A cytotoxic CD40/p55 tumor necrosis factor receptor hybrid detects CD40 ligand on herpesvirus saimiri-transformed T cells.
The B cell activation molecule CD40 and the p55 tumor necrosis factor receptor (p55TNFR) belong to the same family of structurally conserved proteins. We constructed a chimeric receptor consisting of the CD40 extracellular and transmembrane domains and the p55TNFR intracellular domain. This receptor hybrid retained the biological activity and the ligand specificity of the respective wild-type receptor domains. Thus it exerted a marked cytotoxic effect in three different transfected cell lines after activation not only with anti-CD40 antibody but also with CD40 ligand (CD40L) in soluble and membrane-bound forms. Using hybrid-transfected baby hamster kidney cells we demonstrated that herpesvirus saimiri-transformed human CD4+ T lymphocytes constitutively express bioactive CD40 ligand on their surface. The hybrid receptor-based assay was highly specific for CD40 activating reagents and more sensitive than an assay measuring CD40-mediated B cell rescue from apoptosis. Hence CD40/p55TNFR transfectants may be useful for dissecting CD40L-mediated events in T-B cell interactions, and also to detect a defective CD40L molecule in putative hyper-IgM syndrome patients.
Hess
S
S
Institute for Immunology, University of Munich, Germany.
Kurrle
R
R
Lauffer
L
L
Riethmüller
G
G
Engelmann
H
H
D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis / Q000276:immunology*; D001483:Base Sequence; D019013:CD40 Antigens; D023201:CD40 Ligand; D002461:Cell Line, Transformed; D006224:Cricetinae; D003601:Cytotoxicity Tests, Immunologic; D006567:Herpesvirus 2, Saimiriine; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D018123:Receptors, Interleukin / Q000096:biosynthesis / Q000276:immunology; D019948:Receptors, Interleukin-4; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D019013:CD40 Antigens; D008562:Membrane Glycoproteins; D018123:Receptors, Interleukin; D019948:Receptors, Interleukin-4; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; D023201:CD40 Ligand