INTRACELLULAR CA2+ POOLS IN JURKAT T-LYMPHOCYTES
INTRACELLULAR CA2+ POOLS IN JURKAT T-LYMPHOCYTES
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DOI：
10.1042/bj2910447
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发表时间：
1993-04-15
影响因子：
4.1
通讯作者：
EMMRICH, F
中科院分区：
文献类型：
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作者：
GUSE, AH;ROTH, E;EMMRICH, F
Jurkat T淋巴细胞包含至少四个细胞内Ca 2+池。池I是激动剂敏感的，并且包含总Ca 2+储存容量的23+/-8%（n = 18），如在EGTA存在下的完整细胞中所示。激动剂诱导的Ins（1，4，5）P3的形成和从池I的Ca 2+释放的时间过程几乎是重叠的，表明激动剂敏感的池I被Ins（1，4，5）P3清空。同样地，在透化细胞中，Ins（1，4，5）P3敏感的Ca 2+池I的大小为27+/-11%（n = 14）。池II含有26+/-5%（n = 9）的细胞内储存的Ca 2+，并由毒胡萝卜素（一种内质网（ER）Ca 2 +-ATP酶抑制剂）释放。在加入激动剂之前加入毒胡萝卜素可消除激动剂诱导的完整和透化细胞中的Ca 2+释放，表明池I是ER Ca 2+池的一个亚室。该ER Ca 2+池（池I和II）的含量在完整细胞中为51+/-15%（n = 9），在透化细胞中为49+/-16%（n = 16）。咖啡因释放Ca 2+，即使当ER池（池I和II）被清空之前添加毒胡萝卜素，表明存在独立于池I和II的第三个池。样本池III中完整细胞占23+/-6%（n = 8），透化细胞占41+/-8%（n = 5）。通过加入Ca 2+离子载体离子霉素释放剩余的胞内储存的Ca 2+。该第四个池含有27+/-8%（n = 9）的完整细胞，但小于100。在透化细胞中。池III的大小增加时，池I和II被清空，然后再加入咖啡因，而池IV的大小在这种条件下减少。总之，这第一次全面描述Jurkat T淋巴细胞中的细胞内钙池证明了四种不同的钙池的存在，提供了它们的大小估计，并描述了彼此之间的关系。从池I [Ins（1，4，5）P3-敏感]释放的Ca 2+先前已被证明在T细胞活化中起主要作用，而池II-IV的生理作用仍有待建立。
Jurkat T-lymphocytes comprise at least four intracellular Ca2+ pools. Pool I was agonist-sensitive and contained 23+/-8% (n = 18) of the total Ca2+-storage capacity, as shown in intact cells in the presence of EGTA. The time courses of the agonist-induced formation of Ins(1,4,5)P3 and of the Ca2+ release from pool I were nearly superimposable, indicating that the agonist-sensitive pool I is emptied by Ins(1,4,5)P3. Likewise, in permeabilized cells, the size of the Ins(1,4,5)P3-sensitive Ca2+ pool I was 27+/-11% (n = 14). Pool II contained 26+/-5% (n = 9) of intracellularly stored Ca2+ and was liberated by thapsigargin, an inhibitor of the endoplasmic-reticulum (ER) Ca2+-ATPase. Addition of thapsigargin before addition of agonist abolished the agonist-induced Ca2+ release in both intact and permeabilized cells, indicating that pool I is a subcompartment of the ER Ca2+ pool. The content of this ER Ca2+ pool (pools I and II) amounted to 51+/-15 % (n = 9) in intact cells and 49+/-16 % (n = 16) in permeabilized cells. Caffeine released Ca2+ even when the ER pool (pools I and II) was emptied by previous addition of thapsigargin, indicating the presence of a third pool independent of pools I and II. Pool III contained 23+/-6% (n = 8) in intact cells, but 41+/-8% (n = 5) in permeabilized cells. The remaining intracellularly stored Ca2+ was released by addition of the Ca2+ ionophore ionomycin. This fourth pool contained 27+/-8% (n = 9) in intact cells, but less than 10 0. in permeabilized cells. The size of pool III was increased when pools I and II were emptied before addition of caffeine, whereas the size of pool IV was decreased under such conditions. In conclusion, this first comprehensive description of intracellular Ca2+ pools in Jurkat T-lymphocytes demonstrates the presence of four different Ca2+ pools, provides estimates of their sizes and describes relationships between each other. Release of Ca2+ from pool I [Ins(1,4,5)P3-sensitive] has previously been shown to play a major role in T-cell activation, whereas the physiological role of pools II-IV remains to be established.