title: 64Cu antibody-targeting of the T-cell receptor and subsequent internalization enables in vivo tracking of lymphocytes by PET.
abstract: T cells are key players in inflammation, autoimmune diseases, and immunotherapy. Thus, holistic and noninvasive in vivo characterizations of the temporal distribution and homing dynamics of lymphocytes in mammals are of special interest. Herein, we show that PET-based T-cell labeling facilitates quantitative, highly sensitive, and holistic monitoring of T-cell homing patterns in vivo. We developed a new T-cell receptor (TCR)-specific labeling approach for the intracellular labeling of mouse T cells. We found that continuous TCR plasma membrane turnover and the endocytosis of the specific (64)Cu-monoclonal antibody (mAb)-TCR complex enables a stable labeling of T cells. The TCR-mAb complex was internalized within 24 h, whereas antigen recognition was not impaired. Harmful effects of the label on the viability, DNA-damage and apoptosis-necrosis induction, could be minimized while yielding a high contrast in in vivo PET images. We were able to follow and quantify the specific homing of systemically applied (64)Cu-labeled chicken ovalbumin (cOVA)-TCR transgenic T cells into the pulmonary and perithymic lymph nodes (LNs) of mice with cOVA-induced airway delayed-type hypersensitivity reaction (DTHR) but not into pulmonary and perithymic LNs of naïve control mice or mice diseased from turkey or pheasant OVA-induced DTHR. Our protocol provides consequent advancements in the detection of small accumulations of immune cells in single LNs and specific homing to the sites of inflammation by PET using the internalization of TCR-specific mAbs as a specific label of T cells. Thus, our labeling approach is applicable to other cells with constant membrane receptor turnover.
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Griessinger
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Andreas
authors.initials: A
authors.lastname: Maurer
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Christian
authors.initials: C
authors.lastname: Kesenheimer
authors.affiliation: Department of Diagnostic and Interventional Radiology.
authors.forename: Rainer
authors.initials: R
authors.lastname: Kehlbach
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Gerald
authors.initials: G
authors.lastname: Reischl
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Walter
authors.initials: W
authors.lastname: Ehrlichmann
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bukala
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Maren
authors.initials: M
authors.lastname: Harant
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center.
authors.forename: Funda
authors.initials: F
authors.lastname: Cay
authors.affiliation: Department of Dermatology.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brück
authors.affiliation: Department of Dermatology.
authors.forename: Renate
authors.initials: R
authors.lastname: Nordin
authors.affiliation: Department for Pathology, and.
authors.forename: Ursula
authors.initials: U
authors.lastname: Kohlhofer
authors.affiliation: Department of Immunology, Eberhard Karls University, 72076 Tübingen, Germany; and German Cancer Consortium, German Cancer Research Center Partner Site Tübingen, 72076 Tübingen, Germany.
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Rammensee
authors.affiliation: Department for Pathology, and.
authors.forename: Leticia
authors.initials: L
authors.lastname: Quintanilla-Martinez
authors.affiliation: Department of Dermatology.
authors.forename: Martin
authors.initials: M
authors.lastname: Schaller
authors.affiliation: Department of Dermatology.
authors.forename: Martin
authors.initials: M
authors.lastname: Röcken
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Bernd.Pichler@med.uni-tuebingen.de.
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Pichler
authors.affiliation: Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Department of Dermatology.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kneilling
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D017209:Apoptosis / Q000276:immunology; D003301:Copper Radioisotopes; D004249:DNA Damage / Q000276:immunology; D051379:Mice; D049268:Positron-Emission Tomography / Q000379:methods*; D011849:Radioactive Tracers; D011859:Radiography; D011946:Receptors, Antigen / Q000037:antagonists & inhibitors* / Q000276:immunology; D013601:T-Lymphocytes / Q000000981:diagnostic imaging* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D003301:Copper Radioisotopes; D011849:Radioactive Tracers; D011946:Receptors, Antigen
keywords: PET imaging; airway DTHR; antibody-based cell labeling; in vivo cell tracking; mouse T cells