OBJECTIVETo study the effect of natural killer (NK)-cell on reconstitution of hematopoiesis and immunity in mouse allogeneic bone marrow transplantation (allo-BMT).

METHODSLethally irradiated BALB/c (H-2(d)) mice were transplanted with C57BL/6 (H-2(b)) bone marrow plus peripheral T cells and/or NK cells. Recipients CD34(+) cells and H-2K(b+), CD3(+) and CD19(+) cells were detected by flow cytometry, peripheral white blood cell (WBC) by auto-cytometry, and the survival rates, engraftment, hematopoietic and immune recovery were observed.

RESULTSIn the transplantation with NK cell infusion group, the survival rates, the WBC and CD34(+) cell counts, and the H-2(b+) and CD19(+) cells were significantly higher than that in without NK cell infusion group (P < 0.01). Twenty-eight days after transplantation, the CD3(+) cells in the NK cell infusion group [(33.69 +/- 3.36)%] were lower than that in without [(50.4 +/- 5.06)%] (P < 0.01), and there was no longer difference between these groups 60 days after transplantation (P > 0.05).

CONCLUSIONIn mouse allo-BMT, alloreactive NK cell enhances engraftment, promotes reconstitution of hematopoiesis and immunity and increases survival rates.