Boyer C, Ley S, Davies A, Crumpton M
Cell Surface Biochemistry Laboratory, Imperial Cancer Research Fund, London, U.K.
Mol Immunol. 1993 Jul;30(10):903-10. doi: 10.1016/0161-5890(93)90014-3.
Phosphotyrosyl polypeptides induced following CD3- or CD2- specific antibody stimulation were analysed in different human T cell lines by immunoblotting or by immunoprecipitation of 32P-labelled cell lysates using a phosphotyrosine-specific monoclonal antibody. In Jurkat cells, resting peripheral T lymphocytes, T lymphoblasts, CD8+ T lymphoblasts and a CD4+ T cell clone, CD3 stimulation induced a strong but transient tyrosine phosphorylation of at least 15 polypeptides. However, in peripheral T cells and T blasts, the kinetics of phosphorylation were considerably slower than in Jurkat cells. The pattern of phosphotyrosyl polypeptides induced by CD3 stimulation was similar, although some differences were noted between normal T cells and Jurkat, especially at the level of the extent of phosphorylation. As had been previously reported for Jurkat T cells, a qualitatively similar tyrosine phosphorylation response was induced upon CD2 or CD3 stimulation in each of the analysed T cell populations, suggesting that CD3 and CD2 share a common pathway of protein tyrosine kinase (PTK) activation. In HPB. ALL leukemia T cells (which express very low levels of CD45), both CD3 and CD2 stimulation induced only very weak protein tyrosyl phosphorylation. However, a 50 kDa polypeptide, which was part of an inducible doublet in Jurkat or normal T lymphocytes, was constitutively tyrosyl-phosphorylated in the HPB. ALL line. These results suggest that there is a common pathway of early PTK activation following CD3- or CD2-mediated stimulation in mature T cells, whether they express surface CD4 or CD8, and also that the PTK may be differently regulated in different T cell populations leading to different kinetics or intensity of tyrosyl phosphorylation.
通过免疫印迹法，或使用磷酸酪氨酸特异性单克隆抗体对32P标记的细胞裂解物进行免疫沉淀，分析了不同人T细胞系中CD3或CD2特异性抗体刺激后诱导产生的磷酸酪氨酸多肽。在Jurkat细胞、静息外周T淋巴细胞、T淋巴母细胞、CD8 + T淋巴母细胞和一个CD4 + T细胞克隆中，CD3刺激诱导了至少15种多肽的强烈但短暂的酪氨酸磷酸化。然而，在外周T细胞和T淋巴母细胞中，磷酸化动力学比Jurkat细胞慢得多。CD3刺激诱导的磷酸酪氨酸多肽模式相似，尽管正常T细胞和Jurkat细胞之间存在一些差异，特别是在磷酸化程度水平上。正如之前关于Jurkat T细胞的报道，在每个分析的T细胞群体中，CD2或CD3刺激均诱导了定性相似的酪氨酸磷酸化反应，这表明CD3和CD2共享蛋白酪氨酸激酶（PTK）激活的共同途径。在HPB.ALL白血病T细胞（表达非常低水平的CD45）中，CD3和CD2刺激均仅诱导了非常弱的蛋白酪氨酸磷酸化。然而，一种50 kDa的多肽，它是Jurkat或正常T淋巴细胞中诱导性双峰的一部分，在HPB.ALL细胞系中组成性地酪氨酸磷酸化。这些结果表明，在成熟T细胞中，无论是表达表面CD4还是CD8，CD3或CD2介导的刺激后都存在早期PTK激活的共同途径，并且PTK在不同T细胞群体中可能受到不同调节，导致酪氨酸磷酸化的动力学或强度不同。
