Jewett A, Bonavida B
Department of Microbiology and Immunology, University of California at Los Angeles School of Medicine.
Cell Immunol. 1995 Jan;160(1):91-7. doi: 10.1016/0008-8749(95)80013-9.
This study examined the characteristics of functional anergy of natural killer cells (NK) following their interaction with target cells. Purified NK cells were cocultured with K562 for 15 min or 4 hr to allow for binding of targets to NK cells. The resulting NK-target conjugates were then dissociated by EDTA, and the unbound NK cells were separated from the targets by flow cytometry and cell sorting. Compared to untreated NK cells, the K562-dissociated NK cells were inhibited for cytotoxic function as assessed by the 51Cr release assay and by the single killer frequency assay and also responded poorly following activation by IL-2 or IFN-alpha. The inactivated NK cells had a diminished ability to reform conjugates with the target cells. Following cell sorting of the NK subsets, the conjugate subset had the least cytotoxic activity when compared to both the free NK subset or the unfractionated NK population. The IL-2 response observed with the unfractionated anergic NK cells was found to be due to the activation of the NK free cell subset while the conjugate subset was poorly responsive to IL-2. The cell surface CD16, CD2, and CD56 antigen expression was downmodulated in the conjugate subset but not in the free cells. However, the CD69 surface expression was significantly upregulated on the surface of the NK conjugate subset and was potentiated following treatment with IFN-alpha and IL-2. These results demonstrate that target-mediated anergy of NK cells is restricted to the NK-target conjugate subset while sparing the remaining free cell subset. Further, the findings demonstrate that the anergic NK cells express the phenotype CD16dimCD2dimCD56dimCD69brightCD11bbright.
本研究检测了自然杀伤细胞（NK）与靶细胞相互作用后功能无能的特征。将纯化的NK细胞与K562共培养15分钟或4小时，以使靶细胞与NK细胞结合。然后用乙二胺四乙酸（EDTA）解离产生的NK-靶细胞结合物，并通过流式细胞术和细胞分选将未结合的NK细胞与靶细胞分离。与未处理的NK细胞相比，经K562解离的NK细胞的细胞毒性功能受到抑制，这通过51铬（51Cr）释放试验和单杀伤频率试验评估，并且在白细胞介素-2（IL-2）或α干扰素（IFN-α）激活后反应也较差。失活的NK细胞与靶细胞重新形成结合物的能力减弱。对NK亚群进行细胞分选后，与游离NK亚群或未分级的NK群体相比，结合物亚群的细胞毒性活性最低。发现未分级的无能NK细胞对IL-2的反应是由于游离NK细胞亚群的激活，而结合物亚群对IL-2反应较差。结合物亚群中细胞表面CD16、CD2和CD56抗原表达下调，但游离细胞中未下调。然而，NK结合物亚群表面的CD69表面表达显著上调，并且在用IFN-α和IL-2处理后增强。这些结果表明，靶细胞介导的NK细胞无能仅限于NK-靶细胞结合物亚群，而其余游离细胞亚群未受影响。此外，研究结果表明，无能NK细胞表达CD16dimCD2dimCD56dimCD69brightCD11bbright表型。
