关键词: 天然, 骨髓移植, 免疫耐受

Abstract: Objective To study the relationship of donor-derived NK cells as pretreatment condition and immune tolerance after MHC haplotype-mismatched BMT in mice. Methods The murine model of MHC haplotype-mismatched BMT was established by using (BALB/c^H-2d×C57BL／6^H-2b) CB6F₁^H-2d/b mouse as the recipient, and C57BL／6^H-2b mouse as the donor. Seventy recipient mice were divided into seven groups after irradiation (TBI 60Co 9.0　Gy). Control groups: simple-irradiation group, MHC haplotype-mismatched GVHD-control group, MHC haplotype-mismatched BMT group, syngeneic BMT group. Experimental groups: the mice were distributed into three groups of different doses of NK cells which were 1×10⁶/one，5×10⁵/one，2×10⁵/one. CB6F1^H-2d/b mice were conditioned with 9.0 Gy, and the donor-derived NK cells were injected into CB6F₁^H-2d/b mice, after a interval of four hours followed by infusion of C57BL／6^H-2b mice bone marrow cells. The effect was assessed by hemotopoietic reconstruction, survival time, body weight, histopathology in the recipients.　Results ①Life span: in the case of control group, survival time was (5.15±0.66) days for the simple-irradiation group, survival time was (15.80±1.93)days for MHC haplotype-mismatched GVHD-control group, beyond 30 days for other groups. ②Pathological results: GVHD pathological manifestations were found in MHC haplotype-mismatched GVHD-control group. The effects in other cases assessed by histopathology indicated no GVHD. Conclusion The results have shown that donor-derived NK cells as pretreatment condition can induce immune tolerance after MHC haplotype-mismatched BMT in mice.

Key words: atural, one marrow transplantation, mmune tolerance