title: Changes in the distribution and function of leukocytes after whole-body iron ion irradiation.
abstract: High-energy particle radiation could have a considerable impact on health during space missions. This study evaluated C57BL/6 mice on Day 40 after total-body56Fe26+irradiation at 0, 1, 2 and 3 gray (Gy). Radiation consistently increased thymus mass (one-way ANOVA: P < 0.005); spleen, liver and lung masses were similar among all groups. In the blood, there was no radiation effect on the white blood cell (WBC) count or major leukocyte types. However, the red blood cell count, hemoglobin, hematocrit and the CD8+ T cytotoxic (Tc) cell count and percentage all decreased, while both the CD4:CD8 (Th:Tc) cell ratio and spontaneous blastogenesis increased, in one or more irradiated groups compared with unirradiated controls (P < 0.05 vs 0 Gy). In contrast, splenic WBC, lymphocyte, B cell and T helper (Th) counts, %B cells and the CD4:CD8 ratio were all significantly elevated, while Tc percentages decreased, in one or more of the irradiated groups compared with controls (P < 0.05 vs 0 Gy). Although there were trends for minor, radiation-induced increases in %CD11b+ granulocytes in the spleen, cells double-labeled with adhesion markers (CD11b+CD54+, CD11b+CD62E+) were normal. Splenocyte spontaneous blastogenesis and that induced by mitogens (PHA, ConA, LPS) was equivalent to normal. In bone marrow, the percentage of cells expressing stem cell markers, Sca-1 and CD34/Sca-1, were low in one or more of the irradiated groups (P < 0.05 vs 0 Gy). Collectively, the data indicate that significant immunological abnormalities still exist more than a month after56Fe irradiation and that there are differences dependent upon body compartment.
authors.affiliation: Department of Basic Sciences, Division of Radiation Research, Loma Linda University School of Medicine, Chan Shun Pavilion, 11175 Campus Street, Loma Linda, CA 92354, USA.
authors.forename: Daila S
authors.initials: DS
authors.lastname: Gridley
authors.affiliation: Department of Basic Sciences, Division of Radiation Research, Loma Linda University School of Medicine, Chan Shun Pavilion, 11175 Campus Street, Loma Linda, CA 92354, USA mpecaut@llu.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pecaut
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001772:Blood Cell Count; D001835:Body Weight / Q000187:drug effects / Q000528:radiation effects; D001854:Bone Marrow Cells / Q000187:drug effects / Q000528:radiation effects; D002448:Cell Adhesion / Q000187:drug effects / Q000528:radiation effects; D005260:Female; D007477:Ions; D007501:Iron / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D008213:Lymphocyte Activation / Q000187:drug effects / Q000528:radiation effects; D016131:Lymphocyte Subsets / Q000187:drug effects / Q000528:radiation effects; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects / Q000528:radiation effects; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D014916:Whole-Body Irradiation
chemical_list: D015415:Biomarkers; D007477:Ions; D008934:Mitogens; D007501:Iron
keywords: hematopoiesis; mouse model; particle radiation; spaceflight; total-body irradiation