title: Preparation and Evaluation of 99mTc-labeled anti-CD11b Antibody Targeting Inflammatory Microenvironment for Colon Cancer Imaging.
abstract: CD11b, an active constituent of innate immune response highly expressed in myeloid-derived suppressor cells (MDSCs), can be used as a marker of inflammatory microenvironment, particularly in tumor tissues. In this research, we aimed to fabricate a (99m)Tc-labeled anti-CD11b antibody as a probe for CD11b(+) myeloid cells in colon cancer imaging with single-photon emission computed tomography (SPECT). In situ murine colon tumor model was established in histidine decarboxylase knockout (Hdc(-/-)) mice by chemicals induction. (99m)Tc-labeled anti-CD11b was obtained with labeling yields of over 30% and radiochemical purity of over 95%. Micro-SPECT/CT scans were performed at 6 h post injection to investigate biodistributions and targeting of the probe. In situ colonic neoplasma as small as 3 mm diameters was clearly identified by imaging; after dissection of the animal, anti-CD11b immunofluorescence staining was performed to identify infiltration of CD11b+ MDSCs in microenvironment of colonic neoplasms. In addition, the images displayed intense signal from bone marrow and spleen, which indicated the origin and migration of CD11b(+) MDSCs in vivo, and these results were further proved by flow cytometry analysis. Therefore, (99m)Tc-labeled anti-CD11b SPECT displayed the potential to facilitate the diagnosis of colon tumor in very early stage via detection of inflammatory microenvironment.
authors.affiliation: Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.|Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
authors.forename: Dengfeng
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital, University of South China, Hengyang, Hunan, 421001, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Zou
authors.affiliation: Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.|Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.|Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiu
authors.affiliation: Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.|Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.|Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Shi
authors.affiliation: Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, FudanUniversity, Shanghai, 200032, China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000276:immunology*; D003106:Colon / Q000000981:diagnostic imaging* / Q000276:immunology* / Q000473:pathology; D003110:Colonic Neoplasms / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000276:immunology*; D018796:Immunoconjugates / Q000737:chemistry / Q000276:immunology; D007249:Inflammation / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000276:immunology; D008807:Mice, Inbred BALB C; D015609:Organotechnetium Compounds / Q000737:chemistry / Q000276:immunology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D039481:CD11b Antigen; D018796:Immunoconjugates; D015609:Organotechnetium Compounds
keywords: SPECT; Tc-99m; anti-CD11b antibody; colon cancer; inflammation; myeloid-derived suppressor cells