混合脐血移植后造血及免疫重建特性的研究

目的　探讨混合脐血移植重建造血和免疫功能的特点及规律。方法　分别将两份人HLA半相合、不相合混合脐血或单份脐血输入经亚致死量照射后的严重联合免疫缺陷 (SCID)小鼠。观察三组脐血在SCID小鼠体内植入状况及造血和免疫功能重建特性。结果　单份和混合脐血均可在受鼠体内植入 ,形成供 受混合嵌合体 ,植入率差异无显著性 (P >0 .0 5 ) ,并能重建人类多系造血 ,且易于向NK和B淋巴细胞方向分化。用多聚酶链反应 序列特异性寡核苷酸 (PCR SSO)探针检测人HLA DQB1基因发现 ,混合脐血移植可有 1份或 2份脐血植入 ,其中造血祖细胞含量和体外集落形成能力高者 ,更易于植入 ,且供者间HLA差异小者 ,趋向两份脐血同时植入。结论　混合脐血移植可重建SCID小鼠造血和免疫功能 ,但造血细胞各谱系分化不均衡。

Characteristics of hematopoietic and immunologic reconstitution following co-transplantation of two umbilical cord blood units in SCID mice

Objective To evaluate characteristics of hematopoietic and immunologic reconstitution in mixed cord blood transplantation. Methods Single, 2 human HLA-haploidentical or HLA-mismatched cord blood units were transplanted into sublethally irradiated severe combined immunodeficiency (SCID) mice, respectively. The characteristics of engraftment, multilineage hematopoiesis and immunologic reconstitution among the three guoups were compared. Results Single or 2 cord blood units could engraft SCID mice and reconstitute human hematopoiesis and immunologic functions. No significant differences in engrafting rate were observed. Cord blood cells were apt to differentiate into NK cells and B lymphocytes. One or 2 cord blood units could be implanted in SCID mice simultaneously as shown by HLA-DQB1 gene detection. The cord blood containing more hematopoietic progenitor cells and higher colony forming potentiality was apt to engraft. Moreover, in less HLA disparity group, 2 cord blood units were prone to engraft simultaneously. Conclusions Co-transplantation of two cord blood units can reconstitute hematopoietic and immunologic functions in SCID mice. However, imbalance in multilineage differentiation existed.