title: Detection of intestinal inflammation by MicroPET imaging using a (64)Cu-labeled anti-beta(7) integrin antibody.
abstract: BACKGROUND
  The primary function of integrin beta(7) is the recruitment and retention of lymphocytes to the inflamed gut. The aim of this study was to investigate the possibility of imaging colitis radioimmunodetection by targeting the beta(7) integrin with a radiolabeled antibody.
  
  
  METHODS
  FIB504.64, a monoclonal antibody that binds to beta(7) integrin, was conjugated with a bifunctional chelator and labeled with (64)Cu. The antibody (50 microg, 7 MBq) was injected into C57BL/6 mice with experimentally induced colitis (n = 6). MicroPET images were collected at 1, 24, and 48 hours postinjection and the biodistribution was measured at 48 hours by tissue assay. Data were also obtained for a (64)Cu-labeled nonspecific isotype-matched antibody in mice with colitis and (64)Cu-labeled FIB504.64 in healthy mice (n = 5-6).
  
  
  RESULTS
  The microPET images showed higher uptake of (64)Cu-labeled FIB504.64 in the gut of mice with colitis than for either of the controls. This observation was confirmed by the 48-hour ex vivo biodistribution data: the percentage of injected dose per gram of tissue (%ID/g +/- SD) (large intestine) colitis mice with (64)Cu-labeled FIB504.64, 6.49 +/- 2.25; control mice with (64)Cu-labeled FIB504.64, 3.64 +/- 1.12; colitis mice, (64)Cu-labeled nonspecific antibody 3.97 +/- 0.48%ID/g (P < 0.05 between groups).
  
  
  CONCLUSIONS
  The selective uptake of (64)Cu-labeled FIB504.64 antibody in the gut of animals with colitis suggests that integrin beta(7) may be a promising target for radioimmunodetection of this disease, which would aid diagnosis, assessment, and therapy guidance of this disease.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Children's Hospital, Boston, Massachusetts 02115, USA. jason.dearling@childrens.harvard.edu
authors.forename: Jason L J
authors.initials: JL
authors.lastname: Dearling
authors.forename: Eun Jeong
authors.initials: EJ
authors.lastname: Park
authors.forename: Patricia
authors.initials: P
authors.lastname: Dunning
authors.forename: Amanda
authors.initials: A
authors.lastname: Baker
authors.forename: Frederic
authors.initials: F
authors.lastname: Fahey
authors.forename: S Ted
authors.initials: ST
authors.lastname: Treves
authors.forename: Sulpicio G
authors.initials: SG
authors.lastname: Soriano
authors.forename: Motomu
authors.initials: M
authors.lastname: Shimaoka
authors.forename: Alan B
authors.initials: AB
authors.lastname: Packard
authors.forename: Dan
authors.initials: D
authors.lastname: Peer
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D003092:Colitis / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000276:immunology; D003301:Copper Radioisotopes; D016264:Dextran Sulfate / Q000633:toxicity; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000276:immunology; D039641:Integrin beta Chains / Q000276:immunology*; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging*; D051379:Mice; D008810:Mice, Inbred C57BL; D049268:Positron-Emission Tomography; D016719:Radioimmunodetection; D019275:Radiopharmaceuticals; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D003301:Copper Radioisotopes; D039641:Integrin beta Chains; D019275:Radiopharmaceuticals; C091368:integrin beta7; D016264:Dextran Sulfate