title: Human native soluble CD40L is a biologically active trimer, processed inside microsomes.
abstract: CD40 ligand (CD40L) is a glycoprotein expressed on the surface of activated helper T cells, basophils, mast cells, and eosinophils. Binding of CD40L to its receptor CD40 on the B cell surface induces B cell proliferation, adhesion, and immunoglobulin class switching. We have identified soluble cleavage products of human CD40L in the supernatant of a stimulated human T cell clone. Subcellular fractionation experiments have shown that the transmembrane CD40L is processed inside the microsomes and that its cleavage is stimulation-dependent. The native human soluble CD40L is trimeric and, when used in conjunction with interleukin-4, induces B cell proliferation.
authors.affiliation: Glaxo Institute for Molecular Biology, Geneva, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Pietravalle
authors.forename: S
authors.initials: S
authors.lastname: Lecoanet-Henchoz
authors.forename: H
authors.initials: H
authors.lastname: Blasey
authors.forename: J P
authors.initials: JP
authors.lastname: Aubry
authors.forename: G
authors.initials: G
authors.lastname: Elson
authors.forename: M D
authors.initials: MD
authors.lastname: Edgerton
authors.forename: J Y
authors.initials: JY
authors.lastname: Bonnefoy
authors.forename: J F
authors.initials: JF
authors.lastname: Gauchat
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D019013:CD40 Antigens / Q000378:metabolism*; D023201:CD40 Ligand; D002460:Cell Line; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008861:Microsomes / Q000276:immunology / Q000378:metabolism; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D019013:CD40 Antigens; D008024:Ligands; D008562:Membrane Glycoproteins; D023201:CD40 Ligand