Dairaghi D J, Soo K S, Oldham E R, Premack B A, Kitamura T, Bacon K B, Schall T J
Department of Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94306, USA.
J Immunol. 1998 Jan 1;160(1):426-33.
The chemokine RANTES induces a unique biphasic cytoplasmic Ca2+ signal in T cells. The first phase of this signal, similar to that of other chemokines, is G-protein mediated and chemotaxis associated. The second phase of this signal, unique to RANTES and evident at concentrations greater than 100 nM, is tyrosine kinase linked and results in a spectrum of responses similar to those seen with antigenic stimulation of T cells. We show here that certain jurkat T cells responded to RANTES solely through this latter pathway. A direct correlation between the RANTES-induced second phase response and CD3 expression was demonstrated in these cells. Sorting the Jurkat cells into CD3(high) and CD3(low) populations revealed that only the CD3(high) cells were responsive to RANTES. Furthermore, stimulation of these Jurkat cells with anti-CD3 mAb significantly depresses their subsequent response to RANTES. While a RANTES-specific chemokine receptor is expressed at a low level on these Jurkat cells, the RANTES-induced activation is dependent on the presence of the TCR. Thus, stimulation through TCR may partially account for RANTES' unique pattern of signaling in T cells.
趋化因子RANTES在T细胞中诱导独特的双相细胞质Ca2+信号。该信号的第一阶段与其他趋化因子的信号相似，是由G蛋白介导且与趋化作用相关的。该信号的第二阶段是RANTES所特有的，在浓度大于100 nM时明显，是与酪氨酸激酶相关的，并导致一系列类似于T细胞抗原刺激所产生的反应。我们在此表明，某些Jurkat T细胞仅通过后一种途径对RANTES作出反应。在这些细胞中证实了RANTES诱导的第二阶段反应与CD3表达之间存在直接相关性。将Jurkat细胞分选成CD3(高)和CD3(低)群体，结果显示只有CD3(高)细胞对RANTES有反应。此外，用抗CD3单克隆抗体刺激这些Jurkat细胞会显著降低它们随后对RANTES的反应。虽然在这些Jurkat细胞上低水平表达一种RANTES特异性趋化因子受体，但RANTES诱导的激活依赖于TCR的存在。因此，通过TCR的刺激可能部分解释了RANTES在T细胞中独特的信号传导模式。
