CD40 ligand–CD40 receptor complex (CD40L–CD40)

The CD40 ligand (CD40L)–CD40 receptor complex is a critical costimulatory pathway that mediates the interaction between T cells and antigen-presenting cells, particularly dendritic cells (DCs). CD40 is a member of the tumor necrosis factor receptor superfamily (TNFRSF5) constitutively expressed on DCs, while its ligand, CD40L (CD154), is transiently expressed on activated CD4+ T cells (UniProt, 2024). Binding of CD40L to CD40 on DCs triggers 'licensing,' a process that upregulates MHC and costimulatory molecules (CD80/CD86) and induces IL-12 production, which is essential for the priming of cytotoxic T lymphocytes (Grewal & Flavell, 1998). In autoimmune diseases like systemic lupus erythematosus and in organ transplantation, blocking this interaction is a therapeutic goal to prevent aberrant immune activation (Karnell et al., 2019). Conversely, in oncology, CD40 agonists are utilized to stimulate DCs to enhance anti-tumor immunity (Vonderheide, 2020). Historically, targeting CD40L was complicated by thromboembolic events due to CD40L expression on platelets, leading to the development of next-generation, Fc-modified antibodies and CD40-specific antagonists to improve safety (Shock et al., 2015).

Other names

CD40-CD154 interactionCD40-CD40L axisTNFSF5-TNFRSF5 interactionCD40-CD40L costimulatory pathway

CD40 receptor agonism; CD40 receptor antagonism; CD40 ligand inhibition