title: TBI with lung dose reduction does not improve hematopoietic cell homing to BM during allogeneic transplantation.
abstract: To determine the effects of TBI dose, fractionation and lung shielding on hematopoietic stem cell homing to the BM, BM cells were extracted from tibiae and femurs of B6-green fluorescent protein (GFP) mice and transplanted into B6 mice. Recipient mice had either: (i) no radiation, (ii) single-dose TBI at 13.6 Gy, (iii) single-dose TBI at 13.6 Gy with reduced lung exposure to 0.4 Gy by shielding, (iv) split-dose TBI at 12 Gy to twice per day over 4 days or (v) split-dose TBI at 12 Gy to twice per day over 4 days with reduced lung exposure to 0.36 Gy by shielding. The last radiation exposure preceded tail vein injection by 4-6 h. Mice were killed after 18 h. The homing of GFP-positive, lineage-negative cells was not significantly improved in any irradiated group compared with control. The homing of GFP-positive, lineage-negative, Kit-positive cells was significantly worse in all irradiated groups. TBI does not improve the homing of lineage-negative donor BM cells to the recipient marrow. The homing of lineage-negative, Kit-positive donor BM cells was significantly worse following TBI, with or without lung dose reduction.
authors.affiliation: Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA anurag.singh@roswellpark.org
authors.forename: A K
authors.initials: AK
authors.lastname: Singh
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Calado
authors.forename: A
authors.initials: A
authors.lastname: Sowers
authors.forename: J B
authors.initials: JB
authors.lastname: Mitchell
authors.forename: A J
authors.initials: AJ
authors.lastname: Barrett
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D008168:Lung / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D014916:Whole-Body Irradiation