title: Anti‑migratory effect of rapamycin impairs allograft imaging by 18F‑fluorodeoxyglucose‑labeled splenocytes.
abstract: Tracking lymphocyte migration is an emerging strategy for non‑invasive nuclear imaging of allografts; however, its clinical application remains to be fully demonstrated. In the present study, the feasibility of using rapamycin‑treated 18F‑fluorodeoxyglucose (18F‑FDG)‑labeled splenocytes for the in vivo imaging of allografts was evaluated. C57BL/6 skin was heterotopically transplanted onto non‑obese diabetic/severe combined immunodeficient recipient mice. BALB/c 18F‑FDG‑labeled splenocytes with or without rapamycin pretreatment (designated as FR and FC cells, respectively) were transferred into recipient mice 30 days later. Imaging of radiolabeled cells in the skin grafts was conducted through in vivo dynamic whole‑body phosphor‑autoradiography and histological analysis. Notably, rapamycin impaired the migration of 18F‑FDG‑labeled splenocytes to the graft. At all time points, the radioactivity of allografts (digital light units/mm2) was significantly lower in the group that received FR cells, compared with the group that received FC cells (P<0.01). Furthermore, the peak allograft to native skin ratio was 1.29±0.02 at 60 min for the FR group and 3.29±0.17 at 30 min for the FC group (P<0.001). In addition, the in vivo radioactivity of the allografts was observed to be correlated with the transferred cells, which were observed histologically (r2=0.887; P<0.0001). Although 18F‑FDG‑labeled splenocytes migrated to the allograft, imaging of these cells may not be possible in the presence of rapamycin.
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Hukui
authors.initials: H
authors.lastname: Sun
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Dayan
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Yang
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Biomedical Isotope Research Center, School of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Hou
authors.affiliation: Nuclear Medicine Department, Central Hospital of Zibo, Shandong University, Zibo, Shandong 255036, P.R. China.
authors.forename: Huaiquan
authors.initials: H
authors.lastname: Wang
mesh_terms: D064591:Allografts; D000818:Animals; D001345:Autoradiography / Q000379:methods; D002465:Cell Movement / Q000187:drug effects*; D058948:Cell Tracking / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D008214:Lymphocytes / Q000187:drug effects* / Q000502:physiology*; D051379:Mice; D023421:Models, Animal; D020123:Sirolimus / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology*
chemical_list: D019788:Fluorodeoxyglucose F18; D020123:Sirolimus