Salmon M, Bacon P A, Young S P
Department of Rheumatology, University of Birmingham, U.K.
Immunology. 1987 Sep;62(1):81-7.
Several reports suggest that natural killer (NK) cells recognize the transferrin receptor (TFR) as a target for killing, and that natural cytotoxicity may be involved in the control of stem cell proliferation in bone-marrow. This study tested whether NK-cell recognition of the TFR on activated lymphocytes plays a role in the control of peripheral immune responses. Six lymphoid lines were created from a single individual, and used as targets for cytotoxicity assays, using either peripheral blood mononuclear cells, or mixed lymphocyte reaction (MLR)-derived effectors. The cells responsible for killing were predominantly Leu-11+Leu-7+ NK cells, though CD3+ cells accounted for about 25% of cytotoxicity from MLR. No correlation was observed between TFR density and NK susceptibility when using all six cell lines. Specifically increasing the density of TFR on a single cell line failed to increase susceptibility to NK, suggesting that the TFR does not act as a major target for natural cytotoxicity directed at lymphoid cells. Furthermore, the relatively low levels of killing observed indicate that activated NK populations that accumulate at sites of immune response are unlikely to play a direct immunoregulatory role.
多项报告表明，自然杀伤（NK）细胞将转铁蛋白受体（TFR）识别为杀伤靶点，且自然细胞毒性可能参与骨髓中干细胞增殖的调控。本研究检测了NK细胞对活化淋巴细胞上TFR的识别是否在周围免疫反应的调控中发挥作用。从单个个体创建了6个淋巴细胞系，并将其用作细胞毒性测定的靶标，使用外周血单核细胞或混合淋巴细胞反应（MLR）衍生的效应细胞。负责杀伤的细胞主要是Leu-11+Leu-7+NK细胞，不过CD3+细胞约占MLR细胞毒性的25%。使用所有6个细胞系时，未观察到TFR密度与NK敏感性之间存在相关性。在单个细胞系上特异性增加TFR密度未能增加对NK的敏感性，这表明TFR并非针对淋巴细胞的自然细胞毒性的主要靶点。此外，观察到的相对较低的杀伤水平表明，在免疫反应部位积累的活化NK细胞群体不太可能发挥直接的免疫调节作用。
