Daibata M, Mellinghoff I, Takagi S, Humphreys R E, Sairenji T
Department of Pharmacology, University of Massachusetts Medical School, Worcester 01655.
J Immunol. 1991 Jul 1;147(1):292-7.
The activation of phosphoprotein tyrosine kinases was studied in the regulation of EBV activation in Akata cells after cross-linking membrane IgG with anti-IgG. Protein tyrosine phosphorylation was induced in Akata cells after stimulation with anti-IgG, as determined by immunoblotting with the PY20 anti-phosphotyrosine mAb. The frequency of phosphotyrosine-activated cells was also measured by immunofluorescence with the PY20 antibody. Genistein, an inhibitor of tyrosine kinases, at non-cytotoxic doses blocked EBV activation, as measured in the induction of EBV Ag, EBV immediate early BZLF1 mRNA, and its protein product ZEBRA. Such inhibitions were reversed upon removing genistein from the cultures. Genistein inhibition of early Ag induction depended upon the time of addition of genistein after stimulation with anti-IgG. These findings indicate that activation of tyrosine kinase is required for EBV activation after cross-linking membrane IgG in Akata cells.
在用抗IgG交联膜IgG后，研究了磷蛋白酪氨酸激酶的激活在调控赤羽（Akata）细胞中EB病毒激活过程中的作用。用PY20抗磷酸酪氨酸单克隆抗体进行免疫印迹分析表明，在用抗IgG刺激后，赤羽细胞中诱导了蛋白酪氨酸磷酸化。还用PY20抗体通过免疫荧光法测定了磷酸酪氨酸激活细胞的频率。酪氨酸激酶抑制剂染料木黄酮在无细胞毒性剂量下可阻断EB病毒激活，这在EB病毒抗原、EB病毒即刻早期BZLF1 mRNA及其蛋白产物ZEBRA的诱导实验中得到了验证。从培养物中去除染料木黄酮后，这种抑制作用可被逆转。染料木黄酮对早期抗原诱导的抑制作用取决于在用抗IgG刺激后添加染料木黄酮的时间。这些发现表明，在赤羽细胞中交联膜IgG后，EB病毒激活需要酪氨酸激酶的激活。
