Reactome | CTLA-4 binds B7-1/B7-2

CTLA-4 binds B7-1/B7-2

Stable Identifier

R-HSA-388809

Type

Reaction [binding]

Species

Homo sapiens

Compartment

plasma membrane

ReviewStatus

5/5

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CTLA4 binds to B7-1 (CD80) and B7-2 (CD86) with a significantly higher affinity than CD28, allowing it to outcompete CD28 for these ligands and inhibit T cell activation (van der Merwe et al. 1997). This interaction is strengthened by the dimerization of CTLA4, which increases the avidity for B7 molecules (Schwartz et al. 2001). Beyond simply blocking co-stimulation, CTLA4 engagement actively promotes regulatory T cell induction and suppresses effector T cell responses. Additionally, CTLA4's localization to the immunological synapse, regulated by intracellular trafficking, ensures its rapid accumulation upon T cell activation, enhancing its inhibitory effect on immune responses (Egen et al. 2002).

Literature References

PubMed ID	Title	Journal	Year
10799894	Structural analysis of CTLA-4 function in vivo Masteller, EL, Chuang, E, Mullen, AC, Reiner, SL, Thompson, CB	J Immunol	2000
15142525	An autoimmune disease-associated CTLA-4 splice variant lacking the B7 binding domain signals negatively in T cells Vijayakrishnan, L, Slavik, JM, Illés, Z, Greenwald, RJ, Rainbow, D, Greve, B, Peterson, LB, Hafler, DA, Freeman, GJ, Sharpe, AH, Wicker, LS, Kuchroo, VK	Immunity	2004
11976720	Structural mechanisms of costimulation Schwartz, JC, Zhang, X, Nathenson, SG, Almo, SC	Nat Immunol	2002