This antibody targets CD40 Ligand (CD40L), also known as CD154 or TRAP, a type II transmembrane protein belonging to the TNF superfamily. CD40L is transiently expressed primarily on activated CD4+ T cells and interacts with CD40, which is expressed on antigen-presenting cells (APCs) like B cells, macrophages, and dendritic cells. This interaction is crucial for T cell-dependent B cell activation, immunoglobulin class switching, germinal center formation, and licensing dendritic cells for effective cytotoxic T cell priming.

Validated for immunofluorescence, immunohistochemistry, and flow cytometry applications, this antibody enables the study of T cell-B cell collaboration, APC activation, humoral immunity development, germinal center dynamics, and is relevant for understanding immunodeficiencies (like Hyper-IgM syndrome) and autoimmune diseases.