Notter M F, Leary J F
J Cell Physiol. 1985 Dec;125(3):476-84. doi: 10.1002/jcp.1041250317.
A neuroblastoma cell line was assessed for its capacity to bind tetanus toxin (TT) by using immunofluorescence and flow cytometry to analyze cells on a single cell basis. A clone of Neuro 2a, N2AB-1, was shown to bind variable amounts of TT per cell and this binding could be saturated by increasing doses of the toxin. Toxin binding was specific for neuronal cells, as the non-neuronal cell line, C6 glioma, bound negligible amounts of toxin. Variability of immunofluorescence staining was due in part to the increase in size of N2AB-1 cells as they progress through the cell cycle as measured by cell surface densities of toxin binding and DNA levels by propidium iodide (PI) staining. When N2AB-1 cells were treated with exogenous gangliosides for 24 h, cells were induced to sprout neurites and cell growth was inhibited. Analysis of DNA histograms indicated that ganglioside treatment caused more cells to appear in G0G1 of the cell cycle than that seen for untreated controls. Upon cytometric analysis of TT binding to ganglioside treated cells, it was apparent that treatment stimulated all cells to bind TT in larger amounts per cell than that seen with untreated N2AB-1 cells. These data suggest that TT binding and, therefore, toxin receptors are constant in density throughout the cell cycle of these neuroblastoma cells and that exogenous gangliosides can cause differentiation followed by increased toxin binding.
通过免疫荧光和流式细胞术在单细胞水平分析细胞，评估一种神经母细胞瘤细胞系结合破伤风毒素（TT）的能力。神经2a（Neuro 2a）的一个克隆N2AB-1显示每个细胞结合的TT量不同，并且这种结合可被增加剂量的毒素饱和。毒素结合对神经元细胞具有特异性，因为非神经元细胞系C6胶质瘤结合的毒素量可忽略不计。免疫荧光染色的变异性部分归因于N2AB-1细胞在细胞周期进程中大小的增加，这通过毒素结合的细胞表面密度和碘化丙啶（PI）染色的DNA水平来衡量。当用外源性神经节苷脂处理N2AB-1细胞24小时时，细胞被诱导长出神经突并且细胞生长受到抑制。DNA直方图分析表明，与未处理的对照相比，神经节苷脂处理导致更多细胞出现在细胞周期的G0G1期。对TT与经神经节苷脂处理的细胞结合进行细胞计数分析时，很明显处理刺激所有细胞比未处理的N2AB-1细胞每个细胞结合更多量的TT。这些数据表明，在这些神经母细胞瘤细胞的整个细胞周期中，TT结合以及因此的毒素受体密度是恒定的，并且外源性神经节苷脂可导致分化，随后毒素结合增加。
