Anti-Hu CD40, 5C3, AD, 100tests

A fluorochrome-conjugated monoclonal antibody from STEMCELL Technologies, clone 5C3, targeting human CD40, a B-cell activation marker. The reagent is supplied ready for use and is optimized for flow cytometry, immunophenotyping, and functional applications, and the 5C3 clone has been employed for the activation of B cells and the induction of B cell proliferation in in vitro functional assays.

CD40 is a 45–50 kDa type I transmembrane glycoprotein and a member of the TNFR superfamily. It plays an important role in B cell development and is involved in the process of B cell selection in germinal centres. CD40 facilitates T cell–B cell interactions for co-stimulation and immune regulation through engagement with CD154 (gp39), the CD40 ligand expressed on T cells. In the presence of IL-4, or other stimuli, CD40 promotes B cell proliferation, induces immunoglobulin isotype class-switching, and rescues B cells from surface Ig-induced apoptosis. The antibody is of the IgG1, kappa isotype.

CD40 is expressed on the surface of B cells, follicular dendritic cells, macrophages, fibroblasts, keratinocytes, endothelial cells, basal epithelial cells, CD34+ hematopoietic progenitor cells, and primary carcinomas, and is expressed at low levels, or not at all, on plasma cells. The clone is reported to react with baboon, chimpanzee, cynomolgus monkey, human, rhesus macaque, and squirrel monkey. For storage, keep refrigerated at 2–8 °C, protect from light, and avoid repeated freeze–thaw cycles. For research use only; not for diagnostic or therapeutic use.