Whole-body Irradiation and Long-term Modification of Bone Marrow-derived Cell Populations by Low- and High-LET Radiation

Abstract

Background: The major aim of this study was to quantify long-term changes in bone marrow-derived cell populations after exposure to radiations of differing quality. Materials and Methods: Mice were whole-body irradiated to 2 Gy gamma, proton, carbon or iron radiation, and euthanized ~ 110 days later for immunocyte phenotyping. Results: Splenic lymphocytes and mono/macrophages increased after γ-rays when compared to 0 Gy and one or more of the other groups. There were high T cells (carbon vs. 0 Gy), high B cells (γ-rays vs. 0 Gy), and low natural killer (NK) cells (proton and carbon vs. 0 Gy). All radiations, except γ-rays, increased CD62L⁺ memory T cell counts, whereas CD62L⁺ B cells increased only after γ-rays. Conclusion: There were significant aberrations in many immune parameters nearly 4 months after exposure to various forms of radiation. This suggests radiation exposure can have long-term health consequences.