[Homing characteristics of graft cells in leukemia mice after allogenic bone marrow transplantation with different conditioning regimens].

The aim of this study was to investigate the homing characteristics of bone marrow cells in leukemia mice after allogenic bone marrow transplantation with different conditioning regimens on the basis of a leukemia mouse model. Allogenic bone marrow transplantation was performed after three different kinds of conditioning regimen, including nonmyeloablative conditioning regimen (5 Gy (60)Co γ ray total body irradiation, A group), radiotherapeutic myeloablative conditioning regimen (9 Gy (60)Co γ ray total body irradiation, B group) and chemotherapeutic myeloablative conditioning regimen (large dose chemotherapy, C group). In the recipient mice, the nucleated cell number in peripheral blood, bone marrow and spleen was counted, the percentage of positive cells capable of connecting with FITC labeled anti-mouse H-2K(b) antibody was detected by flow cytometry and the homing ratio in bone marrow and spleen was calculated at 24, 48, 72, 96 h after bone marrow transplantation. The results showed that donor myeloid cells displayed homing and then mobilization (going out of home) in group A; homing, mobilization, and rehoming in group B and C, and there was a little delay of homing in the spleen in group C. In bone marrow, the homing efficiency of A group was the highest in early period and the lowest [(0.90 ± 0.09)%] in the fourth day with the mobilization of myeloid cells (P < 0.05), and the homing efficiency of B and C groups was lower in the early period and the highest [(2.17 ± 0.26)%, B group] in the fourth day with the rehoming of myeloid cells (P < 0.05). In spleen, the homing efficiency was similar to that in bone marrow and there still was a little delay in C group. It is concluded that the homing ratio is high in the early period and decrease obviously in 72 h after bone marrow of leukemia mice treated with nonmyeloablative conditioning regimen. The homing ratio is low in the early period and increases obviously in 72 h after bone marrow of leukemia mice treated with radio-or chemotherapeutic myeloablative conditioning regimens. The homing ratio does not obviously change between the early period and 72 h after bone marrow of leukemia mice treated with chemotherapeutic myeloablative conditioning regimen, and lies between group A and B.