiltrate, remarkable hepatocytes degeneration and marked increase of TNF-α levels, particularly within 24 hours, but all returned to normal within 1 week. Administration of another dose of Con A resulted in sharp significant elevation of liver enzymes, inflammatory infiltrate and hepatocyte apoptosis after 24 hours and sustained till the end of the study. There was a significant increase in NF-κβ throughout most of the study duration following Con A injection as compared to that of normal mice. In conclusions, intra-peritoneal administration of Con A, particularly two doses, represents an efficient approach for induction of immune-mediated hepatitis. T-cells play a major role in AIH through release of TNF-α. Coincidently, hepatitis seems to be associated with elevation of NF-κβ to protect hepatocytes. Thus TNF-α and NF-κβ can represent targets for treatment of AIH either through inhibition or augmentation, respectively.
自身免疫性肝炎（AIH）是一种影响儿童和成人的异质性免疫介导的慢性肝脏疾病。依靠特定的动物模型来研究肝脏变化，并评估肿瘤坏死因子 alpha（TNF-α）等促炎细胞因子和核因子 kappa 轻链增强子的激活 B 细胞（NF-κβ）等转录因子在疾病发病机制和结局中的作用非常重要。这将有助于确定 AIH 的治疗特定靶点。本研究旨在评估刀豆蛋白 A（Con A）作为诱导 AIH 的模型，并在诱导 Con A 后相当长的时间内评估脾细胞 TNF-α和肝细胞 NF-κβ水平，以评估两者之间的关系。
共 130 只近交系 CD1 小鼠分为两组（1）包括 100 只诱导 AIH 的小鼠和（2）包括 30 只作为阴性对照的正常小鼠。腹腔注射 Concanavalin-A 诱导肝炎。通过肝酶水平、肝内炎症浸润和/或凋亡的组织病理学证据评估肝损伤。培养脾细胞和肝细胞分别评估 TNF-α和 NF-κβ水平。
Con A 注射导致 ALT 和 AST 水平、门脉炎症浸润、明显的肝细胞变性和 TNF-α水平显著升高，特别是在 24 小时内，但在 1 周内均恢复正常。给予另一种剂量的 Con A 后，24 小时后肝酶、炎症浸润和肝细胞凋亡明显显著升高，并持续至研究结束。与正常小鼠相比，Con A 注射后大多数研究时间内 NF-κβ水平显著升高。
腹腔内给予 Con A，特别是两次剂量，是诱导免疫介导性肝炎的有效方法。T 细胞通过释放 TNF-α在 AIH 中起主要作用。巧合的是，肝炎似乎与 NF-κβ的升高有关，以保护肝细胞。因此，TNF-α和 NF-κβ可以分别作为治疗 AIH 的靶点，通过抑制或增强来治疗。
