天然杀伤细胞在受照射小鼠中的造血调控作用

REGULATING EFFECT OF NATURAL KILLER CELLS ON HEMOPOIESIS IN IRRADIATED MICE

研究了天然杀伤（ＮＫ）细胞对受致死剂量γ线照射的同系小鼠的造血调控作用。ＡＭＳ／５小鼠经９Ｇｙγ线全身照射后立即经尾静脉注射ＮＫ细胞（５×１０５），可明显提高受照小鼠３０ｄ活存率，照后８ｄ小鼠骨髓中ＣＦＵ－ＧＭ数量明显高于对照和脾细胞注射组，照射后３０ｄ，ＮＫ细胞注射组活存小鼠的骨髓有核细胞数和ＣＦＵ－ＧＭ数已恢复到正常的７６％─９６％。病理组织学观察显示，输注ＮＫ细胞可使小鼠骨髓、脾脏的组织损伤程度减轻，造血功能增强，表现为造血灶数增多，造血细胞功能活跃，核分裂相增多，且涉及红系、粒系、巨核细胞系造血。ＮＫ细胞可能通过直接与造血干细胞相互作用或改善造血微环境等促进“内源性”造血功能，从而发挥对造血的正调控作用。提示ＮＫ细胞在小鼠造血功能的平衡维持中起重要作用。

The regulating effect of natural killer (NK) cells on hemopoiesis in 9Gy whole body γ irradiated (WBI) mice was studied.Intravenous injection of 5×105 NK cells immediately after irradiation could delay the death of irradiated mice and raise the 30-day survival rate. On day 8 after irradiation, the CFU-GM count in bone marrow of NK cell-transplanted mice was significantly higher than that of control (irradiated) or splenic cell-transplanted ones. On day 30,the NK cell-transplanted surviving mice had most of their hemopoietic function recovered. The histopathological studies of bone marrow and spleen showed that NK cells could alleviate the injuries caused by irradiation in bone marrow and spleen, activate hemopoietic cells, and increase the number of hemopoietic clusters, hence enhancing hemopoietic function, including erythropoiesis、granulopoiesis and megakaryocytopoiesis. NK cells might exert their positive regulating effect on hemopoiesis through direct contact with hemopoietic stem cells or by purifying and improving the hemopoietic microenviroment, implicating that NK cells might play an important role in maintaining the balance of hemopoietic function in mice.