Willingham M C, Pastan I
J Cell Biol. 1974 Oct;63(1):288-94. doi: 10.1083/jcb.63.1.288.
We have devised a quantitative way to measure the agglutination of cells which utilizes the size discrimination feature of an automatic particle counter. With this method we have studied the agglutinability by concanavalin A of 3T3 cells, a mutant of 3T3 cells (3T3cAMP(tcs)) in which cyclic AMP levels fall when the cells are subjected to temperature change or fresh serum, and L929 cells. We find with 3T3cAMP(tcs) cells that low levels of cyclic AMP correlate with increased agglutinability and that high levels of cyclic AMP correlate with decreased agglutinability. Prior treatment of these cells with a cyclic AMP phosphodiesterase inhibitor or Bt(2)cAMP blocks the increase in agglutinability induced by temperature change. When 3T3 cells are treated with fresh serum, their agglutinability also increases although to a much smaller extent than with 3T3cAMP(tcs) cells. Cells change their agglutinability very rapidly. Treatment of L929 cells for 15 min with 1-methyl-3-isobutyl xanthine at 1 mM decreases their agglutinability to the level of normal 3T3 cells. We conclude that in normal and transformed cells the level of cyclic AMP regulates agglutinability.
我们设计了一种定量方法来测量细胞凝集，该方法利用了自动颗粒计数器的大小区分功能。通过这种方法，我们研究了3T3细胞、3T3细胞的一种突变体（3T3cAMP(tcs)，当细胞受到温度变化或新鲜血清刺激时，其环磷酸腺苷水平会下降）以及L929细胞对刀豆球蛋白A的凝集反应能力。我们发现，对于3T3cAMP(tcs)细胞，低水平的环磷酸腺苷与凝集反应能力增强相关，而高水平的环磷酸腺苷与凝集反应能力降低相关。用环磷酸腺苷磷酸二酯酶抑制剂或Bt(2)cAMP预先处理这些细胞，可阻断温度变化诱导的凝集反应能力增强。当用新鲜血清处理3T3细胞时，它们的凝集反应能力也会增加，尽管增加的程度比3T3cAMP(tcs)细胞小得多。细胞的凝集反应能力变化非常迅速。用1 mM的1-甲基-3-异丁基黄嘌呤处理L929细胞15分钟，可使其凝集反应能力降低至正常3T3细胞的水平。我们得出结论，在正常细胞和转化细胞中，环磷酸腺苷水平调节凝集反应能力。
