Giri J G, Anderson D M, Kumaki S, Park L S, Grabstein K H, Cosman D
Immunex Research and Development Corporation, Seattle, WA 98101, USA.
J Leukoc Biol. 1995 May;57(5):763-6. doi: 10.1002/jlb.57.5.763.
Interleukin 15 is a newly discovered cytokine that shares biological activities with IL-2 and, like IL-2, is a member of the four-helix bundle cytokine family. We have shown that IL-15 shares components of the receptor for IL-2: the alpha chain of the IL-2R is not required, but both the beta and gamma chains are needed for IL-15 mediated bioactivities. A defect in IL-15 signaling may therefore contribute to the phenotype of X-linked severe combined immunodeficiency in humans, resulting from mutations in the common gamma chain. Differential ability of cells to bind and respond to IL-2 and IL-15 suggested the existence of an additional IL-15 specific receptor component. We identified an IL-15 specific binding protein (IL-15R alpha) on a murine T cell and isolated the corresponding cDNA. The IL-15R alpha is not a member of the hematopoietin receptor superfamily, but is structurally related to the alpha chain of the IL-2R. Differences in the expression pattern of IL-15 and its receptor compared to the IL-2 system suggest unique in vivo roles for IL-15.
白细胞介素15是一种新发现的细胞因子，它与白细胞介素2具有共同的生物学活性，并且与白细胞介素2一样，是四螺旋束细胞因子家族的成员。我们已经表明，白细胞介素15与白细胞介素2的受体有共同的组成部分：白细胞介素2受体的α链不是必需的，但β链和γ链对于白细胞介素15介导的生物活性都是必需的。因此，白细胞介素15信号传导缺陷可能导致人类X连锁严重联合免疫缺陷的表型，这是由共同γ链的突变引起的。细胞结合和响应白细胞介素2和白细胞介素15的能力差异表明存在额外的白细胞介素15特异性受体成分。我们在小鼠T细胞上鉴定出一种白细胞介素15特异性结合蛋白（白细胞介素15Rα）并分离出相应的cDNA。白细胞介素15Rα不是造血受体超家族的成员，但在结构上与白细胞介素2受体的α链相关。与白细胞介素2系统相比，白细胞介素15及其受体表达模式的差异表明白细胞介素15在体内具有独特的作用。
