THE CD45 TYROSINE PHOSPHATASE REGULATES SPECIFIC POOLS OF ANTIGEN RECEPTOR-ASSOCIATED P59(FYN) AND CD4-ASSOCIATED P56(LCK) TYROSINE KINASES IN HUMAN T-CELLS
THE CD45 TYROSINE PHOSPHATASE REGULATES SPECIFIC POOLS OF ANTIGEN RECEPTOR-ASSOCIATED P59(FYN) AND CD4-ASSOCIATED P56(LCK) TYROSINE KINASES IN HUMAN T-CELLS
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DOI：
10.1002/j.1460-2075.1994.tb06461.x
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发表时间：
1994-04-15
期刊：
影响因子：
11.4
通讯作者：
ALEXANDER, D
中科院分区：
文献类型：
--
作者：
BIFFEN, M;MCMICHAELPHILLIPS, D;ALEXANDER, D
一个新分离的T细胞系（CB 1）来自T-急性淋巴细胞白血病（T-ALL）患者包含的细胞（40%），不表达的CD 45磷酸酪氨酸磷酸酶。将细胞分选为CD 45（-）和CD 45（+）群体，并显示其来源为克隆。T细胞受体（TCR）与其CD 4/CD 8共受体的交联或共连接诱导了CD 45（+）细胞中的酪氨酸磷酸化和钙信号，但在CD 45（-）细胞中不诱导。出乎意料的是，与CD 35（+）细胞相比，CD 45（-）细胞中的全细胞p56（lck）和p59（fyn）酪氨酸激酶活性并未降低。因此，开发了一种新的技术来分离在细胞表面表达的聚集受体的特定池，以及它们相关的酪氨酸激酶。使用这种技术，它表明，细胞表面CD 4-p56（lck）激酶活性在CD 45（-）比在CD 45（+）细胞低78%。尽管p59（fyn）和TCR蛋白的水平相当，但在来自CD 45（+）而不是CD 45（-）细胞的TCR免疫复合物中发生TCR ζ和γ链的磷酸化。此外，CD 45（-）细胞中TCR相关酪氨酸激酶对外源性底物的活性比CD 45（+）细胞低84%。将重组p5（fyn）添加到从CD 45（-）细胞分离的TCR免疫复合物中，恢复了TCR ζ和γ链的磷酸化。我们的研究结果表明，CD 45选择性地调节p59（fyn）和p56（lck）激酶的池，这是与TCR和CD 4在细胞表面。这些受体相关激酶库的CD 45活化与TCR及其共受体偶联至细胞内信号传导途径的能力相关。
A newly isolated T-cell line (CB1) derived from a T-acute lymphoblastic leukaemia (T-ALL) patient contained cells (40% of total) which did not express the CD45 phosphotyrosine phosphatase. The cells were sorted into CD45(-) and CD45(+) populations and shown to be clonal in origin. T-cell receptor (TCR) cross-linking or coligation of the TCR with its CD4/CD8 co-receptors induced tyrosine phosphorylation and calcium signals in CD45(+) but not in CD45(-) cells. Unexpectedly, whole cell p56(lck) and p59(fyn) tyrosine kinase activities were not reduced in CD45(-) compared to CD35(+) cells. A novel technique was therefore developed to isolate specific pools of aggregated receptors expressed at the cell surface, together with their associated tyrosine kinases. Using this technique it was shown that cell surface CD4-p56(lck) kinase activity was 78% lower in CD45(-) than in CD45(+) cells. Phosphorylation of TCR zeta- and gamma-chains occurred in TCR immunocomplexes from CD45(+) but not CD45(-) cells, despite comparable levels of p59(fyn) and TCR proteins. Furthermore, TCR-associated tyrosine kinase activity towards an exogenous substrate was 84% lower in CD45(-) than in CD45(+) cells. Addition of recombinant p5(fyn) to TCR immunocomplexes isolated from CD45(-) cells restored the phosphorylation of the TCR zeta- and gamma-chains. Our results demonstrate that CD45 selectively regulates the pools of p59(fyn) and p56(lck) kinases which are associated with the TCR and CD4 at the cell surface. Activation by CD45 of these receptor-associated kinase pools correlates with the ability of the TCR and its co-receptors to couple to intracellular signalling pathways.