CD19 is a type I transmembrane glycoprotein of the immunoglobulin superfamily, serving as a B cell-specific marker. It is continuously expressed throughout B cell development but disappears upon terminal differentiation into plasma cells. As it lacks intrinsic kinase activity, CD19 needs to form a B cell co-receptor complex with proteins such...
CD19 is a type I transmembrane glycoprotein of the immunoglobulin superfamily, serving as a B cell-specific marker. It is continuously expressed throughout B cell development but disappears upon terminal differentiation into plasma cells. As it lacks intrinsic kinase activity, CD19 needs to form a B cell co-receptor complex with proteins such as CD21 and CD81 to function. Acting as a co-receptor for the B cell receptor (BCR), when the BCR recognizes an antigen, CD19 cooperates to bring the antigen protein closer and strengthens binding. It then rapidly activates kinases like Lyn, which are connected to its intracellular domain, while powerfully recruiting and activating key downstream signaling molecules such as PI3K, Vav, and PLC-γ. Through this mechanism, CD19 enhances BCR-mediated signal transduction, significantly lowers the activation threshold for B cells, and makes immune responses more sensitive and efficient.
CD19是免疫球蛋白超家族的I型跨膜糖蛋白，为B细胞特异性标志物，在B细胞发育全程持续表达，终末分化为浆细胞时消失。由于其本身不具备激酶活性，因此需要与CD21、CD81等蛋白形成B细胞共受体复合物来发挥作用，作为B细胞受体（BCR）的共受体，当BCR识别抗原时，它可协同BCR将抗原蛋白拉近并加强结合程度，然后迅速激活CD19胞内段相连的Lyn等激酶，同时强力招募并激活下游关键的PI3K、Vav、PLC-γ等信号分子，通过该机制可增强 BCR介导的信号传导，显著降低了B细胞活化阈值，使免疫应答变得更加灵敏高效。
c-MET is a receptor tyrosine kinase encoded by the MET proto-oncogene. It consists of an extracellular ligand-binding domain, a transmembrane region, and an intracellular tyrosine kinase domain, and is primarily located on the cell surface. Its sole ligand is Hepatocyte Growth Factor (HGF). Under normal physiological conditions, binding with...
c-MET is a receptor tyrosine kinase encoded by the MET proto-oncogene. It consists of an extracellular ligand-binding domain, a transmembrane region, and an intracellular tyrosine kinase domain, and is primarily located on the cell surface. Its sole ligand is Hepatocyte Growth Factor (HGF). Under normal physiological conditions, binding with its ligand HGF activates downstream signaling pathways, regulating cell proliferation, migration, differentiation, survival, and tissue repair. This is crucial for embryonic development and maintaining tissue homeostasis in adults. However, when the MET gene undergoes mutation, amplification, overexpression, or exon 14 skipping, the c-MET signaling pathway becomes abnormally and constitutively activated. This drives tumor growth, invasion, metastasis, and angiogenesis, and is also a key mechanism of resistance to EGFR-targeted therapies.
c-MET（细胞间质上皮转换因子/肝细胞生长因子受体/HGFR）是一种由MET原癌基因编码的受体酪氨酸激酶，由胞外配体结合区、跨膜区和胞内酪氨酸激酶结构域组成，主要存在于细胞表面，唯一配体为肝细胞生长因子（HGF）。其功能正常时，与配体HGF结合后，可激活下游信号通路，调控细胞的增殖、迁移、分化、存活及组织修复，对胚胎发育和成人组织稳态至关重要，但当MET基因发生突变、扩增、过表达或发生14号外显子跳跃时，会导致c-MET信号通路被异常、持续激活，从而驱动肿瘤的生长、侵袭、转移和血管生成，也是导致EGFR靶向药耐药的主要机制之一。
TSLP (Thymic Stromal Lymphopoietin) is a pleiotropic cytokine primarily secreted by epithelial cells, fibroblasts, mast cells, etc. It mainly acts on various cells such as dendritic cells, T cells, and B cells, promoting their activation, differentiation, and proliferation, and inducing them to secrete Th2 cytokines. It activates signaling...
TSLP (Thymic Stromal Lymphopoietin) is a pleiotropic cytokine primarily secreted by epithelial cells, fibroblasts, mast cells, etc. It mainly acts on various cells such as dendritic cells, T cells, and B cells, promoting their activation, differentiation, and proliferation, and inducing them to secrete Th2 cytokines. It activates signaling pathways like JAK-STAT, thereby initiating Th2-type immune responses and playing a crucial role in immune regulation, inflammatory responses, and disease development.