[The action of donor-derived NK cell in leukemic mice MHC haplotype-mismatched bone marrow transplantation].

OBJECTIVE

To study the role of donor-derived NK cells in haploidentical bone marrow transplantation (BMT) in leukemic mice.

METHODS

CB6F1(H-2b/d) mice model of EL9611 (H-2d) erythroleukemia was established by injection of EL9611 (H-2d) cells via tail vein. CB6F1(H-2b/d) mice were used as recipient, and C57BL/6(H-2b) mice as donor. Five days later, 70 CB6F1(H-2b/d) mice were randomly divided into 7 groups (10 mice per group) as follows: group 1: without treatment; group 2: simple-irradiated group; group 3: treated with cytarabine (Ara-C) at 50 mg/kg x6 d; group 4: simple BMT; group 5: haploidentical BMT with graft-versus-host disease (GVHD) that injected with bone marrow cells and spleen cells of C57BL/6(H-2b) mice 4 hours after irradiation; group 6: after irradiated with 9 Gy, mice were injected with C57BL/6(H-2b) NK cells (1 x 10(6)) and 4 hours later with BM cells, group 7: after irradiation of 9 Gy, mice were injected with C57BL/6(H-2b) NK cells (1 x 10(6)) and 4 hours later with BM cells and spleen cells. The blood routine test, survival time, body weight, and histopathology in the recipients were observed and compared among these group.

RESULTS

The survival time was (10.1 +/- 0.9), (9.8 +/- 0.9), (22.7 +/- 3.2) and (20.1 +/- 1.7) days in groups 1, 2, 3, and 5 respectively; was (30.1 +/- 16.0) days in group 4, out of which 2 mice survived for more than 30 days. The survival time was (39.1 +/- 18.1) and (49.3 +/- 17.2) days in groups 6 and 7 respectively, out of which 4 mice in group 6 and 7 mice in group 7 survived for more than 30 days. The survival time in group 6 was much longer than that in group 1, 2, 3 and 5 (P < 0.01). The survival time in group 7 was much longer than that in other groups (P < 0.05). The liver and spleen enlargement, organ destruction and infiltration with leukemic cells were observed in mice died from leukemia. The chimerism of Y chromosome appeared (80%-90%) in long-term survival mice in groups 6 and 7.

CONCLUSION

Donor-derived NK cells have the antileukemia ability and reduce GVHD in haploidentical BMT in erythroleukemia mice (EL9611, H-2d).