CD28是以同二聚体形式表达在T细胞膜表面的44kD蛋白，是T细胞活化的主要共刺激分子受体家族，其受体为B7-1 (CD80)和B7-2（CD86），在激活的DC细胞和其他APC上表达；CD28家族的另一个共刺激分子是ICOS（inducible costimulatory，CD278），ICOS在T细胞依赖的抗体反应中起到重要的作用，尤其是在生发中心形成的过程中；是滤泡help T细胞发育和激活的必须分子； CD28家族还包括抑制性的共刺激分子， CTLA-4 和 PD-1。 CTLA4:B7，其共刺激信号可以抑 …

2003年12月1日 · CD28 potently enhances T-cell receptor (TCR)-induced proliferation and differentiation of naive T cells, especially at low TCR occupancy, making it responsible for the signal two predicted by...

Ligation of the CD28 receptor on T cells provides a critical second signal alongside T cell receptor (TCR) ligation for naive T cell activation. Here we discuss the expression, structure, and biochemistry of CD28 and its ligands.

2022年8月31日 · CD28增强TCR驱动的酪氨酸磷酸化，并与磷脂酰肌醇3激酶（PI3K）和Grb2募集一起作用，分别触发Akt-mTor和Ras-MAPK途径。 淋巴细胞功能最具特征的负性调节受体是PD-1和CTLA-4，它们代表了T细胞抑制性受体的范例。

2015年1月1日 · In this paper, using primary T-cells from various knock-out (Cd28 −/−, adap −/−) and knock-in (i.e. Cd28 Y-170F) mice in conjunction with transfected Jurkat T-cells, we show that the TCR and CD28 use distinct pathways for the activation of the NF-κB pathway in T-cells. Our findings provide further evidence that the CD28 and TCR ...

Using total internal reflection fluorescence (TIRF) microscopy and a supported lipid bilayer functionalized with an ovalbumin peptide–MHC class I complex (pMHC; TCR ligand) and B7.1 (CD28 ligand), we found that PD-1 strongly colocalized with the costimulatory receptor CD28 in plasma membrane microclusters (Fig. 3 and movie S1).

2000年12月26日 · Here we show that, by enhancing T cell/APC close contacts, CD28 facilitates TCR signal transduction. Moreover, the signal supplied by CD28 does not lead to increased Zap-70 and Lat phosphorylation, but amplifies PLCγ1 activation and Ca 2+ response. We provide evidence that the PTK Itk controls the latter function.

2017年10月24日 · 10月23日，中科院生物化学与细胞生物学研究所 许琛琦 研究组与牛津大学 Omer Dushek 研究组合作在 Nature Structural & Molecular Biology 在线发表了题为“Dynamic regulation of CD28 conformation and signaling by charged lipids and ions”的论文， 该研究揭示了CD28的活性调控机制以及T细胞高 ...

2017年10月25日 · tcr-ca 2+-cd28 的正反馈环路模型. 在静息状态下，带负电荷的酸性磷脂可以屏蔽tcr和cd28的活性位点；生理条件下，抗原的数量非常微量，抗原对tcr的初始激活可以诱发ca 2+ 内流；内流的ca 2+ 通过静电竞争解除tcr和cd28的活性位点，促进它们的信号转导；tcr和cd28的信号转导都可以进一步引起ca 2+ 内流。

CD28, the most valuable costimulatory receptor, forms TCR-CD28 microclusters in cooperation with TCRs, associates with protein kinase C theta, and effectively induces initial T-cell activation. After mature IS formation, CD28 microclusters accumulate at a particular subregion of the IS, where they continuously assemble with the kinases and not ...