O'Connor R, Torigoe T, Reed J C, Santoli D
Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
Blood. 1992 Aug 15;80(4):1017-25.
We have previously reported the establishment of an interleukin-3 (IL-3)-dependent and phenotypically myeloid cell line (TALL-103/3), obtained by culturing cells from an immature T-lymphoblastic leukemia in the presence of IL-3. These cells differentiated into a T-lymphoid cell line (TALL-103/2) upon removal of IL-3 and incubation in IL-2. Despite the different phenotype, the two cell lines remained karyotypically and genotypically identical. Here, we have analyzed the phenotypic changes and the signaling events induced by these two lymphokines in TALL-103/3 cells by switching them to temporary growth in IL-2 and returning them to IL-3. All four sublines obtained (the myeloid in IL-3 and the lymphoid in IL-2) expressed RNA for CD3, IL-2 receptor (R) alpha, and T-cell receptor (TCR)-gamma and -delta chains. However, cells cultured in IL-3 failed to express detectable levels of the IL-2R beta chain at both the protein and RNA levels, whereas cells exposed to IL-2 always expressed IL-2R beta. In parallel with the changes in IL-2R beta expression, the SRC-like protein tyrosine kinase (PTK) p56 LCK could not be detected in IL-3-dependent cells, but was abundant in the IL-2-dependent cells and underwent markedly increased autophosphorylation in response to IL-2. In contrast, p53/p56 LYN was highly expressed in IL-3-dependent cells, and greatly decreased when these cells were switched to growth in IL-2. LYN kinase autophosphorylation modestly increased in response to IL-3. None of the other kinases in the SRC family that were tested underwent increased autophosphorylation after lymphokine stimulation, indicating the specificity of IL-2 for LCK and of IL-3 for LYN. The TALL-103 cell lines provide a unique system to study the interaction between lymphokines and SRC-family PTKs in signal transduction pathways leading to hematopoietic cell differentiation.
我们先前曾报道建立了一种白细胞介素-3（IL-3）依赖且表型为髓样的细胞系（TALL-103/3），该细胞系是通过在IL-3存在的情况下培养来自未成熟T淋巴细胞白血病的细胞获得的。去除IL-3并在IL-2中培养后，这些细胞分化为T淋巴细胞系（TALL-103/2）。尽管表型不同，但这两个细胞系在核型和基因型上仍保持一致。在此，我们通过将TALL-103/3细胞转换为在IL-2中短暂生长然后再回到IL-3中，分析了这两种淋巴因子在这些细胞中诱导的表型变化和信号转导事件。获得的所有四个亚系（IL-3中的髓样亚系和IL-2中的淋巴样亚系）均表达CD3、IL-2受体（R）α以及T细胞受体（TCR）-γ和-δ链的RNA。然而，在IL-3中培养的细胞在蛋白质和RNA水平上均未能表达可检测水平的IL-2Rβ链，而暴露于IL-2的细胞总是表达IL-2Rβ。与IL-2Rβ表达的变化同时，在依赖IL-3的细胞中未检测到SRC样蛋白酪氨酸激酶（PTK）p56 LCK，但在依赖IL-2的细胞中含量丰富，并且在对IL-2的反应中自磷酸化明显增加。相反，p53/p56 LYN在依赖IL-3的细胞中高度表达，当这些细胞转换为在IL-2中生长时则大大降低。LYN激酶的自磷酸化在对IL-3的反应中适度增加。在测试的SRC家族的其他激酶中，没有一种在淋巴因子刺激后自磷酸化增加，这表明IL-2对LCK具有特异性，而IL-3对LYN具有特异性。TALL-103细胞系为研究淋巴因子与SRC家族PTK在导致造血细胞分化的信号转导途径中的相互作用提供了一个独特的系统。
