CD28依赖的Vav1通路
中文名称
通路描述
CD28结合多种细胞内信号蛋白，包括PI3激酶、Grb2、Gads和ITK，这些对于由T细胞受体（TCR）启动并放大的T细胞激活信号至关重要。Grb2特别与Vav1协同工作，以增强NFAT和AP - 1转录因子的激活，这些转录因子是T细胞激活期间基因表达的关键调节因子。与TCR激活相比，CD28共刺激显著延长和增强Vav1磷酸化及其质膜定位的持续时间，表明CD28提供了持续信号，增强了T细胞反应性（Hehner等，2000）。Vav1在将TCR和CD28信号转化为多种下游通路方面起关键作用，对细胞骨架重排有直接影响。在激活后，Vav1触发小GTPase Rac1和Cdc42，进而激活丝裂原活化蛋白激酶（MAPKs）如JNK和p38。在CD28信号背景下，这些通路对于调节细胞因子表达和促进T细胞增殖和生存至关重要（Laura Inés Salazar - Fontana等，2003）。此外，Vav1在CD28共刺激中的作用对于其他细胞过程至关重要，包括钙流、ERK MAPK激活、NF - κB信号和整合素LFA - 1的“内 - 外”激活。这增强了T细胞粘附、聚集和极化，最终有助于更有效的免疫反应。因此，CD28共刺激确保Vav1介导的信号得到充分持续，促进最佳的T细胞激活和功能（Hehner等，2000）。
英文描述
CD28 dependent Vav1 pathway CD28 binds to several intracellular signaling proteins, including PI3 kinase, Grb2, Gads, and ITK, which are crucial for amplifying the T cell activation signal initiated by the T-cell receptor (TCR). Grb2, in particular, works in tandem with Vav1 to enhance the activation of NFAT and AP-1 transcription factors, critical regulators of gene expression during T cell activation. CD28 costimulation significantly extends the duration and intensity of Vav1 phosphorylation and its localization at the plasma membrane compared to TCR activation alone, indicating that CD28 provides a sustained signal that enhances T cell responsiveness (Hehner et al. 2000).
Vav1 plays a pivotal role in transducing signals from both TCR and CD28 to multiple downstream pathways, with a direct impact on cytoskeletal rearrangements. Upon activation, Vav1 triggers the small GTPases Rac1 and Cdc42, which lead to the activation of mitogen-activated protein kinases (MAPKs) like JNK and p38. In the context of CD28 signaling, these pathways are essential for regulating the expression of cytokines and promoting T cell proliferation and survival (Laura Inés Salazar-Fontana et al. 2003).
Additionally, Vav1's involvement in CD28 costimulation is critical for several other cellular processes, including calcium flux, ERK MAPK activation, NF-κB signaling, and the inside-out activation of the integrin LFA-1. This enhances T cell adhesion, clustering, and polarization, ultimately contributing to more effective immune responses. Thus, CD28 costimulation ensures that Vav1-mediated signals are robustly sustained, promoting optimal T cell activation and function (Hehner et al. 2000).
Vav1 plays a pivotal role in transducing signals from both TCR and CD28 to multiple downstream pathways, with a direct impact on cytoskeletal rearrangements. Upon activation, Vav1 triggers the small GTPases Rac1 and Cdc42, which lead to the activation of mitogen-activated protein kinases (MAPKs) like JNK and p38. In the context of CD28 signaling, these pathways are essential for regulating the expression of cytokines and promoting T cell proliferation and survival (Laura Inés Salazar-Fontana et al. 2003).
Additionally, Vav1's involvement in CD28 costimulation is critical for several other cellular processes, including calcium flux, ERK MAPK activation, NF-κB signaling, and the inside-out activation of the integrin LFA-1. This enhances T cell adhesion, clustering, and polarization, ultimately contributing to more effective immune responses. Thus, CD28 costimulation ensures that Vav1-mediated signals are robustly sustained, promoting optimal T cell activation and function (Hehner et al. 2000).
所含基因
11 个基因