应用单克隆抗体分离各淋巴细胞亚群，测定各亚群对肿瘤细胞的杀伤活性。结果表明：除ＮＫ细胞外，ＣＤ４、ＣＤ８、Ｂ细胞均能单独杀伤肿瘤细胞，但以ＮＫ细胞杀伤力最强，ＣＤ４与ＮＫ细胞有协同杀伤作用。各互补群细胞的杀伤效应均比该亚群杀伤力强。低剂量辐射对全淋巴细胞和ＮＫ细胞的ＮＫ活性有不同效应。本研究说明只有用单抗分离的ＮＫ细胞，其杀伤活性才能称之为“ＮＫ细胞活性”。 Monoclonal antibodies were used to isolate each lymphocyte subpopulation, and the killing activity of each subpopulation on the tumor cells was determined. The results showed that except NK cells, CD4, CD8 and B cells could kill tumor cells alone, but NK cells had the strongest lethality and CD4 and NK cells had a synergistic cytotoxic effect. The killing effect of each complementary group of cells than the sub-group lethal. Low doses of radiation have different effects on NK activity of whole lymphocytes and NK cells. This study shows that only with monoclonal antibody isolated NK cells, its killing activity can be called “NK cell activity.”