Soluble CD40L activates soluble and cell-surface integrin αvβ3, α5β1, and α4β1 by binding to the allosteric ligand-binding site (site 2).

ABSTRACT: CD40L is a member of the TNF superfamily that participates in immune cell activation. It binds to and signals through several integrins, including αvβ3 and α5β1, which bind to the trimeric interface of CD40L. We previously showed that several integrin ligands can bind to the allosteric site (site 2), which is distinct from the classical ligand-binding site (site 1), raising the question of if CD40L activates integrins. In our explorations of this question, we determined that integrin α4β1, which is prevalently expressed on the same CD4+ T cells as CD40L, is another receptor for CD40L. Soluble (s)CD40L activated soluble integrins αvβ3, α5β1, and α4β1 in cell-free conditions, indicating that this activation does not require inside-out signaling. Moreover, sCD40L activated cell-surface integr

SUBMITTER: Takada YK 

PROVIDER: S-EPMC7960543 | biostudies-literature | 2021 Jan-Jun

REPOSITORIES: biostudies-literature