自然杀伤细胞(Natural killer cell,下称NK细胞)是目前已知体内主要杀伤细胞之一。它除参与消灭(或清除)感染病毒或细菌的细胞外,还与肿瘤细胞的杀伤破坏有密切关系,其杀伤作用不需要任何抗原刺激,或抗体、补体的参与。有人认为NK细胞是机体对早期肿瘤的免疫监视的一种效应细胞。此外,NK细胞在组织移植后排斥反应的发生、调节正常造血干细胞的分化和增殖以及维持内环境稳定也起着重要作用。因此,研究NK细胞的活性具有一定的意义。 Natural killer cells (NK cells) are one of the major killer cells known in the body. In addition to participating in the elimination (or clearance) of cells infected with viruses or bacteria, it is also closely related to the destruction of tumor cells. The killing effect does not require any antigen stimulation, or the participation of antibodies and complement. Some people think that NK cells are the effector cells of the body for the immune surveillance of early tumors. In addition, NK cells play an important role in rejection after tissue transplantation, regulation of differentiation and proliferation of normal hematopoietic stem cells, and maintenance of homeostasis. Therefore, the study of NK cell activity has a certain significance.