Feasibility and limits of bone marrow mononuclear cell expansion following irradiation

Abstract

Purpose: To define the ability of bone marrow mononuclear cells (BMMNC) to expand after irradiation and to determine the amount of apoptosis in irradiated expanded cells.

Materials and methods: Non‐human primate BMMNC were irradiated in vitro at doses ranging from 0 to 4 Gy and were cultured during 1 week in the presence of interleukin 3, interleukin 6, stem cell factor, thrombopoietin and fms‐like tyrosine kinase‐3 ligand. The expansion yield of BMMNC, colony‐forming cells and CD34⁺ cells were compared with non‐irradiated control cultures. Apoptosis in expanded cells was also defined by annexin V/propidium iodine staining.

Results: Irradiation of BMMNC up to 1 Gy did not modify the ability of haematopoietic cells to expand. At higher doses, expansion of haematopoietic cells is reduced as compared with non‐irradiated cultures but it remains significant. This reduction in expansion of BMMNC was related to radiation‐induced apoptosis.

Conclusion: The results suggest that it is possible to expand haematopoietic cells after irradiation doses at least up to 2 Gy. This suggests a possible use of cell therapy for the treatment of radiation accident victims.