Demaison C, Fiette L, Blanchetière V, Schimpl A, Thèze J, Froussard P
Unité d'Immunogénétique Cellulaire, Institut Pasteur, Paris, France.
J Immunol. 1998 Aug 15;161(4):1977-82.
The IL-2R is composed of three chains: IL-2R alpha, IL-2R beta, and IL-2R gamma. In mice, IL-2Ra is critical and determines IL-2 binding to the tripartite IL-2R complex. To extend our previous studies, which demonstrated that IL-2 regulates IL-2R alpha expression in vitro, we have analyzed expression in IL-2-deficient mice in vivo. As in control animals, CD4- CD8- thymocytes and bone marrow-derived B220+ pre-B cells were IL-2R alpha positive. In contrast, activated lymph node and splenic CD4 T cells (CD4+ CD69+) were found to be IL-2R alpha negative, whereas approximately 20% of the same cell populations from the MLR/lpr strain, which also accumulate large numbers of CD4-activated T cells in the presence of intact IL-2, retained expression. A similar pattern of IL-2R alpha expression was found among splenic CD8 cells from IL-2(-/-) and IL-2(+/-) animals. These findings demonstrate that in primary lymphoid organs, IL-2 is not directly involved in IL-2R alpha expression. However, at the level of mature lymphocytes, and more specifically CD4 T cells, IL-2 remains in vivo, as in vitro, the most critical cytokine controlling both IL-2R alpha expression and sensitivity to IL-2.
白细胞介素-2受体（IL-2R）由三条链组成：IL-2Rα、IL-2Rβ和IL-2Rγ。在小鼠中，IL-2Rα至关重要，并决定IL-2与三方IL-2R复合物的结合。为了扩展我们之前的研究（该研究表明IL-2在体外调节IL-2Rα的表达），我们分析了IL-2缺陷小鼠体内的表达情况。与对照动物一样，CD4-CD8-胸腺细胞和骨髓来源的B220+前B细胞的IL-2Rα呈阳性。相比之下，活化的淋巴结和脾脏CD4 T细胞（CD4+CD69+）被发现IL-2Rα呈阴性，而来自MLR/lpr品系的相同细胞群体中约20%在完整IL-2存在的情况下也积累了大量活化的CD4 T细胞，这些细胞保留了IL-2Rα的表达。在IL-2(-/-)和IL-2(+/-)动物的脾脏CD8细胞中也发现了类似的IL-2Rα表达模式。这些发现表明，在初级淋巴器官中，IL-2不直接参与IL-2Rα的表达。然而，在成熟淋巴细胞水平，更具体地说是CD4 T细胞水平，IL-2在体内仍然像在体外一样，是控制IL-2Rα表达和对IL-2敏感性的最关键细胞因子。
