Effects of sublethal radiation on bone marrow cells: induction of apoptosis and inhibition of antibody formation.
As part of the study to investigate the mechanism of radiation-induced immunosuppression, the survival and functional ability of bone marrow cells was analyzed by exposing C57B1/6 mice whole body to 2.0-Gy gamma-rays. There was a rapid induction of DNA fragmentation in the total bone marrow cells and the kinetics indicated that apoptosis reached a peak by 4 h and then dropped back to normal control levels within 10 h after irradiation. To determine the functional ability of bone marrow cells which survive the radiation treatment, animals were immunized with antigen trinitrophenyl (TNP)-lipopolysaccharide. There was a significant decrease of anti-TNP plaque-forming cells in the bone marrow of irradiated mice compared to control animals. Flow cytometric analysis of bone marrow revealed a significant depletion of both immature (B220+, Ig-) as well as mature (B220+, Ig+) B cells compared to control group. In summary, the present study showed that sublethal whole body irradiation inhibits antibody responses elicited by bone marrow cells. This decreased immune response may have been due to depletion of B lineage subsets as well as generalized apoptosis in the entire bone marrow cells.
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Department of Radiation Medicine, University of Kentucky Medical Center, Lexington 40536, USA. nsgoud@dow.com
D000818:Animals; D000917:Antibody Formation / Q000528:radiation effects; D017209:Apoptosis / Q000528:radiation effects; D001402:B-Lymphocytes / Q000166:cytology / Q000528:radiation effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology / Q000528:radiation effects*; D053938:DNA Fragmentation / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000528:radiation effects; D018655:Lymphocyte Count / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D014916:Whole-Body Irradiation