CD28主要作为“第二信号” （与靶细胞表面的B7-1/ B7-2结合） 降低有效活化T细胞所需的阈值，强化激活T细胞的“第一信号” （T细胞受体（TCR）- CD3复合物对靶细胞的MHC-多肽识别和结合），使T细胞进一步发育，增殖为具有免疫功能的细胞。 同时 CD28和共抑制受体CTLA-4与其共享的配体B7-1和B7-2构成了特征最明确的调节T细胞途径，是其他共刺激和共抑制途径的范例。 基于CD28共刺激对于 T细胞活化 的重要性，因此 通过激活或阻断CD28/B7-1（CD80）/ B7 …

CD80及CD86与T细胞表面的受体CD28蛋白结合，给与初始T细胞活化的信号，产生刺激效应：促使T细胞活化、增殖与分化；诱导T细胞表面IL-2受体上调，增加IL-2 mRNA的转录，促进细胞因子的分泌；CD28调节Fas/FasL介导的细胞凋亡途径等。

2001年11月19日 · CD28 is a homodimeric type 1 transmembrane protein that is a member of the immunoglobulin (Ig) superfamily and has a single Ig-like domain. CD28 interacts with CD80 (also known as B7-1) and...

1997年2月3日 · The structurally related T cell surface molecules CD28 and CTLA-4 interact with cell surface ligands CD80 (B7-1) and CD86 (B7-2) on antigen-presenting cells (APC) and modulate T cell antigen recognition. Preliminary reports have suggested that CD80 binds CTLA-4 and CD28 with affinities (Kd values ap …

2022年4月4日 · To address this, here we utilize directed evolution to engineer a CD80 IgV domain with increased PD-L1 affinity and fuse this to an immunoglobulin Fc domain, creating a therapeutic (ALPN-202,...

This article reviews the CD28/CTLA4 and CD80/CD86 families, and outlines the functional outcomes and biochemical signaling pathways recruited after CD28 ligation. T cell stimulation in the absence of a second, costimulatory signal can lead to anergy or the induction of cell death.

2018年7月31日 · The simulations predict a mechanism of CD28 movement, according to which CD28-CD80 complexes passively follow TCR-pMHC microclusters. However, the characteristic CD28-CD80 localization in a ring pattern around the cSMAC only emerges with a particular CD28-actin coupling strength that induces a centripetal motion.

2023年3月6日 · CD28是TCR激活后T细胞信号传导关键介质，CD28与其配体CD80/CD86结合后，激活并驱动T细胞功能、增殖和存活的下游信号。 而除了作为T细胞活化的第二信号外，近年来研究还发现CD28通路的激活针对PD-1/-L1的免疫治疗也有重大意义。

2014年12月15日 · In this study, we show that Tregs form stable conjugates with DCs before, but not after, they decrease surface expression of the costimulatory molecule CD80 on the DCs. We use supported planar bilayers to show that Tregs dramatically slow down but maintain a highly polarized and motile phenotype after recognizing Ag in the absence of costimulation.

The ligands or counterreceptors for these two proteins are the B7 family members, CD80 (B7-1) and CD86 (B7-2). This article reviews the CD28/CTLA4 and CD80/CD86 families, and outlines the functional outcomes and biochemical signaling pathways recruited after CD28 ligation.