Vose B M, Blackledge G, Crowther D, Gallaher J
Immunology. 1982 Jul;46(3):619-27.
Human natural killer (NK) cells separated initially by density centrifugation of lymphocytes (E+) forming rosettes with sheep red blood cells (SRBC), were further fractionated on gradients of bovine serum albumin (BSA). Low density fractions contained effector cells which displayed high cytotoxicity against the NK-sensitive erythroleukaemic cell line, K562. These low density cells, which expressed receptors for Fc and the monoclonal antibody OKMI, showed enhanced cytotoxicity when treated with lymphoblastoid interferon (IFN-alpha). They also showed an increased response to phytomitogen in comparison with unseparated cells or those recovered from high density fractions. Two lymphocyte subsets one of high and one of low lectin binding capacity were identified in the E+ populations by their reactivity with Lens culinaris agglutinin (LCA). High LCA binding was observed only in low density fractions and was associated with a marked enrichment of NK activity. This property was used to separate the NK active population in E+ cells by fluorescence-activated cell sorting (FACS). These data add a new dimension to the cell surface properties of human NK cells and suggest the presence of LCA-reactive glycoproteins which are either enriched in, or uniquely associated with, cells of the NK subset. The experiments indicate that lectins can serve as useful probes of lymphocyte function and provide the basis for effective cell sorting.
最初通过淋巴细胞（E+）与绵羊红细胞（SRBC）形成玫瑰花结的密度离心法分离出的人自然杀伤（NK）细胞，再在牛血清白蛋白（BSA）梯度上进行进一步分级分离。低密度级分含有对NK敏感的红白血病细胞系K562表现出高细胞毒性的效应细胞。这些低密度细胞表达Fc受体和单克隆抗体OKM1，在用淋巴母细胞样干扰素（IFN-α）处理时表现出增强的细胞毒性。与未分离的细胞或从高密度级分中回收的细胞相比，它们对植物有丝分裂原的反应也增强。通过它们与扁豆凝集素（LCA）的反应性，在E+群体中鉴定出两个淋巴细胞亚群，一个具有高凝集素结合能力，另一个具有低凝集素结合能力。仅在低密度级分中观察到高LCA结合，并且与NK活性的显著富集相关。利用这一特性通过荧光激活细胞分选（FACS）分离E+细胞中的NK活性群体。这些数据为人类NK细胞的细胞表面特性增添了新的维度，并表明存在LCA反应性糖蛋白，其在NK亚群细胞中富集或与之独特相关。实验表明凝集素可作为淋巴细胞功能的有用探针，并为有效的细胞分选提供基础。
