St Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY10065, USA.
J Allergy Clin Immunol. 2011 Sep;128(3):610-7.e1-4. doi: 10.1016/j.jaci.2011.04.059. Epub 2011 Jul 1.
Children with germline mutations in Toll-like receptor 3 (TLR3), UNC93B1, TNF receptor-associated factor 3, and signal transducer and activator of transcription 1 are prone to herpes simplex virus-1 encephalitis, owing to impaired TLR3-triggered, UNC-93B-dependent, IFN-α/β, and/or IFN-λ-mediated signal transducer and activator of transcription 1-dependent immunity.
We explore here the molecular basis of the pathogenesis of herpes simplex encephalitis in a child with a hypomorphic mutation in nuclear factor-κB (NF-κB) essential modulator, which encodes the regulatory subunit of the inhibitor of the Iκβ kinase complex.
The TLR3 signaling pathway was investigated in the patient's fibroblasts by analyses of IFN-β, IFN-λ, and IL-6 mRNA and protein levels, by quantitative PCR and ELISA, respectively, upon TLR3 stimulation (TLR3 agonists or TLR3-dependent viruses). NF-κB activation was assessed by electrophoretic mobility shift assay and interferon regulatory factor 3 dimerization on native gels after stimulation with a TLR3 agonist.
The patient's fibroblasts displayed impaired responses to TLR3 stimulation in terms of IFN-β, IFN-λ, and IL-6 production, owing to impaired activation of both NF-κB and IRF-3. Moreover, vesicular stomatitis virus, a potent IFN-inducer in human fibroblasts, and herpes simplex virus-1, induced only low levels of IFN-β and IFN-λ in the patient's fibroblasts, resulting in enhanced viral replication and cell death, as reported for UNC-93B-deficient fibroblasts.
Herpes simplex encephalitis may occur in patients carrying NF-κB essential modulator mutations, due to the impairment of NF-κB- and interferon regulatory factor 3-dependent-TLR3-mediated antiviral IFN production.
由于 Toll 样受体 3（TLR3）、UNC93B1、肿瘤坏死因子受体相关因子 3 和信号转导和转录激活因子 1 的种系突变，儿童易患单纯疱疹病毒 1 脑炎，因为 TLR3 触发的 UNC-93B 依赖性 IFN-α/β 和/或 IFN-λ 介导的信号转导和转录激活因子 1 依赖性免疫受损。
我们在这里探索核因子-κB（NF-κB）必需调节剂（编码 Iκβ 激酶复合物抑制剂的调节亚基）的低功能突变儿童单纯疱疹脑炎发病机制的分子基础。
通过 IFN-β、IFN-λ 和 IL-6 mRNA 和蛋白水平的分析，分别通过定量 PCR 和 ELISA，在患者的成纤维细胞中研究 TLR3 信号通路，在 TLR3 刺激（TLR3 激动剂或 TLR3 依赖性病毒）后。通过 TLR3 激动剂刺激后的电泳迁移率变动分析和天然凝胶上的干扰素调节因子 3 二聚化评估 NF-κB 激活。
由于 NF-κB 和 IRF-3 的激活受损，患者的成纤维细胞在 IFN-β、IFN-λ 和 IL-6 产生方面对 TLR3 刺激的反应受损。此外，水疱性口炎病毒，一种有效的人成纤维细胞 IFN 诱导剂，以及单纯疱疹病毒 1，仅在患者的成纤维细胞中诱导低水平的 IFN-β 和 IFN-λ，导致病毒复制和细胞死亡增强，如 UNC-93B 缺陷型成纤维细胞报道的那样。
由于 NF-κB 和干扰素调节因子 3 依赖性 TLR3 介导的抗病毒 IFN 产生受损，NF-κB 必需调节剂突变的患者可能发生单纯疱疹脑炎。
