TNFRSF5/CD40

TNFRSF5/CD40 is a tumor necrosis factor receptor family member expressed by B cells, professional antigen-presenting cells, non-immune cells, and tumors[1]. Mechanistically, CD40-CD40L/CD154 engagement regulates humoral and cellular adaptive immunity, including B-cell proliferation, immunoglobulin isotype switching, and germinal center formation[1][2]. CD40 signaling recruits TRAFs and activates NF-κB, with additional involvement of PI3K/AKT, MAPKs, and JAK3/STAT pathways[3]. In inflammatory disease models, CD40 ligation promotes cytokines, chemokines, matrix metalloproteinases, growth factors, adhesion molecules, and procoagulant responses in vascular and immune-associated cells[4][5]. Compared with related pathway forms, CD40 and CD40L both have membrane and soluble forms, and soluble CD40 may bind CD40L and reduce transmembrane CD40 receptor activation[3][6]. For experimental applications, CD40 agonistic antibodies and CD40L-based strategies require receptor clustering or trimerization, while antagonistic approaches target autoimmune disease, allograft rejection, and inflammatory pathology[3][7].