通过N4BP1的caspase-8裂变整合先天免疫信号
Alexander D Gitlin1,2, Klaus Heger3, Alexander F Schubert4
1Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA. adgitlin@stanford.edu.
Nature
|September 24, 2020
概括
NEDD4结合蛋白1 (N4BP1) 抑制了细胞因子的产生,并被卡斯巴酶8禁用. 通过酶-8的分裂整合了炎症信号,解释了与酶-8突变相关的免疫缺陷.
科学领域:
- 免疫学
- 分子生物学
- 细胞信号传输
背景情况:
- FAS,FASL,caspase-8或FADD的突变与自身免疫淋巴增殖综合征和严重免疫缺陷有关.
- 与FADD-caspase-8通路缺陷相关的免疫缺陷的确切机制尚不清楚.
- 在免疫反应和细胞死亡途径中发挥关键作用.
研究的目的:
- 确定参与免疫反应的细胞因子生产的新型调节剂.
- 阐明NEDD4结合蛋白1 (N4BP1) 在调节炎症信号中的作用.
- 了解酶-8活性如何影响N4BP1功能和细胞因子的产生.
主要方法:
- 使用针对基因删除的小鼠模型 (N4BP1,caspase-8).
- 刺激巨细胞中的托尔类受体 (TLRs) 1/ 2, 3, 4, 7 和 9.
- 对各种刺激和遗传修饰的反应评估了细胞因子的产生和N4BP1裂变.
主要成果:
- 鉴定出N4BP1是细胞因子生产的抑制剂,通过caspase-8裂变失活.
- 通过TLR1/2,TLR7和TLR9增强N4BP1删除细胞因子的产生,而不是TLR3或TLR4.
- 对于强大的细胞因子对TLR3和TLR4刺激以及TNF信号的反应,需要使用卡斯巴酶-8依赖的N4BP1裂变.
结论:
- 作为细胞因子反应的强有力的抑制剂.
- N4BP1的Caspase-8介导裂变是炎症信号的关键整合点.
- 这种机制解释了在FADD和caspase-8突变患者中观察到的免疫缺陷.
相关概念视频
Caspases
13.3K
Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside...
13.3K
The Extrinsic Apoptotic Pathway
7.6K
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
7.6K
The Intrinsic Apoptotic Pathway
7.8K
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
7.8K
NF-κB-dependent Signaling Pathway
9.5K
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
NF-κB-dependent Signaling Mechanism
The...
9.5K
Apoptosis
13.3K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
13.3K
Phagocytosis of Apoptotic Cells
4.5K
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized...
Normal cells contain receptors that prevent them from being recognized...
4.5K


