Reactome | Co-stimulation by CD28

Co-stimulation by CD28

Stable Identifier

R-HSA-389356

Type

Pathway

Species

Homo sapiens

Synonyms

CD28 co-stimulation

ReviewStatus

5/5

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General

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CD28 signaling plays a critical role in shaping immune responses by ensuring effective T-cell activation and enhancing T-cell survival and proliferation. When CD28 engages its ligands, B7-1 (CD80) and B7-2 (CD86), on antigen-presenting cells, it provides an essential secondary signal that complements T-cell receptor (TCR) activation. This costimulatory signal leads to the production of interleukin-2 (IL-2), which supports the clonal expansion of T cells, promoting both their proliferation and survival by initiating anti-apoptotic pathways (Ribot et al. 2012, Alegre et al. 2001).

The cytoplasmic tail of CD28, upon ligand binding, undergoes phosphorylation by Src family kinases like LCK and FYN, triggering downstream signaling pathways involving PI3K, VAV-1, Tec family kinases, AKT, and other adaptor proteins (Sharpe & Freeman 2002; Chen & Flies 2013).

Literature References

PubMed ID	Title	Journal	Year
8609386	Interactions of CD80 and CD86 with CD28 and CTLA4 Crowe, JS, Vinogradov, DV, Linge, C, Ellis, JH, Burden, MN	J Immunol	1996
12165654	CD28 costimulation: a source of Vav-1 for TCR signaling with the help of SLP-76? Acuto, O, Michel, F	Sci STKE	2002
8649453	Differential recognition by CD28 of its cognate counter receptors CD80 (B7.1) and B70 (B7.2): analysis by site directed mutagenesis Couez, D, Olive, D, Hurle, MR, Eichman, C, Sweet, R, Lyn, SD, Ryan, P, Sekaly, RP, Reddy, M, Truneh, A	Mol Immunol	1996