title: Activation of T cells via tumor antigen specific chimeric receptors: the role of the intracellular signaling domain.
abstract: T cells engineered to express hybrid receptors with antibody defined specificity can successfully be targeted to tumor cells. In order to select intracellular domains of chimeric receptors capable of efficiently activate T cells in vitro and in vivo, we compared the function of receptors, which share the same extracellular antigen-binding part, joined to different intra-cellular signal transduction units. The antigen binding domain of the receptors was a single-chain fragment of a monoclonal antibody, which recognize a High Molecular Weight Melanoma-Associated Antigen with high affinity. The intracellular tails were derived from the T-cell receptor zeta chain (TCR-zeta), from the B-cell receptor Ig-alpha molecule and from a mutated Ig-alpha molecule able of stronger signal transduction. We compared the activity of the different chimeric receptors at a single-cell level by using a T-cell line that expressed an activation-dependent EGFP-reporter gene. Upon cross-linking with immobilized antibodies, all receptors were able to induce EGFP expression in the majority of the T cells. In contrast, EGFP expression was induced by contact to melanoma cells in vitro only in T cells that expressed the chimeric receptor that contained the TCR-zeta intracellular tail. In these T cells, the co-expression of chimeric receptors that contain a mutated Ig-alpha tail lowers the threshold of T-cell activation and facilitates tumor recognition in vitro and in vivo. Given their specificity and efficiency, T cells grafted with these type of receptors may represent potential candidates for cancer passive immunotherapy.
authors.affiliation: Department of Molecular Immunology, Biology III, University of Freiburg and Max-Planck-Institute for Immunobiology, Germany.
authors.forename: Florian O
authors.initials: FO
authors.lastname: Losch
authors.forename: Ralph
authors.initials: R
authors.lastname: Müller
authors.forename: Bettina
authors.initials: B
authors.lastname: Mutschler
authors.forename: Dario
authors.initials: D
authors.lastname: Neri
authors.forename: Pier Giorgio
authors.initials: PG
authors.lastname: Natali
authors.forename: Michael
authors.initials: M
authors.lastname: Reth
authors.forename: Rita
authors.initials: R
authors.lastname: Carsetti
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000276:immunology; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism; D001202:Ascitic Fluid / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D049452:Green Fluorescent Proteins; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000276:immunology; D066298:In Vitro Techniques; D008164:Luminescent Proteins / Q000378:metabolism; D008213:Lymphocyte Activation; D008545:Melanoma / Q000276:immunology* / Q000628:therapy; D008546:Melanoma, Experimental / Q000276:immunology / Q000628:therapy*; D051379:Mice; D016513:Mice, SCID; D018613:Microscopy, Confocal; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D015398:Signal Transduction / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D017252:CD3 Complex; D049452:Green Fluorescent Proteins; D007135:Immunoglobulin Variable Region; D008164:Luminescent Proteins; D011947:Receptors, Antigen, B-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011993:Recombinant Fusion Proteins; D000099216:Chondroitin Sulfate Proteoglycan 4